AN ACOUSTIC ANALYSIS OF HERITAGE SPANISH VOWELS
Rebecca E. Ronquest
Submitted to the faculty of the University Graduate School in partial fulfillment of the requirements
for the degree Doctor of Philosophy
in the Department of Spanish and Portuguese, Indiana University
July 2012
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Accepted by the Graduate Faculty, Indiana University, in partial fulfillment of the requirements for the degree of Doctor of Philosophy.
Doctoral Committee _________________________________ Erik W. Willis, Ph.D.
Chair
_________________________________ Kimberly L. Geeslin, Ph.D.
_________________________________ Manuel Díaz-Campos, Ph.D.
_________________________________ Kenneth de Jong, Ph.D.
May 25, 2012
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©2012 Rebecca E. Ronquest
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ACKNOWLEDMENTS
This dissertation could not have been completed without the help and support of
so many individuals. First and foremost, I would like to thank my committee for their
guidance throughout this process. Thanks to Ken de Jong for sharing his knowledge and
experience with me, and for providing me (and my collection of animal-shaped mittens)
with a sound foundation in acoustic phonetics. I would also like to thank Manuel Díaz-
Campos for his insightful comments on this work, and for inviting me to participate in
collaborative projects at various points throughout my graduate career. Thanks to
Kimberly Geeslin for all the support and advice, quick and thoughtful responses to my
many frantic e-mails, and for offering additional insight into this project. I would like to
express my deepest gratitude to my advisor, Erik Willis, for teaching me the importance
of the viaje; for e-mails in the form of talking cats and crickets; and most of all, for
endless encouragement and patience.
Special thanks to the Latino Studies Program at Indiana University and John
Nieto-Phillips for the fellowship opportunity that provided me with the time and
resources to complete this work. I am very grateful to Kim Potowski for inspiring me to
study heritage speakers, and for assistance in recruiting participants and reserving space
for recording sessions. Special thanks also to Stephanie Dickinson at the Indiana
Statistical Consulting Center for help in designing the statistical model and interpreting
the results. Finally, thanks to Jon Tweedy for creating the Euclidean distance calculator,
and for support and friendship throughout this process.
I am extremely fortunate to have had the opportunity to work with so many
talented people throughout my academic career, all of whom have inspired my love of
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Spanish and linguistics: Clancy Clements, Jonathan Arries, George Greenia, Silvia
Tandeciarz, and Marliss Arruda, to name a few. I would also like to thank David Pisoni,
Luis Hernández, and Susie Levi – my mentors in the Speech Research Laboratory –
whose instruction and training have made me a stronger and more skilled researcher.
I am thankful to have had so many wonderful friends to help me through the
dissertation writing process with their ánimo and smiles: Erin Mcnulty, Greg Newall,
Catalina Méndez Vallejo, Scott Lamanna, Paul Malovrh, Lauren Schmidt, Marda Rose,
Tanya Flores, and Janet Smith. I would also like to thank my dear friends Jane and
Walter Gantz for their encouragement and wisdom, and for motivating me to write (and
swim) every day. I extend my sincerest thanks to James Moskowitz and Antje
Schwennicke for their incredible friendship and support over the past several years. From
doggie play dates and flag football games, to somehow getting me on a plane to Los
Angeles, they have been there through it all.
Last of all, and perhaps most importantly, special thanks to my mom, Bette
Ronquest, who has always believed that I could achieve this goal and any other that I set
out to accomplish. My achievements would not have been possible without her love and
support.
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Rebecca E. Ronquest
AN ACOUSTIC ANALYSIS OF HERITAGE SPANISH VOWELS
The present dissertation has two main goals: 1) to provide a descriptive, acoustic
characterization of the heritage Spanish vowel system and 2) to assess the extent to which
linguistic and extralinguistic variables affect heritage Spanish vowel production. Via
acoustic analysis of the vowel productions of heritage speakers (i.e. early bilinguals), this
investigation contributes to our understanding of bilingual Spanish vowel pronunciation,
offering insight into the types of variation the system can exhibit.
Sixteen heritage speakers of Spanish from the Midwestern United States
completed three speech elicitation tasks, background and cultural sensitivity
questionnaires (Cushner, 1986), and a grammar proficiency test (Geeslin & Gudmestad,
2010). The first and second formant frequencies, Euclidean distance from the center of
the vowel space, and the duration of each speaker’s vowels were calculated. The acoustic
data were further coded for a series of linguistic variables (lexical stress, syllable type,
speech style) and extralinguistic variables (course level, grammar proficiency, travel
frequency, Spanish use, and cultural sensitivity). Mixed linear models were conducted in
order to determine how the linguistic and extralinguistic factors impacted pronunciation.
The heritage Spanish vowel system was found to differ considerably from
traditional descriptions of monolingual Spanish vowel configurations. The /e/ was
produced further back in the acoustic space, the /u/ further front, and atonic vowels were
centralized and significantly shorter in duration than their tonic counterparts. The effect
of syllable type on vowel pronunciation was inconsistent, lending evidence against the
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presence of “open/closed” mid vowel allophony in this variety of Spanish. The impact of
speech style, however, was robust: vowels became longer and more greatly dispersed as
speech style became less natural. Finally, frequent travel abroad and Spanish use outside
of the classroom -- two characteristics known to impact the acquisition of L2
pronunciation -- resulted in an expansion of the vowel space that more closely
approximated native speaker norms. Overall, the acoustic and statistical results indicate
that although heritage speakers are often argued to exhibit “native-like” pronunciation,
their vowel system is not identical to that of a monolingual: it is unique and is influenced
by a variety of linguistic and extralinguistic factors.
____________________________________
____________________________________
____________________________________
____________________________________
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TABLE OF CONTENTS
LIST OF TABLES ............................................................................................................. xi
LIST OF FIGURES .......................................................................................................... xii
1 INTRODUCTION ...................................................................................................... 1
1.1 Previous linguistic research on heritage populations ........................................... 2
1.2 Spanish vowel systems ......................................................................................... 4
1.3 Goals..................................................................................................................... 6
1.4 Contributions ........................................................................................................ 7
1.5 Dissertation outline .............................................................................................. 9
2 PREVIOUS LITERATURE ..................................................................................... 10
2.1 Heritage speakers ............................................................................................... 10
2.1.1 Who are heritage speakers, and why should we learn more about them? ....... 11
2.1.2 Early bilingual and heritage pronunciation...................................................... 19
2.2 Vowel systems.................................................................................................... 29
2.2.1 General properties of vowels ........................................................................... 30
2.2.2 Impressionistic studies of Spanish vowels ....................................................... 36
2.2.3 Acoustic studies of Spanish vowels ................................................................. 49
2.3 Bilingual and contact vowel systems ................................................................. 72
2.3.1 Bilingual and contact Spanish vowel systems ................................................. 72
2.3.2 English vowel systems of heritage Spanish speakers ...................................... 83
2.4 Individual speaker characteristics and speech production ................................. 96
2.5 Research questions and hypotheses.................................................................. 102
3 METHODOLOGY ................................................................................................. 108
3.1 Instruments ....................................................................................................... 108
3.1.1 Narrative retelling task ................................................................................... 108
3.1.2 Picture identification task .............................................................................. 110
3.1.3 Carrier phrase task ......................................................................................... 114
3.1.4 Language background questionnaire ............................................................. 116
3.1.5 Grammar proficiency test .............................................................................. 116
3.1.6 Cultural sensitivity questionnaire .................................................................. 117
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3.2 Participants ....................................................................................................... 117
3.3 Procedure .......................................................................................................... 119
3.4 Data analysis .................................................................................................... 120
3.4.1 Acoustic measures ......................................................................................... 121
3.4.2 Individual variables ........................................................................................ 136
3.4.3 Statistical analyses ......................................................................................... 140
4 RESULTS ............................................................................................................... 145
4.1 Within-subjects variables ................................................................................. 145
4.1.1 Main effects and simple interactions ............................................................. 147
4.1.2 Complex interactions .................................................................................... 182
4.1.3 Summary of within-subjects effects.............................................................. 205
4.2 Between-subjects variables .............................................................................. 210
4.2.1 Course level .................................................................................................. 212
4.2.2 Frequency of travel ....................................................................................... 217
4.2.3 Grammar proficiency .................................................................................... 222
4.2.4 Spanish use.................................................................................................... 227
4.2.5 Cultural sensitivity ........................................................................................ 231
4.2.6 Summary of between-subjects effects .......................................................... 234
4.3 Overall summary of results .................................................................................. 237
5 DISCUSSION ......................................................................................................... 243
5.1 Overall distribution and organization of HS vowels ........................................ 243
5.2 Within-subjects variables ................................................................................. 258
5.2.1 Lexical stress ............................................................................................. 259
5.2.2 Syllable type.............................................................................................. 264
5.2.3 Speech style .............................................................................................. 270
5.3 Between-subjects variables .............................................................................. 277
5.3.1 Course level .............................................................................................. 277
5.3.2 Grammar proficiency ................................................................................ 282
5.3.3 Travel ........................................................................................................ 285
5.3.4 Spanish use................................................................................................ 290
5.3.5 Cultural sensitivity .................................................................................... 292
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5.4 Interpreting the expansion effect ...................................................................... 295
5.5 Limitations and future directions ..................................................................... 300
5.5.1 Experimental design.................................................................................. 300
5.5.2 Language and identity ............................................................................... 309
5.5.3 Control data ............................................................................................... 312
5.6 Summary of discussion .................................................................................... 315
6 CONCLUSIONS..................................................................................................... 320
REFERENCES ............................................................................................................... 326
Appendix A: List of words presented in the picture identification task (PIT) ............... 340
Appendix B: List of words presented in the carrier phrase task (CPT) ......................... 341
Appendix C: Language background questionnaire ........................................................ 342
Appendix D: Grammar proficiency Test (Spanish) ....................................................... 347
Appendix E: Language attitude and cultural sensitivity questionnaire ......................... 350
Appendix F: Participant demographic information ....................................................... 355
Appendix G: Total vowels analyzed in the analyses ..................................................... 358
Appendix H: Results of statistical analyses conducted with F1 .................................... 367
Appendix I: Results of statistical analyses conducted with F2 ...................................... 376
Appendix J: Results of statistical analyses conducted with Euclidean distance. ........... 386
Appendix K: Results of statistical analyses conducted with duration. .......................... 397
Appendix L: Normalized and non-normalized formant values ..................................... 405
Appendix M: Vowel by task by travel interaction ......................................................... 406
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LIST OF TABLES
Table 2-1. Spanish vowel system based on articulatory parameters .............................. 30 Table 2-2. Vowel pronunciation described in Navarro-Tomás (1918) ........................... 39 Table 3-1. Variables included in the Mixed Linear Model ........................................... 144 Table 4-1. Basic characteristics of vowels produced by male HS ................................ 146 Table 4-2. Basic characteristics of vowels produced by female HS ............................. 146 Table 4-3. F1, F2, and Euclidean distance measures of HS vowels ............................. 148 Table 4-4. Overall HS vowel duration .......................................................................... 153 Table 4-5. F1, F2, and Euclidean distance measures according to stress context ........ 157 Table 4-6. Atonic and tonic HS vowel duration ........................................................... 161 Table 4-7. F1, F2, and Euclidean distances of HS vowels by syllable type ................. 164 Table 4-8. Vowel duration in closed and open syllables .............................................. 167 Table 4-9. Formant values and Euclidean distance measures of HS vowels by task ... 171 Table 4-10. Vowel duration in each speech style .......................................................... 179 Table 4-11. Formant values and Euclidean distances by stress type in three tasks ....... 183 Table 4-12. Tonic and atonic vowel duration in three speech styles ............................. 192 Table 4-13. Formant values and Euclidean distances by syllable type in three tasks ... 196 Table 4-14. Vowel duration by syllable type in three tasks ........................................... 203 Table 4-15. Information pertaining to individual characteristics................................... 212 Table 4-16. Formant values and Euclidean distances for two course levels ................. 214 Table 4-17. Formant values and Euclidean distances for three travel groups ............... 219 Table 4-18. Summary of results ..................................................................................... 242
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LIST OF FIGURES
Figure 2-1. Figure of formant values reproduced from Quilis and Esgueva (1983). ....... 32 Figure 3-1. Images from the Tortilla Rag, narrative retelling task. ............................... 109 Figure 3-2. Sample training slide from PIT. .................................................................. 111 Figure 3-3. Model slide from actual task phase in the PIT. ........................................... 112 Figure 3-4. Slide of "strange" gift from the PIT. ........................................................... 113 Figure 3-5. Sample slides from CPT.............................................................................. 115 Figure 3-6. Waveform and spectrogram of the word tapa (“lid”). ................................. 123 Figure 3-7. Waveform and spectrogram for the word sistema (“system”). ................... 124 Figure 3-8. Waveform and spectrogram for the word mano (“hand”). ......................... 126 Figure 3-9. Waveform and spectrogram of the word un lápiz (“a pencil”). .................. 127 Figure 3-10. Waveform and spectrogram of the word cucharas (“spoons”). ................ 128 Figure 3-11. Representation of the centroid and distance of the point vowels from the centroid. .......................................................................................................................... 135 Figure 4-1. Overall acoustic distribution of HS vowels. ............................................... 149 Figure 4-2. Overall dispersion of HS vowels................................................................. 151 Figure 4-3. Overall dispersion of HS vowels with adjusted scale. ................................ 153 Figure 4-4. Overall vowel duration for all speakers. ..................................................... 154 Figure 4-5. Vowel duration based on acoustic distribution ........................................... 155 Figure 4-6. Tonic and atonic vowel productions for all speakers .................................. 158 Figure 4-7. Tonic and atonic vowel dispersion for all speakers .................................... 160 Figure 4-8. Tonic and atonic vowel duration for all speakers ....................................... 162 Figure 4-9. Acoustic distribution of vowels produced by all speakers in open and closed syllables........................................................................................................................... 165 Figure 4-10. Vowel dispersion based on syllable type. ................................................. 166 Figure 4-11. Vowel duration by syllable type. .............................................................. 168 Figure 4-12. Average vowel duration based on consonantal context. ........................... 169 Figure 4-13. Overall vowel space based on task (speech style). ................................... 172 Figure 4-14. Vowel dispersion based on task (speech style). ........................................ 177 Figure 4-15. Vowel duration based on task (speech style). ........................................... 180 Figure 4-16. Tonic and atonic vowel space in spontaneous speech (NRT). .................. 184 Figure 4-17. Tonic and atonic dispersion in spontaneous speech (NRT). ..................... 186 Figure 4-18. Tonic and atonic vowel space in semi-spontaneous speech (PIT). ........... 186 Figure 4-19. Tonic and atonic dispersion in semi-spontaneous speech (PIT). .............. 188 Figure 4-20. Tonic and atonic vowel space in controlled speech (CPT). ...................... 189 Figure 4-21. Tonic and atonic vowel dispersion in controlled speech (CPT). .............. 190 Figure 4-22. Tonic and atonic duration in each of the three speech styles, averaged across syllable type. ........................................................................................................ 193 Figure 4-23. Vowel space based on syllable type in spontaneous speech (NRT). ........ 197
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Figure 4-24. Vowel dispersion by syllable type in spontaneous speech (NRT). ........... 198 Figure 4-25. Vowel space based on syllable type in semi-spontaneous speech (PIT). . 199 Figure 4-26. Vowel dispersion by syllable type in semi-spontaneous speech (PIT). .... 200 Figure 4-27. Vowel space based on syllable type in controlled speech (CPT). ............. 201 Figure 4-28. Vowel dispersion by syllable type in controlled speech (CPT). ............... 202 Figure 4-29. Vowel duration in closed and open syllables in each task. ....................... 204 Figure 4-30. HS vowel production by course level. ...................................................... 215 Figure 4-31. Vowel distribution based on frequency of travel abroad.. ........................ 220 Figure 4-32. Vowel distribution based on grammar score: speakers 2f and 10f. .......... 224 Figure 4-33. Vowel distribution based on grammar score: speakers 10f and 7f ........... 225 Figure 4-34. Representation of vowel production based on Spanish use.. .................... 228 Figure 4-35. Vowel distribution based on cultural sensitivity. ...................................... 234 Figure 5-1. Overall vowel space for HS of Spanish ...................................................... 244 Figure 5-2. All vowel tokens produced by female HS ................................................... 247 Figure 5-3. All vowel tokens produced by male HS ...................................................... 247 Figure 5-4. Dispersion of vowel categories for female HS. .......................................... 249 Figure 5-5. Dispersion of vowel categories for male HS............................................... 250 Figure 5-6. Comparison of vowels produced by 13 female HS to vowels produced by 2 monolingual females in S&R (2001). ............................................................................. 252 Figure 5-7. Comparison of vowels produced by 3 male HS to vowels produced by 2 monolingual males in S&R (2001). ................................................................................ 253 Figure 5-8. HS and monolingual vowel duration in controlled speech. ........................ 256 Figure 5-9. Dispersion of normalized male and female vowels in the CPT. ................. 272 Figure 5-10. Dispersion of normalized male and female vowels in the PIT. ................ 272 Figure 5-11. Dispersion of normalized male and female vowels in the NRT. .............. 273 Figure 5-12. Normalized formant values for speakers enrolled in intermediate and advanced-level courses. .................................................................................................. 280 Figure 5-13. Vowel production in three speech tasks for the non-travel group. ............ 296 Figure 5-14. Vowel production in three speech tasks for the infrequent travel group. . 297 Figure 5-15. Vowel production in three speech tasks for the frequent travel group. .... 297
1
1 INTRODUCTION
The primary objective of this dissertation is to provide a descriptive, acoustic
characterization of the heritage Spanish vowel system. Heritage speakers, who are
sometimes referred to as circumstantial or early bilinguals (Valdés, 2005), are a specific
type of bilingual differentiated principally from other bilingual, monolingual, and learner
populations by their 1) early contact with, and acquisition of, a minority language in a
naturalistic context and 2) limited access to formal education in the minority language
until later in life.
Although heritage speaking populations exist in multilingual contexts throughout the
world (e.g., Spanish-Catalan bilinguals in Spain, French-English bilinguals in Canada,
and French-Arabic bilinguals in France), the present investigation focuses on heritage
speakers of Spanish living in the United States. Therefore, for the purpose of this
investigation, a heritage speaker (hereafter HS) of Spanish is defined as a Spanish-
English bilingual who grew up within a Spanish-speaking household and community, and
was thus exposed to the Spanish language from an early age, often from birth (Bolger &
Zapata, 2011; Montrul et al., 2008b; Potowski et al, 2009; Valdés & Geoffrion-Vinci,
1998). The HS of Spanish described in this investigation were raised in the United States
overhearing and speaking Spanish within the home and community with parents,
relatives, and neighbors, but most did not receive any formal literacy education in the
Spanish language until high school or college. Therefore, like monolingual speakers of
Spanish and simultaneous Spanish-English bilinguals, HS acquired the Spanish language
naturalistically from a very early age. Their exposure to and experience with Spanish
during childhood results in their exhibiting advanced communicative and comprehension
2
skills, much like those of monolingual and simultaneous bilingual speakers. In contrast,
however, most HS do not receive formal literacy instruction in Spanish until later in life –
a characteristic they share with L2 learner populations – and are therefore sometimes
described as possessing a “limited ability” in the areas of formal oral and written
discourse (Montrul et al., 2008b).
1.1 Previous linguistic research on heritage populations
The study of the linguistic knowledge of HS of Spanish has received much attention
in the past two decades. Two areas that have garnered considerable attention are the
pedagogy for HS and the morphosyntactic knowledge of HS. The general findings in
these two distinct bodies of literature reveal important differences and similarities
between HS populations and late L2 learners, simultaneous bilinguals, and age-matched
monolingual speakers of Spanish. Research in the field of pedagogy, for example, has
emphasized that because HS acquired Spanish naturalistically during early childhood but
did not receive any explicit instruction during primary school, their instructional needs
are unique. A number of investigations in the fields of heritage and second language
acquisition have focused on 1) testing the effectiveness of instructional methods utilized
in traditional foreign language classrooms, or 2) devising unique instructional strategies
for heritage populations that emphasize the acquisition of the formal oral and written
registers (Kagan, 2005; Lynch, 2003; Montrul et al. 2008; Potowski et al., 2009;
Rothman, 2007). The general findings of this literature indicate that HS benefit most
from communicative methods of language instruction as opposed to form-focused
exercises, even if the gains are not the same as those observed in L2 learner populations
(Potowski et al., 2009).
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Research in the field of morphosyntax has revealed additional differences, but
also some similarities, between HS and late L2 learners in terms of their production and
judgment of certain morphosyntactic structures. Heritage speakers typically outperform
proficiency-matched L2 learners in speech production tasks and more closely
approximate native-like usage of structures such as clitic pronouns and grammatical
gender (Montrul et al., 2008a; Montrul, 2010). In contrast, L2 learners sometimes
outperform HS on written grammaticality judgment tasks by rejecting ungrammatical
structures more frequently and systematically than HS (Montrul et al., 2008a; Montrul et
al., 2008b). Despite the differences, however, HS share certain aspects of acquisition
with L2 learners such as transfer errors from the majority language, lexical extension, and
syntactic calquing (Lynch, 2003). Also similar to L2 learner populations, HS exhibit a
wide-range of variation in their Spanish abilities that is influenced by a number of factors
(Mikulski, 2010; Mrak, 2011). Extralinguistic factors such as Spanish use outside of the
classroom and frequency of travel, for example, have been found to influence HS
performance on morphosyntactic tasks (Mikulski, 2010; Montrul et al., 2008b).
One of the central arguments presented in the morphosyntactic literature is that HS
experience a “benefit” in pronunciation (but not in morphosyntax) as a result of their
early exposure to the Spanish language, resulting in their “sounding” more “native-like”
than those who acquired the language later in life. Interesting, however, is that very few
studies have systematically examined HS pronunciation. Although a considerable body
of literature has investigated early bilingual pronunciation (Flege, 1991; Flege & Eeftig,
1987; Zampini & Green, 2001; Yavas, 2006, among others), only a handful of studies
have examined HS as they are defined here (Au et al., 2008; Knightly et al., 2003; Oh et
4
al., 2008), most of which have focused primarily on the pronunciation of consonants.1
Combined, the results of the investigations focusing on HS and early bilinguals indicates
that their pronunciation resembles that of a native monolingual in some respects, but
may more accurately be defined as a complex, hybrid system of speech sounds that falls
somewhere between that of an L2 learner and a monolingual speaker.
To summarize briefly, the majority of the investigations which specifically examine
HS of Spanish have focused on knowledge and judgment of morphosyntactic structures,
or have attempted to devise unique instructional strategies for this population. That
considerably fewer studies have examined the pronunciation of this specific subtype of
bilingual motivates the need for a closer examination of the HS phonetic/phonological
system. One area that is deserving of further investigation is the vowel system, due in
part to the fact that HS of Spanish must employ two very different vowel systems (i.e.,
English and Spanish) throughout their daily lives. An additional motivating factor is that
although several recent investigations have examined different aspects of Hispanic
English vowels (Fought, 1999; Godiñez & Maddieson, 1985; Konopka & Pierrehumbert,
2008; Roeder, 2010), no study to date has described or analyzed the Spanish vowel
system of heritage Spanish speakers.
1.2 Spanish vowel systems
The Spanish vowel system is traditionally described as a simple, symmetrical, five-
vowel system that is diatopically stable, especially in comparison to English (Hualde,
2005). Based on the assumption of stability and simplicity, considerably fewer acoustic
studies of Spanish vowels have been conducted as compared to studies of Spanish 1 Notable exceptions are Bullock (2009) for heritage prosody, Chang et al. (2009) for heritage Mandarin vowels, and Godson (2003) for heritage Armenian vowels.
5
consonants. Quilis and Esgueva (1983) provided some of the first acoustic descriptions
of Spanish vowels, including baseline acoustic measures which showed the presence of
small differences in vowel quality and duration based on stress context and talker gender,
but the overarching assumption has remained that there is little variability within the
system in general.
In addition to the assumption of cross-dialectal similarity in vowel productions,
traditional descriptions of the Spanish vowel system argue that 1) vowel quality and
duration are fairly unaffected by lexical stress (Delattre, 1969; Hualde, 2005; Quilis &
Esgueva, 1983; but in contrast, Marín Gálvez, 1995) and 2) the Spanish mid vowels
exhibit allophonic variation based on syllable type (Navarro-Tomás, 1918; but in contrast
Morrison, 2004; Servín & Rodríguez, 2001). Unfortunately, our knowledge of Spanish
vowel production and the assumptions about the system are primarily based on analyses
of Peninsular varieties of Spanish and/or vowels produced in highly controlled speech
styles (Bradlow, 1994; Morrison, 2004; Morrison & Escudero, 2007). More recent
studies of non-Peninsular varieties and vowels produced in less-controlled speech styles
suggest that there may be more dialectal and stylistic variation in the Spanish vowel
system than previously believed (Delforge, 2008; O’Rourke, 2010; Martín Butragueño,
2011; Poch-Olivé et al., 2008; Willis, 2005).
Acoustic studies of bilingual vowel suggest that bilingual speakers of Spanish exhibit
a modified system of pronunciation that differs from monolingual norms within the same
dialect region. O’Rourke (2010) and Menke and Face (2010) reported differences in
overall dispersion in distinct populations of Quechua-Spanish and English-Spanish
bilinguals and L2 learners, respectively. Willis (2005) reported that Spanish-English
6
bilinguals in the Southwestern United States produced /u/ farther front, /o/ lower, and /a/
farther front than the same monolingual Spanish vowels described by Quilis and Esgueva
(1983). Finally, both Menke and Face (2010) and Alvord and Rogers (2011) reported
that bilingual speakers in the Southwestern United States and Miami-Cuban bilinguals
exhibited considerable unstressed vowel centralization not attested in monolingual
varieties.
Taken together, the results of the investigations discussed above motivate the need
for further examination of Spanish vowel systems and bilingual Spanish vowel
production. Recent acoustic studies have brought into question some of the basic
assumptions about Spanish vowels, resulting in considerable disagreement among
researchers as to how the Spanish vowel system is organized acoustically and which
linguistic and stylistic factors affect vowel quality and quantity. Heritage speakers, who
are argued to “sound” native, provide the opportunity to test the robustness of the effects
of linguistic and stylistic variables on Spanish vowel production, while at the same time
offering insight into the bilingual vowel system.
1.3 Goals
The literature discussed above motivates the need to further investigate HS
pronunciation as well as Spanish vowel production. Thus, the goals of the present study
are as follows:
1) To contribute to the general body of literature pertaining to Spanish vowels by systematically examining HS vowel production in a number of contexts.
2) To provide a descriptive, acoustic characterization of the heritage Spanish vowel system by:
7
a) Assessing the extent to which HS vowels resemble monolingual Spanish vowels as they are traditionally described in the literature.
b) Taking detailed, acoustic measurements of vowel formants, duration, and calculating the distance of HS vowels from the center of the vowel space.
3) To examine the role (or lack thereof) of lexical stress, syllable type, and speech style on HS vowel production.
4) To investigate if and how individual characteristics such as course level, grammar proficiency, travel abroad, Spanish use, and cultural sensitivity influence HS vowel pronunciation.
In order to achieve these goals, a series of speech elicitation instruments and
questionnaires were designed and administered to a group of HS residing in Chicago, IL.
Through a combination of acoustic and statistical analyses, the present investigation
provides an in-depth understanding of Spanish-English bilingual vowel systems.
1.4 Contributions
The present research study makes several important contributions to the fields of
Spanish phonetics and bilingual speech pronunciation. First, this dissertation contributes
to the general body of literature pertaining to Spanish vowels. Traditional descriptions of
the Spanish vowel system argue for a simple, stable, symmetrical vowel system that
exhibits some variation based on speech style and syllable type, but is fairly unaffected
by lexical stress (Hualde, 2005; Quilis & Esgueva, 1983). Analyzing the relationship
between HS vowel production and the aforementioned variables may test the robustness
of previous claims, and offer important insight into how the Spanish vowel system can
vary.
Secondly, the present investigation provides the first acoustic description and
analysis of heritage Spanish vowels as produced by speakers of (primarily) Mexican
8
descent living in the Midwestern United States. This study therefore offers an important
first glimpse at the vowel system of this population.
Thirdly, this initial examination of HS vowels is a crucial first step in systematically
addressing the assumption that heritage speakers resemble native speakers in terms of
their pronunciation. Future comparisons between monolingual speakers of Spanish will
reveal the extent to which HS approximate native speaker norms, which characteristics
they share with native speakers, and on which dimensions they differ.
In addition, the present investigation lays the foundation for future work comparing
HS pronunciation to L2 speech, as well as to additional regional HS varieties throughout
the United States. Future comparisons with L2 learner populations will permit further
examination of how early exposure to a language during childhood affects vowel
production in adulthood. Comparisons with heritage populations in other regions
throughout the United States may offer insight into if and how regional varieties of
heritage Spanish differ across the country, and how contact with different dialects of
English may influence their pronunciation of Spanish vowels.
Finally, an examination of the extralinguistic factors argued to influence HS
morphosyntactic knowledge and HS and L2 (consonantal) segmental production will
reveal 1) the relationship between these same variables and the pronunciation of vowels,
and 2) similarities and differences between HS and L2 learners in terms of how they
benefit from certain linguistic practices.
To preview the results of this investigation, the statistical analyses revealed that 1)
HS exhibit a unique distribution of vowels within the acoustic space that is not attested in
monolingual varieties, 2) lexical stress and speech style impact the degree of
9
centralization and total duration of vowels, and 3) the HS who speak Spanish and travel
more frequently produce vowels more peripherally (i.e., expanded) than those who report
less usage and travel. The findings offer additional support for the argument that
bilingual speakers exhibit a modified system of pronunciation. The results also suggest
that some of the same activities known to have a positive impact on L2 phonology also
influence HS vowel production.
1.5 Dissertation outline
The remainder of this dissertation is organized as follows. Chapter two provides a
comprehensive review of the literature describing heritage speakers, vowels, and
bilingual pronunciation. The research questions guiding the present study and the
hypotheses are motivated at the end of chapter two. Chapter three describes the
methodology employed in the present study, including the details of the instruments,
participants, data analysis, and statistical analyses employed to analyze the data. The
results of the statistical analyses conducted on the data are described in chapter four. A
discussion of the results is presented in chapter five, and the overall conclusions in
chapter six.
10
2 PREVIOUS LITERATURE
The goal of this chapter is to discuss the previous literature that has relevance to this
dissertation. Section 2.1 defines the population under investigation—heritage speakers—
and describes some of the current findings pertaining to their linguistic knowledge. The
purpose of section 2.2 is to discuss vowel systems, with specific emphasis on Spanish
vowel systems. The contributions of both impressionistic (section 2.2.2) and acoustic
(2.2.3) studies of Spanish vowels will be discussed, and a separate section is devoted to
reviewing the literature on bilingual and contact vowel systems of both Spanish and
English (sections 2.3.1 and 2.3.2, respectively). The final objective of this chapter is to
discuss the connection between language and an individual’s language background and
use, connection with the heritage culture, and cultural sensitivity and pronunciation
(section 2.4). The chapter will conclude with a synthesis of the previous literature and
how it relates to the goals of the present investigation, as well as the research questions
and hypotheses that are guiding this study in section 2.5.
2.1 Heritage speakers
This portion of the chapter will 1) introduce the population of investigation in the
present study, and 2) describe some of the research that has focused on their linguistic
systems. A definition of heritage speakers will be provided, as well as an overview of the
investigations focusing on differences between this population and L2 learners. The
review of the literature pertaining to the fields of morphosyntax and pedagogy is not
exhaustive, but is sufficient to explain some of the most important characteristics of this
population. The final portion of this section discusses studies of bilingual and heritage
11
speaker pronunciation, again presenting the most important findings reported in the work
on early bilingual and heritage language pronunciation and phonology.
2.1.1 Who are heritage speakers, and why should we learn more about them?
The definition of a “heritage speaker” (hereafter HS) presents a wide-range of
variability. This definition can be viewed as a continuum which includes, at one extreme,
those individuals who feel a connection or association with their heritage but do not
speak or understand the heritage language, to those who have advanced comprehension
and oral communication abilities (Mikulski, 2010; Mrak, 2011). Much of the literature
pertaining to HS of Spanish defines this group as consisting of bilingual speakers of
English and Spanish who grew up speaking Spanish in the home and community, but
who were formally educated almost exclusively in English (Bolger & Zapata, 2011;
Potowski et al., 2009; Montrul et al., 2008). HS were raised in Spanish-speaking
households and acquired the Spanish language naturalistically at a very early age, often
from birth, and often simultaneously with English (Bolger & Zapata, 2011). The early
exposure to Spanish results in their exhibiting communicative and comprehensive
proficiency in the Spanish language even though they often do not receive formal
education in the language until high school or college (Montrul & Bowles, 2010). The
majority language, in this case English, however, is the typical language of social
interaction outside of the home and community with peers and siblings (Lynch, 2003).
Given that HS exhibit variability in use of the heritage language and also differ in
terms of the quantity of input they receive in the home, many researchers have argued
that the HS linguistic system is “incomplete,” “deficient,” or “abbreviated” when
compared to that of a monolingual (Bolger & Zapata, 2011; Potowski et al., 2009;
12
Montrul et al., 2008; Montrul, 2010). In addition, Kagan (2005) argues that HS differ
from late L2 learners (i.e., those who began learning a second language after puberty), as
well as from monolingual native speakers of the heritage language, and should be treated
differently from these populations in terms of instruction. These arguments have
prompted a considerable amount of research in the separate areas of morphosyntax and
pedagogy that examines how HS, L2 learners, and monolinguals differ with respect to 1)
their morphosyntactic knowledge and 2) their respective pedagogical needs.
The majority of the literature pertaining to HS has examined HS knowledge and
judgments of different grammatical structures and analyzed how their performance on
oral and written tasks compares to that of late L2 learners. Although an exhaustive
review of the morphosyntactic literature is not possible here, several notable studies
describe the similarities and differences between learner and heritage populations. The
assumption present in much of the literature is that early exposure to the Spanish
language results in HS benefitting in the domain of pronunciation, but not, or not as
much, in the morphosyntactic, syntactic, or lexical domains (Montrul et al., 2008).
A number of investigations conducted by Montrul (2005; 2010) and Montrul,
Foote, and Perpiñán (2008a; 2008b) seem to confirm that HS do not exhibit superior
grammatical knowledge or performance when compared to L2 learners, but subtle
differences do exist between the groups based on the type of task (oral vs. written) and
especially once proficiency level is taken into account. Montrul (2005), for example,
examined HS, L2 learner, and monolingual judgments of the syntax and semantics of
unaccusative and unergative verbs in Spanish. The HS and L2 learners were grouped
into low, intermediate, and advanced levels based on their scores on a grammar
13
proficiency test. The general results in this study show that L2 learners and HS at
advanced levels are very knowledgeable of the syntax of unaccusativity in Spanish, and
that they show similar patterns in terms of acceptability ratings. The HS at low levels,
however, differed from low-level L2 learners in their acceptance of the semantic reading
of unaccusative and unergative verbs. Whereas the HS showed variable patterns of
acceptance that were less robust than the intermediate and advanced groups, they
outperformed the low level L2 learners who showed no knowledge of the semantic
differences between these verb types. Thus, Montrul’s (2005) results suggest that, while
L2 learners and HS are similar with respect to their syntactic knowledge and judgments,
at the low levels of proficiency, HS early exposure to language may result in a slight
benefit in semantic knowledge.
An additional study by Montrul et al. (2008a) analyzed L2 learner and HS
knowledge of grammatical gender in Spanish. Late English-Spanish bilinguals (L2
learners), early Spanish-English bilinguals (heritage speakers), and monolingual control
subjects completed a grammar proficiency test, two written tasks testing knowledge of
grammatical gender, and an oral production task. The proficiency tests revealed that the
HS and L2 learners did not differ statistically with respect to the performance on this test,
but that they scored significantly lower than the monolingual controls. The results from
the written tasks on gender agreement indicated that L2 learners performed significantly
better than the HS and made fewer, more systematic errors. In contrast, the HS exhibited
fewer errors in the speech production task when compared to the L2 learner groups. The
results of this investigation support the argument that early language exposure does not
result in significant gains in morphosyntactic knowledge, as the HS and L2 learners
14
exhibited comparable proficiency scores and showed similar error patterns. The benefit
was observed in production, however, with the HS producing fewer agreement errors in
the oral task.
Montrul (2010) investigated L2 and HS knowledge of clitics, clitic left
dislocation, and differential object marking. Heritage speakers and L2 learners
participated in production tasks and grammaticality judgments tasks containing these
structures. In terms of production, the HS produced more clitics, behaving similarly to
the monolingual Spanish speakers, whereas the L2 learners produced more NP’s—
evidencing greater transfer effects from English. Heritage speakers also approximated
the native speaker norm in their judgment of sentences containing clitic left dislocation,
and outperformed the L2 learners who assigned lower acceptability ratings to these
sentences. The differences between L2 learners and HS were most notable in the
differential object marking tasks. Although both groups had difficulty marking animate
direct objects in the production tasks, the HS outperformed the L2 learners. In the
grammaticality judgment task, however, the L2 learners were less accepting of
ungrammatical sentences than HS. This result confirms previous findings that HS tend to
perform better on oral and production tasks than L2 learners, but that learners often
outperform HS on written tasks. Overall, this study shows that both groups of bilinguals
have difficulty with object markers, but they manifest themselves differently in each
population.
In a related study, Montrul et al. (2008b) investigated the knowledge of Wh-
movement in Spanish by the same participants examined in their 2008(a) study on
grammatical gender. Their initial analysis of language proficiency and grammaticality
15
judgments of all sentences types indicated that the early (HS) and late (L2) bilinguals
showed no significant differences in proficiency or in judgments. They then divided the
participants into high, intermediate, and low proficiency groups based on the scores from
the proficiency test, and examined performance on all of the different sentence types
separately. This reexamination of the grammaticality judgment task showed that mid and
high level HS accepted ungrammatical sentences without complementizers more than the
mid and high level L2 learners. The low level HS and late bilinguals showed even higher
acceptability ratings of these ungrammatical sentences, but the difference between these
two groups at this level was not statistically different. A final step in this investigation
examined the individual response patterns of the participants, grouping them according to
their preferences. These results showed that HS exhibited patterns that were more similar
to the native speakers than those of the late L2 learners. The results of this investigation
are thus somewhat contradictory. In terms of proficiency, overall judgments, and
acceptance of ungrammatical Spanish sentences without complementizers, HS and L2
learners appear very similar. These results support the argument that early exposure to
the language does not result in a benefit in knowledge of the syntactic structures tested.
On the other hand, when response patterns were analyzed, the HS exhibited patterns that
were more similar (although not statistically) to those of native monolinguals than did the
L2 learners. Taken together, the findings from this study provide evidence that HS and
L2 learners are similar in terms of their grammatical knowledge in some respects, but
differ in others.
The results of the type obtained in the four previous studies mentioned above lead
to several, sometimes contradictory, conclusions about the differences between HS and
16
L2 learners and how overhearing the language during childhood affects grammatical
knowledge and performance. In terms of language proficiency, HS and L2 learners, and
especially those at the advanced levels, perform similarly on morphosyntactic and
syntactic tasks, suggesting little benefit in these domains as a consequence of learning
Spanish early. Both populations have been argued to exhibit similar errors and evidence
of transfer effects from the dominant language, but these “errors” may manifest
themselves in different ways. Subtle differences do exist between these groups of
bilinguals, however, in that HS perform better on oral tasks, L2 on written tasks.
Differences in grammaticality judgments exist, but are most observable in the lowest
level of learners. Finally, analysis of overall response patterns and consistency of
errors/judgments suggests that HS more closely mimic the monolingual control patterns
than do the L2 learners.
In addition to the studies pertaining to HS morphosyntactic knowledge and
grammaticality judgments, research has also questioned the pedagogical needs and types
of language instruction that are most beneficial to them. Kagan (2005) argues strongly
that HS (or in her terms, HLL’s) are neither native monolingual speakers nor L2 learners
and thus need to be treated separately from those two groups. In particular she argues
that HS “1) cannot be dismissed as native speakers who need no instruction, 2) do not
need to be placed in beginning-level language classes, 3) can be tracked and placed
according to their background, and 4) need a curriculum with a structure and a set of
materials that differ considerably from those intended for foreign language students” (p.
216). With respect to her fourth point, she specifically argues that classical literature,
17
film, and poetry, should be included in the curriculum, and that a cross-cultural and
comparative approach be introduced to facilitate higher-level language skills.
Valdés (2005) is in accordance with Kagan (2005), citing even greater distinctions
within HS populations. She argues that not only should instructional strategies differ for
HS and L2 learners, but that also the stage in the HS language continuum in which an
individual falls should determine the type of language instruction he or she needs. For
example, HS who failed to acquire a structure as part of the L1 may benefit from form-
focused language instruction similar to that employed in an L2 classroom. In contrast, in
cases of attrition in which a form has already been acquired but lost, focused instruction
may be inappropriate. The individual who falls into this category may benefit more from
the type of input and interaction more akin to a monolingual linguistic interaction, as
opposed to traditional grammar exercises presented to L2 learners.
As with the investigations pertaining to morphosyntax, an exhaustive review of
pedagogical studies will not be presented here. One study in particular conducted by
Potowski, Jegerski, and Morgan-Short (2009), however, exemplifies how L2 learners in a
traditional foreign language classroom and HS differ in terms of how they benefit from
overt language instruction. The primary goal of their investigation was to examine the
differences and similarities between HS and L2 learners’ acquisition of the subjunctive
mood via two different types of language instruction: processing instruction and
traditional instruction. Their goal was to determine if HS would benefit from overt
grammar instruction of this structure in the same or different way as late L2 learners
enrolled in a traditional language classroom. One hundred and one HS and 22 L2
learners completed a pretest and a posttest, and completed 9 different tasks (either
18
processing instruction or traditional instruction, depending on the group). Ten control
subjects who did not receive treatment were also included. Overall, the results of this
investigation showed that heritage speakers also benefit from overt language instruction
of grammatical structures, but that they differed in certain ways from the L2 learners.
Although the HS and L2 learners both showed improvement in the posttest for the
interpretation and production tasks, only the L2 learners showed improvement in the
grammaticality judgment task. This improvement, coupled with the fact that L2 learners
actually outperformed the HS on the post-test, indicated that HS do not benefit from these
types of language instruction in the same way that L2 learners do. The authors explain
that this difference may be due in part to the fact that L2 learners are more accustomed to
structured grammar activities. In contrast, the HS who were enrolled in upper-level
university courses were more accustomed to writing and production activities. Given a
statistical complication, it was not possible to determine which form of instruction was
significantly more beneficial for either group. The overall conclusion, however, is that
HS do benefit from overt language instruction, but the effect many not be as pronounced
for this population when compared to L2 learner populations. This conclusion supports
the need for different types of instructional strategies for HS of Spanish.
Taken together, the research presented above portrays heritage speakers as a
unique population. In some ways, they share characteristics with late L2 learners who
acquired Spanish in a traditional foreign language classroom such as, overgeneralization
and simplification of variable structures, lexical extension, and syntactic calquing
(Lynch, 2003). In other respects, HS differ from L2 learners in terms of the performance
on oral production tasks and their ability to recognize fine-grained semantic differences
19
between different syntactic and morphosyntactic structures (Montrul, 2005; Montrul et
al., 2008a, 2008b). In this way, HS often more closely resemble monolingual native
speakers of Spanish when compared to age-matched L2 learners who acquired the
language later in life. Additional research in the field of language pedagogy supports the
need for HS to be treated differently from L2 learners, indicating that they do not benefit
in the same way from traditional forms of grammar instruction as the late L2 learner does
(Potowski, et. al, 2009). Lynch (2003:11) specifically argues for content-based,
communicative approaches in HS language classrooms, arguing that their language has
been “dialogic, discursive and absolutely contextual from the beginning.”
One other crucial difference between HS and L2 learners is that for the HS,
language is often a means of establishing, maintaining, or expressing identity and a
connection with the heritage culture. Further explanation and examination of the HS
identity as expressed through language will be presented in section 2.4.
2.1.2 Early bilingual and heritage pronunciation
Although very few studies have examined the pronunciation of heritage speaker
populations as they have been defined here, a considerable body of literature has
examined bilingual pronunciation, as well as the pronunciation of early and late bilingual
populations. These studies have revealed several important characteristics of bilingual
speakers and the factors that influence the pronunciation of the L2 and the L1. The first
important finding is that bilingual speakers’ pronunciation often approximates the native
speaker norm, but their production is not identical to that of a monolingual native (Yavas,
1996; Zampini & Green, 2001). Several studies analyzing the VOT of /ptk/ and /bdg/ in
English and Spanish, for example, indicated that bilinguals produced these sounds with
20
intermediate values that fell somewhere between those of fluent monolinguals of English
and Spanish (Flege & Eefting, 1987, 1988; Yavas, 1996). The intermediate values may
be the result of a bi-directional influence of the L1 and L2 on speech production, lending
evidence to the notion that the bilingual has a modified system of pronunciation and not
two completely separate systems (Flege & Eefting, 1987; Zampini & Green, 2001).
Finally, factors such as the age of learning a second language and the age of arrival to a
country in which the L2 is spoken also influenced the perception of foreign accented-ness
in speech. Bilinguals who acquired a language later in life or arrived to the country in
which the L2 was spoken as adults were rated as sounding less native than those who
learned their L2 as children or arrived in the country as youngsters (Flege et al., 1995;
Munro et al., 1996).
As introduced earlier in this chapter, one of the main claims present throughout
the literature is that as a result of their early exposure to the Spanish language, HS
experience a benefit in the phonological domain and in pronunciation but not necessarily
in morphosyntax (Knightly et al., 2003; Montrul et al., 2008a). In order to test this
assumption, Knightly, Jun, Oh, and Au (2003) conducted a series of experiments
consisting of acoustic analysis as well as grammaticality judgment and written
morphosyntactic tasks.2 In their 2003 investigation, Knightly et al. examined the speech
2 Although not discussed in detail in the text, two additional studies were conducted by this group of researchers that preceded the investigations mentioned here. Au et al. (2002) was a precursor to Knightly et al. (2003). The results of this study were nearly identical to those reported in Knightly et. al (2003): overhearers produced /ptkbdg/ in a more native-like manner than late L2 learners, and there was no statistical difference in morphosyntactic knowledge between the childhood overhearers and the L2 learners. This first study in the series showed, however, that merely overhearing Spanish in childhood is sufficient to provide pronunciation benefits. An additional study by Oh, Jun, Knightly, and Au (2003) examined childhood speakers, childhood overhearers, and novice learners of Korean. These results again showed that childhood speakers benefitted in their pronunciation of VOT, their perception of phonemic contrasts, and had higher accent ratings than overhearers and learners. That the same effects reported for Korean were
21
production and grammatical knowledge of 15 Spanish-English bilinguals (native speakers
of Spanish), fifteen late-learners of Spanish who overheard Spanish during childhood but
were not schooled formally in Spanish until adolescence (childhood overhearers), and
fifteen late Spanish learners who had no exposure to Spanish until high school or college
(“typical” late L2 learners).3 The three groups of Spanish speakers participated in several
oral production tasks (i.e., carrier phrase task that examined VOT, retelling of the Frog
Story), as well as several morphosyntactic tasks that examined grammaticality judgments,
the construction of NP’s with gender and number agreement, and a VP completion task.
The results of the analyses of speech production tasks indicated that childhood
overhearers exhibited shorter VOT values for /ptk/ (i.e., more “Spanish-like”) than the
late L2 learners. These differences were particularly robust in word-initial position.
With respect to voicing, the overhearers produced /bdg/ with voicing characteristics that
were intermediate to the native controls and the L2 learners, but the differences were not
statistically significant. Lenition of /b/ and /g/ also differed between the overhearers and
the L2 learners, with the overhearers outperforming the learners with respect to their
pronunciation of /b/, but the reverse was true for the pronunciation of /g/. Native-ness
ratings of the Frog stories revealed that overhearers were rated as more “native-
sounding” than L2 learners, but less so than the native speakers. Finally, the results of
the morphosyntactic components of the experiment revealed no significant differences in
grammaticality judgments or performance between the overhearers and the L2 learners.
corroborated with Spanish in Au et al. (2008), providing further evidence of the benefits of not only childhood overhearing, but more importantly of childhood speaking. 3 The term “typical” is used by Knightly et al. to describe an L2 learner who acquired Spanish in a traditional foreign language classroom setting. I want to clarify that the word “typical” refers to the type of instruction they received, and not that any learner can be classified with such a term given the wide range of variation observed in L2 learner populations.
22
The results of this investigation lend evidence to the argument that overhearing a
language during childhood results in more native-like pronunciation, but that the same
benefit is not observed in other (i.e., morphosyntactic) domains.
Au, Oh, Knightly, Jun, and Romo (2008) conducted a similar study that not only
examined the production and grammatical knowledge of childhood overhearers, but
included childhood speakers of Spanish as well. These two groups, overhearers and
speakers, were then compared to late L2 learners and native speaker controls in order to
test if speaking, as opposed to simply overhearing, a language during childhood results in
greater gains in pronunciation and grammatical competency. Ten childhood speakers, 20
childhood overhearers, 39 L2 learners who did not speak or overhear Spanish during
childhood, and 25 native speakers of Spanish took part in the experiment. All
participants were first tested on their production and comprehension of slang by
translating orally a series of English slang phrases into Spanish and Spanish slang phrases
into English. The responses were then compared to a list of acceptable translations
compiled by native Spanish speakers from various dialect regions. The results of this
first task showed that native speakers had the highest translation accuracy, followed by
the childhood speakers, the overhearers, and the L2 learners with the littlest knowledge of
slang. The other instruments utilized in this study are identical to those used in Knightly
et al. (2003): production of sentences in a carrier phrase to test VOT, retelling of The
Frog Story, a noun phrase production, a verb phrase production, and a grammaticality
judgment task. They also included a task which examined the perception and production
of sentences in noise. Like the results of Knightly et al. (2003), the findings of this
investigation also showed that early exposure to Spanish during childhood resulted in
23
more native-like pronunciation. The crucial difference, however, is that the speakers
tended to outperform the overhearers in terms of their native-ness ratings and their
repetition and perception of sentences in noise. In addition, the childhood speakers were
found to produce narratives that were more grammatically well-formed and were better at
detecting errors in ill-formed grammatical constructions. Overall they conclude that
although overhearing a minority language during childhood has a positive impact on
pronunciation in adulthood, actually speaking the language during childhood provides
additional gains.
Au et al.’s (2008) research concludes with a discussion of which other factors
may have resulted in the childhood speakers outperforming the other two non-native
groups. The estimated number of hours that each of the groups was exposed to Spanish
was found to correlate with the well-formed-ness of production in the narrative task: the
more exposure, the more well-formed the constructions were in the narrative. An
analysis of daily Spanish use and motivation to speak Spanish was also conducted. These
analyses revealed there were no differences between groups in terms of their daily use of
Spanish and motivation to speak Spanish outside of the classroom, and no significant
correlations between this usage and their pronunciation and grammatical knowledge.
There was some suggestion that motivation to learn and maintain their Spanish abilities
may affect native-ness ratings (pronunciation), but the statistics revealed no reliable
differences between the groups. Even though none of the extralinguistic factors
examined in the subsequent analyses correlated with or explained the differences between
overhears and speakers, Au et al. (2008) argue that quantity of input, Spanish use, and
24
motivation may have a significant impact on pronunciation and grammatical knowledge
if a larger sample were to be analyzed.
In addition to the research conducted by Au et al. (2008), Knightly et al. (2003),
three other notable acoustic studies on heritage language pronunciation have been
conducted, although none of them examined heritage Spanish and only two of them
examined vowels. Bullock (2009) for example, examined the patterns of intonation
exhibited by two heritage speakers of French in Frenchville, Pennsylvania. In particular
she examined penultimate prominence, focus via prominence in situ, and the prosody of
left dislocation. A series of acoustic analyses of the intonation contours produced by
these speakers in French indicated that their pitch accents and use of tonal contours
differed from the patterns generally attested for monolingual varieties of French, but were
similar to those of English. It was argued that their use of intonation as a means to focus
or emphasize certain structures within a phrase was most likely the result of long-term
contact with English in the area, but interestingly, the syntactic characteristics typically
employed to signal information structure (left dislocation and clefts) were still present in
their speech. The integration of English-like focus and prominence strategies via
intonation was determined to be an additional recourse for these speakers. Their contact
variety thus maintained many of the characteristics of the heritage language system, but
also incorporated elements of the majority language. The result was a unique variety
which provided additional opportunities and strategies to express prominence in French.
Chang, Haynes, Yao, and Rhodes (2009) analyzed the vowel pronunciation and
laryngeal characteristics (VOT) of Mandarin native speakers, heritage speakers of
Mandarin, and native English learners of Mandarin. They examined the acoustic
25
characteristics of the rounded vowels /u/, /ou/, and /y/ in English and Chinese. The
vowel articulations and words containing the words with distinct laryngeal categories
were obtained from a list of read phrases in English and Mandarin. The acoustic analyses
of F1, F2, and F3 of these vowels indicated several important differences between the
native, heritage, and learner groups.4 Native speakers of Mandarin produced both
Mandarin and English /u/ with the lowest F2 values (i.e., farther back), the L1 English-
dominant learners of Mandarin produced /u/ with the highest F2 values (i.e., farther
front), and the heritage speakers of Mandarin produced /u/ in both languages with
intermediate values that fell between the productions of the natives and learners. Chang
et al. suggest that this pattern indicates that the native language of the participants (i.e.,
native Mandarin vs. native English L2 learners of Mandarin) influenced the production of
the L2 sounds: Native Mandarin speakers produced English /u/ in a manner more similar
to Chinese /u/, whereas the native English-speaking L2 learners of Mandarin produced
Chinese /u/ with values more similar to English /u/. The heritage speakers were found to
produce /u/ vowels in both languages that were closer to the native productions. A nearly
identical pattern was observed for the Mandarin vowel /ou/, with native Mandarin
speakers producing the /ou/ with the lowest F2 value, the learners the highest F2 value,
and the HS clustering between those values. This same difference between groups was
not observed, however, for the production of the Mandarin rounded vowel /y/.
The results of this experiment revealed two very important conclusions that are
relevant to the present investigation. The first is that the three groups of speakers
produced both Mandarin and English vowels that differed according to distribution
4 Although the F3 value was measured in Chang et al.’s (2009) study, they do not report any analyses conducted on the third formant.
26
within the space. That is, each group’s vowel space was distinct in each language. A
second important finding is that HS of Mandarin produced the high /u/ and the mid /ou/
with values that were intermediate to those of the natives and the learners. They were
also found to produce vowels that were closer to the native speaker norms when
compared to the production of the L2 learners, and maintained the greatest difference
between the categories in the two languages.
The second experiment in this study examined each speaker’s VOT of English
voiced /bdg/, voiceless /ptk/, Mandarin unaspirated /ptk/ and Mandarin aspirated /pʰ, tʰ,
kʰ/. The results of the analyses of VOT for these three speaker groups were less robust
than the findings of vowels, but still revealed important differences between HS of
Mandarin and L2 learners. The most important finding from the second analysis was that
Mandarin native speakers and HS of Mandarin were able to produce differences between
the Mandarin unaspirated and English voiceless stops, but the L2 learners were not. The
authors also report that there was a correlation between speaker rank (i.e., use of
Mandarin) and these productions. This significant correlation indicated that as a
participant’s experience with Mandarin Chinese increased, they exhibit greater degrees of
aspiration of the Mandarin aspirated stops. Taking into consideration the findings of
these two experiments within the study, HS of Mandarin exhibit a modified or
intermediate system of vowel pronunciation. The pronunciation of the aspirated
Mandarin stops was also affected by level of experience with the language, such that
more experience resulted in greater segmental production accuracy.
27
The only other study to date to examine the vowel pronunciation of heritage
speakers was conducted by Godson (2003) for Western-Armenian.5 The goal of this
study was to examine if the onset of acquisition of English (early childhood or adulthood)
would affect the pronunciation of Armenian vowels. The participants were two groups of
bilingual speakers of Armenian and English living in Southern California, and one native
monolingual of Armenian. Eight participants were Armenian-English bilinguals who
began acquiring English before the age of 8 (“interrupted acquirers” of Armenian), ten
were Armenian-English bilinguals who acquired English as adults (“uninterrupted
acquirers” of Armenian), and one speaker served as a monolingual Armenian control.
All participants were female, and all except for the monolingual control indicated that
they were either English dominant or considered themselves to be bilingual. The vowel
production of Armenian vowels was conducted using a carrier phrase task. The vowels
under investigation were embedded within the words used within the task. The vowel
productions were later analyzed acoustically by measuring the first four formants at the
steady-state of each vowel. In order to assess the potential influence of English on
Armenian vowel production of the two groups of bilinguals, formant values of California
English obtained from a previous study were used for comparison.
The results of the acoustic and statistical analysis revealed that the two bilingual
groups (“interrupted” Armenian bilinguals and “uninterrupted” Armenian bilinguals)
differed in terms of the production and acoustic distribution of the vowels /i/, /ɛ/, and /a/.
The uninterrupted bilinguals who had acquired English later in life produced these
vowels that were closer to the Western-Armenian baseline, whereas those bilinguals who
5 To the best of my knowledge, there are no other acoustic studies of Spanish vowels produced by HS from the United States, as the population is defined here. For heritage Spanish vowel perception, see Boomershine (2011). For Spanish-Catalan bilingual vowel production, see Amengual (2011).
28
learned English earlier in life and thus their acquisition of Armenian was interrupted,
more closely approximated the English measures. The production of the /a/ was found to
be farther front for the both groups of bilingual speakers when compared to both
monolingual baselines. The production of the back vowels /o/ and /u/ did not differ
statistically between the two bilingual groups, but both groups productions differed
considerably from the baseline measures, and especially from the English baseline
measure. This difference was attributed to the fact that Armenian back vowels are
rounded, but that previous research suggests that California back vowels are often
unrounded. The distinction in back vowel pronunciation between the monolingual
English variety and the bilingual varieties suggest that bilinguals resisted integrating this
characteristic of English into their Western Armenian pronunciation. Overall, this
investigation showed that the uninterrupted Armenian bilinguals (i.e., those who learned
English later in life) produced vowels that resembled the monolingual baseline for this
language, but were also distinct from the interrupted bilinguals who learned English by
age 8. This result is consistent with previous accounts of a modified vowel system for
heritage speakers of a language. The influence of the second language was not consistent
across all vowels, however. The research concludes by arguing that theories of bilingual
speech production that argue for consistent influence of the L2 across the board are too
general in nature.
In summary, the research presented in this section portrays HS as a population
that is neither a monolingual nor a language learner in the most traditional sense.
Although there is much variation within heritage populations, HS generally exhibit
communicative proficiency in the heritage language, even if their formal grammatical
29
knowledge is incomplete. They share some characteristics with L2 learners, but often
outperform later learners in their ability to detect fine-grained differences in meaning and
structure. Their pronunciation is often judged to be superior to, at least more native-like
than, that of L2 learners, but HS pronunciation is not identical to that of a monolingual
native either. The acoustic studies of speech production of HS and early bilinguals have
shown that their system can often be described as intermediate, falling somewhere
between that of a native and an L2 learner.
This dissertation focuses primarily on describing and exploring the phonological
system of HS of Spanish with specific reference to their Spanish vowel system. The two
studies conducted by Chang et al. (2009) and Godson (2003) indicate that HS of
Mandarin and Armenian, respectively, show patterns of vowel production that differ from
established monolingual norms in both languages. While the present study does not
directly compare the production of HS vowels to monolingual speakers who had
completed the same set of elicitation tasks, it will comment on the nature of the HS vowel
organization and dispersion, and how these patterns compare to traditional descriptions of
the Spanish vowel system. More information pertaining to vowels, and Spanish vowel
systems in particular, is presented next in section 2.2.
2.2 Vowel systems
This portion of the chapter introduces the basic articulatory and acoustic qualities
of vowels, discusses previous research on Spanish monolingual vowel systems, and
comments upon additional research of Spanish bilingual vowel systems and heritage
English vowel systems.
30
2.2.1 General properties of vowels
Unlike consonants which are produced with a blockage or constriction in the
vocal tract that impedes the airflow, vowels are a class of speech sounds that are
produced with a relatively unobstructed airway (Ladefoged, 2001). In Spanish, vowels
are classified as high, mid, or low in terms of their height, and front, central, and back in
terms of their location along the front-back continuum. Some introductory Spanish
textbooks, such as Hualde (2005), suggest that the height and backness of vowels
correspond to the position of the tongue body in the mouth when it produces each vowel,
such that “front” vowels are produced with a fronted tongue position and “back” vowels
with a retracted tongue position. Table 2-1 represents the distribution of the five Spanish
vowels as they are typically presented in introductory textbooks.
Table 2-1
Spanish vowel system based on articulatory parameters
front central back
high i
u mid e
o
low
a
Considerable research in the UCLA Phonetics Laboratory, however, has indicated
that vowels are more accurately classified by taking into account their acoustic properties
and not articulatory parameters (Ladefoged, 1980). The location of the constriction in the
mouth and the resulting size and shape of the vocal cavity result in each vowel being
characterized by its own set of resonant frequencies (Rosner & Pickering, 1994). These
resonant frequencies, known as formants, are characteristic overtones that distinguish
each vowel. Generally speaking, the first three formants are sufficient to describe a
31
vowel’s height, backness, and rounding. The first formant (hereafter F1) is the lowest
resonant frequency and can be equated with the vowel’s height. There is an inverse
relationship between vowel height and F1 frequency, such that low vowels, such as /a/,
have higher F1 frequencies, and high vowels such as /i/ have low F1 frequencies. The
second formant frequency (F2) is correlated with the position of the vowel along the
front-back continuum. Vowels that are categorized as “front” (i.e., palatal, such as /i/)
have higher F2 frequencies than those that are produced with a constriction farther back
(i.e., velar, such as /u/) in the oral cavity. The third formant (F3) is an important correlate
of rounding, as well as r-colored vowels in American English. In Spanish, the two back
vowels /o/ and /u/ are claimed to be redundantly rounded (Hualde, 2005), but as this
rounding is only found in these two Spanish vowels and is redundant with backness, the
F3 is often not analyzed. The third formant is of particular interest in languages like
French that have front rounded vowels.6
In order to better understand the organization and distribution of vowels within
the acoustic space, Figure 2-1 below is a reproduction of the formant values obtained in
an acoustic study of Spanish vowels by Quilis and Esgueva (1983). The values of the
first formant frequency (F1) are presented along the y-axis, and the values for the second
formant frequency (F2) are located on the x-axis.
6 For further reading on the acoustic and articulatory properties of vowels see Ladefoged (1980; 2001; 2003; 2005), Johnson (2003); for Spanish vowel systems, see Hualde (2005).
32
Figure 2-1. Figure of formant values reproduced from Quilis and Esgueva (1983). These values are based off of the F1 and F2 frequency of sixteen male speakers of varying Spanish dialects.
There are several challenges in analyzing the acoustic properties of vowels. The
first is that vowels are highly context sensitive, and their formant frequencies can be
affected substantially based on their immediate consonantal context. The seminal study
by Stevens and House (1963) analyzed the effects of different consonantal contexts on
the formant frequencies of either American English vowels. They first examined the
differences between vowel formants when the vowel was produced in an isolated context
versus when it was produced in a “null” context involving the frame /hVd/ (i.e., “heed,”
“hid,” “had,” etc.). They found that there were no significant differences in formant
values of vowels produced in the isolated and null contexts. For this reason, many
analyses of English vowels often analyze the productions within the hVd consonantal
frame.
The results of their analyses of vowel formants in other consonantal contexts were
very different. They analyzed the production of the same eight English vowels (/i I ε æ ɑ
/i/
/e/
/a/
/o/
/u/
200
300
400
500
600
700
5001000150020002500
F1 H
z
F2 Hz
Spanish formant values (Quilis & Esgueva,1983)
33
ʊ ʌ/) in nonsense words that began with the unstressed syllable /hǝ/ followed by a
stressed syllable with identical consonants on either side of the target vowel (e.g., /hǝbIb/,
/hǝbæb/). The consonants examined were /p b f v θ ð s z t d č ǰ k g/. The results of their
analyses indicated that consonantal context resulted in formant values and patterns of
movement that were different from the isolated and null context vowel formants.
Although the average shifts in F1 were minimal for all vowels, the effect of context on F2
was substantial and dependent upon the consonant and the vowel in question. They
argued that the main trend was for the F2 to of the vowel to shift away from its value in
the null context towards a more centralized position. This means that for the front
vowels, the F2 tended to shift downward (i.e., farther back), and for the back vowels, the
F2 tended to shift upward (i.e., farther front). The front vowels showed the greatest
changes (i.e., greatest lowering of F2) when the surrounding consonants were postdental
or labial and the least effect when in contact with velars. For the back vowels, the
postdental consonants resulted in the largest shift upward of F2, whereas labials had little
effect. They argued that these changes in formant values were the result of how far the
articulators had to move from the consonant to the vowel and then back to the consonant.
The distance and amount of movement resulted in distinct formant values when
compared to a null context.
Stevens and House also analyzed the effect of manner of articulation and voicing
characteristics on the formant values, again describing differences in formant values
based on the characteristics of the consonantal context. These results revealed that when
the surrounding consonants were voiced, the F1 was higher than when the surrounding
consonant was voiceless. Along the F2 dimension, the front vowels showed higher F2
34
values when in contact with voiced consonants than when in contact with voiceless
consonants. The manner of articulation also affected the F2 values of vowels but differed
for front and back vowels. The front vowels /I, ε/ exhibited higher F2 values for stops as
compared to fricatives. Higher F2 values for fricative contexts were observed for the
back vowels when compared to the formant values produced in stop contexts. Overall,
this investigation showed that vowels were affected by the place, manner, and voicing of
the surrounding consonantal contexts. Most studies of monophthong vowels take
formant measurements at the center of the vowel, or try to identify a steady state portion
(Martínez-Celdrán, 1995; Morrison, 2004; Willis, 2005). This helps avoid the influence
of the context and ensures that measurements are not taken at the formant transitions.
Stevens and House’s work, showed, however, that even when the measurements of the
formants were taken at a steady-state midpoint, contextual and coarticulatory effects were
observed.
In addition to coarticulatory effects caused by surrounding consonants, several
other factors need to be considered when analyzing vowels. Although not as relevant to
the current investigation as consonantal context, factors such as vocal tract length,
gender, and regional variety also influence the formant frequencies of vowels. In terms
of vocal tract length, long vocal tracts result in lower formant values, and shorter vocal
tracts result in higher formant values (Rosner & Pickering, 1994). Vocal tract length
varies by age and gender, such that men, who typically have longer vocal tracts, tend to
produce vowels at lower frequency ranges than those of women, and subsequently
children (Hillenbrand et al., 1995; Peterson & Barney, 1952; Rosner & Pickering, 1994).
The differences in vocal tract size often result in the appearance of women having a more
35
expanded vowel space, or producing vowels in more peripheral locations than men
(Rosner & Pickering, 1994). There is some suggestion that the differences in vowel
production observed for males and females may be due in part to sociolinguistic factors
or conscious efforts made by females to modify their vowel articulations. Several studies
argue that women exhibit a wider acoustic space than men either by consciously
modifying the constriction size of their vowels (Goldstein, 1980) or as an “expressive
posture which is socially more appropriate for one sex or the other” (Labov, 1972, p.
304). Despite these claims, Rosner and Pickering conclude that the differences in
formant frequencies are most likely due to anatomical differences.
One final factor which is known to influence vowel formant frequencies deals
with regional variety. It is widely accepted that varieties of American English exhibit
substantial patterns of variation in vowel production based on geographic region (Clopper
et al., 2005; Thomas, 2001). Thus, English speakers from the areas such as Wisconsin
differ greatly from those speakers in the American south with respect to how they
produce certain vowels. For Spanish, however, this regional variation is argued to be
virtually non-existent. Hualde (2005, p. 128) argues that “vowel qualities are
remarkably stable among Spanish dialects. There is nothing like the differences in vowel
quality that we find across geographical and social varieties of English. This is in no
doubt due to the simplicity and symmetry of the system.” He continues on to argue that
the majority of the dialectal variation observed in Spanish tends to occur in the
pronunciation of consonants and not vowels. An acoustic investigation of Peninsular and
Peruvian vowels by Morrison and Escudero (2007) seems to confirm the stability in
vowel pronunciation across Spanish dialects, in that the only vowel that was found to
36
differ across the two dialects was the /o/. Thus, although some languages are argued to
exhibit considerable differences in vowel pronunciation based on geography, Spanish is
argued to not be one of them. Nonetheless, it is important to consider the potential for
variation in vowel production based on geographic region, as few comparative
investigations of Spanish vowel pronunciation have been conducted to date.
To summarize this section, the main acoustic correlates of vowels that will be
discussed in this dissertation are the first (F1) and second (F2) formant frequencies.
These frequencies are associated with vowel height and vowel backness respectively.
Vowels are also highly context sensitive, and the surrounding sounds are known to
influence its acoustic characteristics and location within the acoustic space. Finally,
factors such as vocal tract length, gender, and dialect can influence vowel production.
The same vowel produced by a male speaker and a female speaker will most likely be
characterized by very different formant values. In addition, speakers from different
regions may also pronounce vowels differently, although this is argued to be less
prevalent in the regional varieties of Spanish. The next two sections, 2.2.2 and 2.2.3,
focus specifically on the Spanish vowel system, and review a number of impressionistic
and acoustic studies of Spanish vowels.
2.2.2 Impressionistic studies of Spanish vowels
Prior to the invention of the sound spectrograph in the 1940’s (Koenig et al.,
1946), the majority of the studies pertaining to Spanish vowels had to be conducted on an
impressionistic basis; with the researcher listening and transcribing what he or she heard,
but having no way to quantify or systematically test the claims that were being made.
One of the earliest linguistic descriptions of the Spanish vowel systems was provided by
37
Navarro-Tomás (1918) in his Manual de pronunciación española. Perhaps one of the
most well-known and frequently cited authors in Spanish linguistics, Navarro-Tomás
described the manner in which the Spanish vowels should be pronounced and detailed
how different consonantal and syllabic contexts affected their pronunciation. First and
foremost, his manual is a comprehensive and descriptive guide to Spanish pronunciation
intended for the learner of Spanish. The goal was to present guidelines for the “correct”
pronunciation of the Spanish language; the educated variant spoken in Castile, Spain, at
the beginning of the 20th century.7 The author begins by describing the different
anatomical structures responsible for producing speech sounds and continues on to
describe the parameters in which each of the Spanish vowels and consonants are made.
In his description of Castilian Spanish vowel pronunciation, Navarro-Tomás
(1918, p 40) explained that the Spanish alphabet only distinguishes between 5 vowel
sounds: a, e, i, o, u, and sometimes y when it is pronounced as a vowel and thus has the
same pronunciation as i. Despite the simplicity in orthography, however, he argued that
each of these five vowels has at least three distinct allophones, each surfacing based on
the stress context and surrounding consonantal and vocalic context. The low vowel /a/
was argued to be either media (middle/central), palatal (palatal), velar (velar), or
relajada (relaxed). In the majority of instances, the /a/ is pronounced as a central vowel,
having the greatest degree of aperture of the lips of all the vowels, and the tongue in the
lowest position. In the context of other palatal sounds, such as /ñ/, it is articulated
slightly differently with the tongue more closely situated toward the palate. The /a/ is
said to be a velar variant and articulated farther back in the mouth when it forms part of a
7 Navarro-Tomás clarifies his usage of the term “correct” by arguing that it does not imply that the Castilian variety is superior to any other dialect of Spanish, but rather as a means to distinguish it from other varieties spoken throughout Spain and Latin America.
38
diphthong with /u/ or occurs before a /u/ or an /o/, in a syllable that is closed by an /l/, and
before the velar /x/. A relaxed /a/ is said to occur in final position before a pause, word-
internally or group-internally, and between relatively unaccented syllables (p. 55-57).
The other four vowels were argued to have three distinct variants each: cerrada
(closed), abierta (open), and relajada (relaxed). The relaxed variants of all four vowels
were described as occurring most frequently in rapid and conversational speech when
they are situated between the primary and secondarily stressed vowels and in word-final
position before a pause. The closed and open versions of the high vowels /i/ and /u/
pattern similarly. The closed allophones were described as having slightly more extreme
tongue positions, with the closed /i/ being situated closer to the teeth and alveolar ridge
than the open variant, and the closed /u/ exhibiting a tongue position closer to the velum
than the open articulation of the same vowel. The closed allophones of /i/ and /u/ occur
with both tonic and atonic vowels in open syllables. The open allophones of /i/ and /u/,
with more retracted tongue positions, were described as most common when they occur
in contact with /r/, in closed syllables, and before the velar /x/. The mid vowels /e/ and
/o/ exhibit a similar parallelism. The closed allophones of these vowels have more
advanced tongue positions when compared to their open counterparts. Like the high
vowels, the closed mid vowels are most common in open syllables. The open allophones
of both mid vowels occur when in contact with /r/, before the velar /x/, and for /o/, in
closed syllables. The open /e/ (i.e., [ε]) was argued to occur in closed syllables as well,
as long as the closing consonant was not /d, m, n, s, x, z/. Table 2-2 below provides a
more comprehensive representation of each of the vowel allophones and the contexts in
which Navarro-Tomás argued they occur.
39
Table 2-2
Vowel pronunciation described in Navarro-Tomás (1918)
Orthography Variant
Symbol used by
Navarro-Tomás
Contexts
closed i tonic open syllables; atonic open syllables in slow speech.
i open į
closed syllables, especially those spoken with intensity; in contact with /r/; before /x/.
relaxed ị
conversational and rapid speech; when situated between a primary and secondary accent.
closed e
open syllables with primary or secondary stress; in syllables closed by orthographic m, n, s, d, z; followed by orthographic x and another consonant
e
open ę (ε)
when followed or preceded by /r/; before /x/; in the diphthong /ei/; syllables closed by any consonant other than orthographic d, m, n, s, z; before orthographic x when pronounced as [ɣs].
relaxed ǝ
conversational speech, situated between a primary and secondary accent, word-final position before a pause.
central a
tonic syllables, both open and closed, when not in contact with a palatal or velar consonant.
a palatal a before palatal consonants; in the
diphthong /ai/.
velar ạ
when forming part of the diphthong /au/; before an accented /u/; before an /o/; in a syllable closed by /l/; prior to /x/.
relaxed ᵄ
word final position before a pause; word or group-internally when situated between relatively unaccented syllables.
closed o
open syllables with the primary or secondary accent; more closed at the end of a word when forming a diphthong with a /u/ in the following word.
o
open ǫ (ɔ)
when in contact with /r/; before /x/; in the diphthong /oi/; in syllables closed by any consonant; in accented position between an /a/ and a following /l/ or /r/.
40
relaxed o
conversational speech in word-word final position before a pause; word or group-internally when situated between accented syllables.
closed u rapid speech; tonic open syllables;
atonic open syllables; in slow speech.
u open ų when in contact with /r/; before /x/; in
syllables closed by any consonant.
relaxed u
conversational speech in weak position; between a primary and secondary accent .
Note. The phonetic symbol provided in the third column are those utilized by Navarro-Tomás in text. When applicable, the symbols from the International Phonetic Alphabet (IPA) are included in parentheses.
Despite the detailed descriptions in which each of these allophones surface and
the distinct phonetic symbols assigned to each, Navarro-Tomás (1918) discussed that the
differences between the open, closed, and relaxed versions of Spanish vowels are very
slight. He also emphasized that the difference between the closed and open allophones of
the mid vowels /e/ and /o/ tended to be more noticeable than the same differences in the
high vowels /i/ and /u/. The distinction between the palatal /a/ and the central /a/ was said
to be so slight that they were not assigned separate symbols as the difference was
supposedly nearly imperceptible. The detailed account of vowel timbre within the
system, however, does indicate that there is some variation in terms of quality within the
five vowel system. The author lamented that an acoustic analysis of Spanish vowel
quality had yet to be conducted at the time his text was written.
The discussion of vowel quality is followed by an explanation of differences in
vowel quantity (duration), and how different stress and consonantal contexts result in
vocalic duration of varying lengths. He argued that duration should be considered in
terms of relative duration, in that the length of any given sound varies as a function of
41
speaking rate and emotive and emphatic qualities of speech. Navarro-Tomás (1918)
divided Spanish vowels into three durational categories: largas (long), semilargas (semi-
long), and breves (short). The stressed vowels in final position that are not followed by
/n/ or /l/ were agued to have the longest duration, ranging from 15-20 hundredths of a
second, and were classified as long (largas). Final stressed vowels followed by /l/ and /n/
and stressed vowels in an open penultimate syllable (i.e., grave, or palabras llanas) were
classified as semilong (semilargas), ranging in duration from 11.5-15 hundredths of a
second. The shortest vowels (breves) are those vowels which occur in closed penultimate
and when the vowel occurs in the antepenultimate syllable. The duration of the accented
short vowels was described as falling between 7.5 and 10 hundredths of a second. A final
observation pertaining to the length of stressed vowels is that the following consonant
may influence its overall duration. Vowels in the context of /r,b,d,g,y/ tend to be slightly
longer than when they are in contact with other consonants.
Navarro-Tomás (1918) argued that the unstressed vowels were shorter in duration
than their stressed counterparts, and therefore none could be considered to be long.
According to his impressionistic description, only in emphatic or slow speech does the
duration of an unstressed vowel approximate that of a stressed vowel. The shortest
duration is observed in the posttonic vowel in words with antepenultimate stress (i.e., the
u in the word capítulo “chapter”). Vowels in this position were described as ranging
between 5.7 and 5.8 hundredths of a second. An unstressed vowel in word-initial
position was considered to be slightly longer, often classified as semi-long. The duration
ranged from 10.5 to 12 hundredths of a second. In slow and careful speech, however,
unaccented vowels in any position within the word were argued to lengthen, resulting in
42
their approximating the duration of a stressed vowel. Unlike the stressed vowels, there is
supposedly very little durational differences between atonic vowels that occur in closed
syllables versus those that occur in open syllables.
In addition to providing details about the articulation, timbre, and duration of the
Spanish pure vowels, Navarro-Tomás (1918) made four important generalizations about
the vowel system that will be discussed throughout this dissertation. First, he argued that
the timbre of the Spanish vowels was generally invariable throughout the sound,
exhibiting a great deal of uniformity (p. 43). In certain dialects, in instances of “strong”
pronunciation, and in slow speech he argues that a certain vowel sound may lengthen, but
the general assumption remained that Spanish vowel sounds have a somewhat stable
timbre throughout their articulation. A second important characteristic of Spanish vowels
was that unstressed vowels, especially word-final vowels and those in antepenultimate
position had a tendency to relax, resulting in a timbre that was less defined and precise (p.
44). In careful, slow, or emphatic speech, he argued that these same vowels did not
undergo relaxation and instead maintained their clarity.8 The third general claim about
the Spanish vowel system was that unstressed vowels are shorter than the stressed
vowels, but that the difference between the two is very slight. As will be explained
further below, the general assumption has remained that Spanish vowels do not show
extreme differences in duration based on their stress context, but more recent
investigations have put this claim into question (Marín Gálvez, 1995). A fourth and final
implied assumption about the Spanish vowel system is that both vowel quality and vowel
duration are affected by speech style. Throughout his text Navarro-Tomás argued that
8 As will be described in greater detail in section 2.2.3, the majority of the acoustic investigations of Spanish vowels have analyzed highly controlled speech samples (i.e. careful, slow, and emphatic speech).
43
vowels relaxed and become shorter in conversational speech, and were less relaxed and
longer in duration in careful and emphatic speech. As will be demonstrated in the
sections that follow, very few investigations have directly examined the connection
between speech style and vowel production.
In addition to Navarro-Tomás’s (1918) seminal work on Peninsular Spanish,
impressionistic studies of Spanish vowels extend to other regions in the Spanish-speaking
world. Of particular interest in this dissertation are studies pertaining to vowel
pronunciation in central Mexico, as all but one of the participants in this investigation are
of Mexican heritage. Henriquez Ureña (1921) was the first to comment that the atonic
vowels in Mexican were very short in duration, “reduced,” and often deleted in certain
contexts. This observation resulted in several additional impressionistic studies of
unstressed vowel reduction (hereafter UVR) or deletion that examined the contexts in
which this reduction occurred.
Boyd-Bowman (1952) and Matluck (1952) were the first two studies to address
the pronunciation of unstressed vowels in Mexican Spanish. Boyd-Bowman’s study,
which focused on the Altiplanicie de México and includes Mexico City and Guanajuato,
was based solely on his impressions overhearing the pronunciation of certain words
during his time in the region. He argued that the reduction and loss of atonic vowels was
most frequent when in contact with the sibilant /s/ and another voiceless consonant. This
reduction was even greater when the atonic vowel was in contact with a word-final /s/.
He argued that all vowels except for /a/ underwent reduction in the sample expressions he
heard.
44
Matluck (1952) described the same phenomenon in the Valle de México—a larger
region that encompasses Mexico City, a large portion of the state of Mexico, as well as
portions of the state of Hidalgo. His analysis was much more in-depth than Boyd-
Bowman’s two page study, but was still based on his impressions of the pronunciation of
the vowels and not on acoustic measurements. He first described some of the differences
between the pronunciation of vowels in Mexico and those of Spain, as described by
Navarro-Tomás (1918). He argued that the Mexican pronunciation of /a/ did not exhibit
as much velarization as the /a/ in standard Spanish. He also noted differences in the
articulation of the mid vowel /e/ according to syllable structure. Whereas Navarro-
Tomás argued that the mid vowel /e/ was produced as a closed variant [e] in a syllable
closed by orthographic m, n, s, z, d, x, in the Valle de México the /e/ in syllables closed
by any consonant was produced with the open variant [ε]. In his examination of UVR, he
observed that in the speech of the middle class (i.e., among the semicultas) and the lower
classes, the initial unstressed vowel in a word had a tendency to delete, resulting in the
lengthening of the following consonant (enero n:ero “January”). He also argued that
when a vowel occurred in absolute initial position, or occurred after another word ending
in a vowel, the unstressed vowel could disappear when in contact with /s/ (está bien
stábien “he/she/it’s good”). In contrast to an initial unstressed vowel, vowels in word-
internal position were argued to reduce but rarely delete. Final unstressed vowels were
argued to be greatly reduced and could often disappear. Matluck, like Boyd-Bowman,
argued that a vowel followed by a voiceless consonant, and especially /s/, had the greatest
likelihood of reducing or devoicing. Finally, he commented that a final /e/ in contact
45
with a palatal consonant could often be produced as /i/, as in the word noche nochi
(“night”).
By far the most comprehensive investigation of UVR in Mexican Spanish was
carried out by Lope Blanch (1972). Although no acoustic or statistical analyses were
conducted, he was able to analyze which consonantal contexts and vowel positions were
most subject to reduction by examining the percentage of cases that occurred in each
category. He collected data from 100 speakers residing in central Mexico that he argued
represented all social classes and educational levels. The speech was classified as
spontaneous, and was gathered based on conversations he had with each participant
dealing with topics of daily life, conversations about radio programs, personal interests,
and other spontaneous discussions. All speakers were between the ages of 15 and 60
years, including both men and women. Nearly all of the participants interviewed were
born in Mexico City, and those who were not born in the area had resided in the city for
at least 20 years. Fifty two of the interviews were recorded on magnetic tape so that their
pronunciation could be examined multiple times if necessary. The data from the
remaining 48 speakers was not recorded, but detailed notes pertaining to their
pronunciation were compiled during the time of the interview.
Although 100 speakers were interviewed, Lope Blanch’s (1972) main analysis
was based on the 52 recorded interviews. In total he analyzed 2,284 vowels “by ear” (p.
57), and determined that there were four degrees of vowel weakening ranging from
simple relaxation to complete loss. The criteria with which Lope Blanch determined
these degrees of weakening is not explained in detail, thus it is difficult to determine
exactly how he classified the vowel articulations he heard. Based on his impressionistic
46
analysis, several important characteristics of UVR in Mexican Spanish were described.
Lope Blanch argued that the position of the vowel within the word was not as influential
in weakening as argued by Matluck (1952) and Boyd-Bowman (1952), but rather that it
was determined by the nature of the surrounding consonantal context. Unstressed
vowels in contact with voiced consonants were not found to show reduction or deletion.
He found that among the consonantal contexts that most favored deletion or reduction,
nearly 90% of the cases of reduction occurred when a vowel was in contact with /s/ -- an
observation made by both Matluck and Boyd-Bowman in their investigations. The vast
majority of these cases were observed when /s/ followed the vowel as opposed to
preceding it. He then analyzed the frequency of occurrence of reduction in several
different consonant + /s/ contexts, and found that /s/ + /s/ accounted for 22.9% of cases of
reduction. The groups /p/ + /s/, /t/+ /s/, and /k/ + /s/ also favored reduction, at rates of
9.7%, 13.7%, and 9%, respectively. In the rare cases in which an /s/ preceded a reduced
vowel, the following consonants that most favored reduction were the nasals /m/ and /n/
with 12.8% and 14.3% of the cases, respectively. In his analysis of the open syllables,
vowels in contact with the voiceless stops /p t k/ were reduced more frequently than when
they were in contact with any other consonant.
In terms of the type of reduction (i.e., relaxation or full deletion), he reported that
only 17.5% of the reduced vowels were classified as complete deletions.9 A closer
examination of the tokens in which full deletion occurred, however, revealed that most of
the deletion was isolated to the words pues (“well”) and entonces (“then”). Once these
tokens were excluded, only 9.8% of all reduced vowels were argued to be fully deleted.
9 As described previously, Lope Blanch did not provide well-defined criteria for determining how the vowels were grouped into the four different categories of reduction.
47
In terms of the individual vowels that were most subject to reduction, he reported that
42% of the cases involved the vowel /e/, followed by /o/ with 24%, and /i/ with 5.6%.
The /a/ was found to be resistant to reduction, accounting for 7% of the cases. As /a/ is
the most frequent vowel in Spanish, however, its higher percentage of reduction
compared to /i/ was explained as a frequency effect and not that it was more likely to
reduce than /i/. No information pertaining to the rate of reduction of /u/ was reported.
Lope Blanch’s (1972) analysis is the most complete and most quantitative of all
three investigations focusing on UVR in Mexican Spanish. His analysis indicated that
the consonantal context in which a vowel occurred was the most important characteristic
influencing UVR. Unstressed vowels in contact with /s/, and especially surrounded by
/s/, showed the greatest rate of reduction. The vowel /e/ was also shown to reduce more
than any other vowel, at least in this variety of Spanish. At the end of his manuscript,
Lope Blanch indicated that several of his colleagues had reported similar pronunciation in
regions of Ecuador, Bolivia, and Argentina. He concluded that this phenomenon may be
more common in the Spanish language than previously believed, and that additional
investigations should analyze its presence in other geographic regions.
Despite his detailed account of the Mexican pronunciation, morphology, syntax,
and lexicon, Lipski (1994; 2008) offers little additional information about the
pronunciation of vowels in Mexico. In his 1994 text, he reiterates that central Mexico is
distinguished from other regions within the country and other regions in Latin America
by the tendency of unstressed /e/ to reduce when in contact with /s/. In his description of
Mexican American Spanish, he argues that the vowel /i/ is also subject to this process.
In addition, he indicated that the pronunciation of the Spanish vowel /e/ in Mexican
48
American varieties of Spanish was often produced lower and farther back in the vowel
space, more closely approximating the pronunciation of /ε/ in the English word let.
Taken together, these investigations of Mexican Spanish vowel pronunciation indicated
that UVR is one of the most distinguishing characteristics of this dialect. As the heritage
speakers who participated in this investigation are speakers of Mexican American
Spanish, the acoustic analyses conducted in this dissertation will help determine if they
exhibit UVR, and if so, how is it characterized (i.e., quality reduction and centralization
or devoicing).
The impressionistic studies of vowels discussed in this section were some of the
first to provide descriptions of the Spanish vowel system.10 Navarro-Tomás’s (1918)
detailed account provided that basic description to which other researchers would
compare their work – both impressionistic and acoustic – and contains a number of
claims that may have influenced researchers to avoid the analysis of vowels (i.e., the
implied notion of stability). Additional studies conducted in the mid to late 20th century
showed that Mexican dialects of Spanish are dissimilar from Peninsular varieties,
especially with respect to their reduction of unstressed vowels. Despite the differences
between dialects – distinctions which had been noted as early as 1952 – the assumption
has generally remained that Spanish vowels do not exhibit great degrees of variation
across dialect. Many introductory textbooks on Spanish pronunciation and phonetics cite
Navarro-Tomás as one of the authorities on Spanish vowels, and argue for a simple,
stable, symmetrical five-vowel system. As will be demonstrated in the following
sections, acoustic studies of Spanish vowels have offered additional insight into the
vowel system of several different varieties of the language. Acoustic methodologies have 10 See also Amastae (1982) for a morpho-phonological account of mid vowel raising in Spanish.
49
permitted a more thorough examination of the claims put forth by Navarro-Tomas
(1918), Boyd-Bowman (1952), Matluck (1952) and Lope Blanch (1972).
2.2.3 Acoustic studies of Spanish vowels
As the sound spectrograph and use of spectrograms to measure formant
frequencies became more readily available, impressionistic accounts of Spanish vowels
became less frequent, being replaced by instrumental and experimental acoustic studies
of vowels, and more predominantly, of consonants. The purpose of the following section
is to describe several notable acoustic descriptions of Spanish vowels, beginning with
earliest and progressing semi-chronologically and thematically to the present day. The
findings from the collection of investigations described below will demonstrate the
degree to which researchers differ in how they describe the Spanish vowel system. This
disagreement is one of the main factors guiding the research questions in this dissertation.
The summary of these investigations also demonstrates the importance of acoustic
analysis in the description of phonetic and phonological systems, and how careful,
quantitative measures of speech can reveal details and variation within the system that are
often not perceptible by impressions alone.
One of the earliest and most comprehensive acoustic analyses of Spanish vowels
was conducted by Quilis and Esgueva (1983).11 They analyzed the speech of 22
informants, 16 males and 6 females, from varying regions within Spain, Mexico, and
11 Prior to Quilis and Esgueva´s (1983) study, Skelton (1969) and Guirao and Borzone de Manrique (1975) conducted acoustic studies of Spanish vowels. Skelton´s study will be discussed later on in this chapter with the other investigations of syllable type. Guirao and Borzone de Manrique´s study of Argentinian Spanish showed variation of vowel articulations based on consonantal context, and compared Spanish vowels to the Cardinal English vowels. The methodology and description of the results, however, are difficult to follow, and no clear and describable trend emerged. Also, as this investigation also examines Argentine Spanish vowels, it does not have a direct connection to the present study. For these reasons, these two earlier acoustic investigations will not be discussed in great detail here.
50
Latin America. The participants were asked to read a target word that was embedded
within a carrier phrase, the target word containing the vowel of interest.12 Unlike other
earlier acoustic studies (e.g., Guirao & Borzone de Manrique, 1975) they included both
tonic and atonic occurrences of each vowel and investigated three different consonantal
contexts that included nasal and non-nasal sounds. The corpus of target words consisted
of three examples of each of the five Spanish vowels in tonic and atonic position
embedded within the contexts of p-p, b-b, and m-m. In total, each speaker produced 30
vowels. The first, second, and third formant frequencies, as well as the total duration of
each vowel, were calculated for each speaker using the Sona-Graph 6061B device.13
Analyses for each individual speaker were calculated separately and were plotted within
the traditional format of the vowel triangle as a means and clouds to demonstrate the
location of the vowels in the acoustic space.14 Examination of each individual speaker’s
production revealed several overall trends in terms of vowel quality (formant
frequencies) and vowel duration, which will be discussed below in further detail.
The results of the formant analyses showed little differences between the tonic
and atonic vowels in terms of their position within the acoustic space. For both the male
and female participants, there was very little difference between the tonic and atonic
productions such that no consistent trend could be identified. The male participants had a
slight tendency to produce tonic vowels with a more open articulation, whereas no
correlation between aperture and tonicity was reported for the female speakers. One
12 The carrier phrase task employed by Quilis and Esgueva (1983) represents the most careful and formal speech style, and is the methodology employed in the majority of the acoustic studies of Spanish vowels. 13 It is unclear which portion of the vowels (i.e. onset, midpoint, or offset) were analyzed in this study. The authors describe that once the words were recorded with previously known techniques, they proceeded to the acoustic analysis using the Sono-Graph 6061B, (p. 163, my translation). As the most common point of measurement is the midpoint, one can assume that the formant values were extracted from the center point. 14 See figure 2-1 for the average values produced across speakers.
51
unexpected finding was that the female informants produced vowels that occupied a
larger portion of the acoustic space when compared to the male speakers. The acoustic
space for the male speakers was found to be smaller and more centralized than that of the
females, and also exhibited a slight backing of the vowels /a,o,u/. Finally, the overall
values across all participants were calculated and plotted against the cardinal vowel
triangle in order to depict the “vowel triangle for the Spanish language” (p. 251, my
translation). They report that the Spanish vowels analyzed in this study differ greatly
from the prototypical, synthesized cardinal vowels, with the /i a u/ being farther back in
the space and /e/ and /o/ being pronounced with a more open articulation.15
With respect to vowel duration, the tonic vowels for all participants were found to
be longer than the atonic vowels. The consonantal context also influenced duration, with
all but one of the participants producing the shortest vowels in the context of /p/, slightly
longer vowels in the context of /m/, and the longest vowels in the context of /b/. Finally,
the authors reported that the vowels produced by the female informants were longer
overall than those produced by the male informants.
The findings in the seminal acoustic study by Quilis and Esgueva (1983) provided
some of the earliest acoustic descriptions of the Spanish vowel system, and advanced the
understanding of vowels by reporting numeric values and visual representations of
speech production. Despite its contribution, however, this investigation lacked statistical
analyses, and thus the ability to determine if the differences (or lack thereof) were
consistent or significant. In the following decades, additional acoustic research expanded
15 Unfortunately, although an analysis of F3 was carried out in this study, there is very little description or discussion of these results. The authors describe that the values of F3 varied greatly, and present a table of values for the male and female speakers demonstrating where the values were obtained. There is no further discussion of the F3 values other than presenting the means values averaged across the male and female speakers.
52
upon this investigation by including statistical analyses and more concrete descriptions of
formant values, vowel duration, and the dispersion of vowels within the acoustic space.
The subsequent studies verified the acoustic correlates necessary to distinguish Spanish
vowels, offered further insight into the effect of lexical stress and syllable type on vowel
production, and examined the effects of speech style on the pronunciation of Spanish
vowels.
The goal of Martínez-Celdrán’s (1995) acoustic study was not to describe the
Spanish vowel space per se, but rather to examine the five Spanish pure vowels and
determine what acoustic parameters are sufficient to distinguish them. A second goal of
this study was to identify the limits for each of the spaces (campo de dispersión) in order
to facilitate the possibility of a vowel recognition system that could accurately identify
each vowel based on its F1 and F2. The procedure for the series of experiments seems to
have taken place in two distinct steps, although the description of the tasks is somewhat
unclear. For the formant analysis, five male and female speakers produced each of the
five Spanish vowels embedded within the contexts pamp/bVna, tant/dVna, kank/gVna,
resulting in 30 tokens per person and 300 in all for the ten informants. The midpoint of
each tonic vowel was calculated by examining the wide-band spectrograms. For the
recognition software system, five male speakers produced 100 isolated CVCV and
VCCV words in which the consonant was always a stop or a fricative. The words were
then digitized and the values for bandwidth, amplitude, intonation, and F1-F4 were
calculated at 10ms time steps throughout the production16.
16 Very little detail pertaining to the methodology of this study was provided. It is unclear if the words used in this task are real or nonce words. It is also unclear if the same five male participants completed both production tasks.
53
Statistical analyses of the F1 and F2 measures for the male and female
participants revealed that the first formant frequency was sufficient to distinguish the
Spanish vowels in terms of height, grouping the vowels into three categories: high, mid,
and low. The second formant frequency was confirmed as an accurate predictor of vowel
backness, resulting in three distinct groups: front, central, and back. The author argues
that F2 is actually the more important of the two cues in distinguishing the five vowels
based on the higher discriminant functions that were obtained when only F2 was
included. The second formant predicts with 100% accuracy the recognition of the low
vowel /a/ and with approximately 80% accuracy the other four vowels, whereas F1 did
not predict any of the vowels with 100% accuracy and the back vowels /o/ and /u/ with
only 52 and 53% accuracy, respectively.
An additional finding of the formant analysis revealed that male and female
formant distributions differed significantly from one another. Overall, the analyses
indicated the F1 and F2 values for the female speakers were higher than those of the male
speakers, resulting in an acoustic distribution that was shifted downward and farther front
when plotted in the acoustic domain. These differences are similar to those reported by
Quilis and Esgueva (1983), who described a larger, more expanded vowel space for
females.17
The investigations conducted by Quilis and Esgueva (1983) and Martínez-Celdrán
(1995) are two of the earliest and most comprehensive acoustic analyses of Spanish
vowels.18 Each study provided vital information pertaining to the acoustic nature of the
17 Neither Martínez-Celdrán (1995) nor Quilis and Esgueva (1983) normalized the formant values produced by the male and female speakers. 18 Two additional acoustic studies of Mexican Spanish vowels were conducted by Servín and Rodríguez (2001) and Martín Butragueño (2011). Both of these investigations provided formant values for male and
54
Spanish vowel system, arguing for little differences in vowel production based on lexical
stress and dialect, notable differences in pronunciation based on speaker gender, and
confirmed that the first two formant frequencies were the most important when
characterizing Spanish vowel production. These investigations were general, focusing
on the overall distribution and the basic characteristics of the system. Several other
acoustic investigations have examined more specific aspects of Spanish vowel
pronunciation, in particular the effects of lexical stress, syllable type, and speech style on
the acoustic properties of vowels.
2.2.3.1 Lexical Stress
Despite the fact that Navarro-Tomás (1918) and several studies of Mexican
Spanish (Boyd-Bowman, 1952; Matluck, 1952; Lope Blanch, 1972) argued for
differences in vowel quality based on lexical stress, most textbook descriptions of
Spanish vowels argue that the language exhibits little differences between the quality of
tonic and atonic vowels (Hualde, 2005). A very early study conducted by Delattre (1969)
confirmed the lack of reduction of Spanish atonic vowels, especially when compared to
three other languages. He examined the differences between stressed and unstressed
vowels in Spanish, English, German, and French via the reading of isolated words with
alternating stress patterns. Five male native speakers of each language read each of the
target words twice. The first and second formant frequencies were then extracted from
the target vowels in each word, and were plotted in order to compare the degree of
centralization in each language. Delattre’s analyses revealed that English showed the female speakers of Mexican Spanish, but also had more specific foci. Servín and Rodriguez (2001) specifically examined the effect of syllable type on vowel production, and for this reason will be discussed in greater detail in section 2.2.3.2. Martín Butragueño (2011) examined the amount of overlap present in the vowel categories of male and female speakers, and also examined how speech style on vowel production. This study will be explained in greater detail in section 2.3.2.3.
55
greatest degree of unstressed vowel reduction, followed by German and French, and
Spanish with the least amount of reduction. A closer examination of the patterns of
reduction indicated that the high vowels were not significantly affected by lexical stress,
that the mid vowels showed some centering, and that the /a/ was raised and centered
when atonic. In addition, he argued that the front vowels showed a greater effect of
lexical stress than the back vowels, indicating that the unrounding of the back vowels did
not play a significant role in unstressed reduction. His analysis also revealed that Spanish
did not have the vowel schwa that occurs in English, which lead Delattre to argue that
this is “one more sign of syllabic equality” in Spanish (p. 323). He subsequently argued
that the lack of reduction observed in Spanish is attributed to the “perfect balance of the
Spanish vowel system: two front, two back, and one central” (p. 324). The findings
reported in this investigation, thus, may have resulted in the overarching assumption that
Spanish does not, in fact, exhibit quality differences based on lexical stress.
A more recent acoustic analysis conducted by Delforge (2008) on Andean
Spanish did report differences in vowel production based on lexical stress, but not in
terms of vowel quality and centralization as argued by Matluck (1952) and Lope Blanch
(1972) for Mexican Spanish. Delforge’s investigation of the Spanish of Cusco was aimed
at more accurately describing (UVR) in Peruvian Spanish via spectrographic and
statistical analyses. Unstressed Spanish vowels were obtained from 10-minute-long
spontaneous speech samples produced by 16 native-speaking residents of Cusco, Peru.
Fourteen males and 2 females ranging in age from 24-90 years took part in the
interviews. Nine of the speakers were also bilingual in Quechua, although Delforge
56
confirmed that all of the bilinguals had learned Spanish first and were more accurately L2
speakers of Quechua.19
The examination of the vowel productions indicated that of the 16,581 unstressed
vowels produced across all speakers, 1,648 (9.9%) were identified as reduced.
Additional spectrographic analyses of the reduced tokens indicated that as suggested in
Lope Blanch (1972), “reduction” was a gradient phenomenon. Based on the acoustic
characteristics of the unstressed vowels, Delforge determined four degrees of reduction
which she argued were not necessarily mutually exclusive: devoiced/shortened, weakly
voiced, completely devoiced, and apparently elided. As more than 50% of the reduced
tokens exhibited some degree of devoicing, a more accurate description of the reduction
phenomenon in this variety of Spanish was determined to be “unstressed vowel
devoicing” as opposed to quality reduction.20 The vowels most subject to devoicing were
found to be /e/, /i/, and /u/. An analysis of word position indicated that although overall
devoicing rates were higher in word-final position, /u/ in word-medial position actually
exhibited more devoicing than /u/ produced in final position. The rate of devoicing in
final syllables closed by /s/ was also found to be less than that reported by Lope Blanch,
who argued that this environment most favored UVR. Finally, an analysis of the
consonantal contexts most favoring unstressed vowel devoicing revealed differences
between Delforge’s spectrographic analysis and Lope Blanch’s impressionistic account.
19 It is important to note that Quechua has a 3-vowel system consisting of /i a u/. 20 Additional analyses of the F1 and F2 of stressed and unstressed vowels confirmed that centralization in terms of quality was not a characteristic of Cusco Spanish. These additional analyses indicated that there were no significant differences between the formant values of unstressed reduced, unstressed unreduced, and stressed vowels in this variety.
57
Vowels that were in contact with any voiceless consonant, and most importantly
affricates and assibilated /r/, showed greater influences than /s/.
Overall, Delforge’s (2008) analysis of UVR in Andean Spanish showed how
detailed, acoustic analyses offer insight into processes that had previously been described
impressionistically. Through the use of spectrography, she was able to determine that
what had previously been described as “reduction” and assumed to refer to quality
reduction or centralization was more accurately a type of gradient devoicing. This
investigation also proved that at least for Andean Spanish, the high vowels were most
subject to devoicing, voiceless consonantal contexts other than /s/ resulted in devoicing,
and that this process occurred more frequently in word-medial position than traditionally
argued. Her findings also corroborate those of Delattre (1969) who argued for the
absence of centralization of unstressed vowels in Spanish.
Unstressed vowels have also been shown to reduce in duration. An acoustic
examination of vowel duration conducted by Marín Gálvez (1995) analyzed the
production of vowels by two male speakers of Peninsular Spanish. Each participant read
two texts taken from a newspaper that had been modified slightly in order to incorporate
tonic and atonic vowels in open and closed syllables. In total, 491 vowels were analyzed
acoustically for each speaker. The results of their assessment of duration indicated that
overall, atonic vowels were shorter than tonic vowels. This difference was found to be
statistically significant based on the results of t-tests. Analyses of each of the vowels
separately indicated that the pattern was consistent across each vowel as well; the atonic
productions exhibited significantly shorter duration than tonic vowels in all cases except
/u/ in which the difference was not statistically significant. Thus, these findings confirm
58
Navarro-Tomás’s impressions that unstressed vowels were shorter and reduced in
comparison to their tonic counterparts.
Taking into consideration all of the acoustic and impressionistic studies of
unstressed vowel reduction in Spanish therefore results in an unclear picture of the effect
of lexical stress on vowel production. Whereas some studies suggest the presence of
differences in quality and duration based on stress context (Lope Blanch, 1972; Marín
Gálvez, 1995; Navarro-Tomás, 1918), others indicated a lack of centralization (Delattre,
1969). Furthermore, what had previously been described as “reduction” was determined
by Delforge (2008) to actually be devoicing and not centralization for a Peruvian dialect.
These inconsistencies in the literature in part motivate the need to further examine the
effect of lexical stress on vowel production in Spanish. The present study includes an
acoustic analysis of the effects of this linguistic variable on both quality and duration,
thus offering insight into how stress differences are manifested in heritage Spanish.
2.2.3.2 Syllable type
Recent acoustic examinations of the effects of syllable structure on monolingual
Spanish vowel production conflict considerably with the detailed descriptions provided
by Navarro-Tomás (1918). As mentioned previously, even Matluck (1952) argued that
the closed and open syllable type contexts described by Navarro-Tomás, especially for
the mid vowel /e/, did not apply to Mexican varieties of Spanish. These early
impressionistic comparisons between the categories described by Navarro-Tomás suggest
that his distinction may not be robust, and that it may, in fact, differ according to dialect
region.
59
The only acoustic investigation that seems to have confirmed the presence of mid
vowel allophones was conducted by Skelton (1969). He analyzed the vowel production
of 20 native speakers of Spanish from varying regions within Spain and the Americas.
The utterances contained the five Spanish vowel phonemes in the contexts in which
Navarro-Tomás (1918) indicated there would be variation. Overall, Skelton reported a
considerable amount of overlap between the vowel categories. Of particular interest was
the overlap that occurred between the high front and mid front categories corresponding
to the vowels /i/ and /e/, respectively. He reported that the only examples of the mid
vowel /e/ that overlapped with the high vowel space were those that were produced in
open syllables and termed “close” by Navarro-Tomás. Based on Skelton’s description of
the back vowels, it is difficult to discern if the same pattern was observed for the mid
back vowel /o/. Thus, at least for the front mid vowel /e/, Skelton argues that the overlap
of the /e/ in open syllables with the space of /i/, but no such overlap with /e/ in closed
syllables evidenced two distinct allophones. Unfortunately, Skelton’s description of the
methodology and representation of the results are not clear. In addition, he did not use
any statistical methods to support his findings. For this reason, his investigation is
difficult to interpret and the findings should be taken with caution.
In contrast, several other investigations have provided evidence that the mid
vowel allophony that was argued to arise as a consequence of syllable structure is not
borne out by the acoustic data. Although not separate studies dedicated to the analysis of
syllable structure, Jurado and Arenas (2005) and Martínez-Celdrán (1984) do mention the
effect of syllable type on the pronunciation of Argentinian and Peninsular Spanish
vowels, respectively. Jurado and Arenas (2005) reported a radiographic study they
60
conducted in 1981 with one male speaker of Argentinian Spanish. They do not provide
information pertaining to the study itself in terms of how the data were collected and
analyzed. At the end of a short paragraph, they conclude that the mid vowels exhibit
variation between [e] and [ɛ] and [o] and [ɔ], but the open variants of the vowels only
occur in syllables closed by /r/.
Martínez-Celdrán (1984) analyzed the first and second formant frequencies of
vowels produced by male speakers. He then compared these productions to the
categories described by Navarro-Tomás in order to determine if the acoustic data
supported the distinction between mid, close, and open vowel allophones. For the mid
vowels specifically, he found that the correspondence between the productions of his
speakers and the categories set forth by Navarro-Tomás only amounted to about 50%.
Based on these findings, he concluded that the effect of syllable type on vowel
production in Spanish was not consistent as no clear pattern emerged.
Two larger-scale studies of mid vowel variation in Spanish were conducted by
Servín and Rodríguez (2001) and Morrison (2004). Servín and Rodríguez examined the
differences in vowel articulation based on syllable structure in the speech of four
speakers of Mexican Spanish. Two male and two female natives of Mexico City
completed a carrier phrase task in which 30 words were embedded. Six utterances of
each of the five vowels were included, with three words representing the vowel in an
open syllable and three representing the vowel in a closed syllable.21 The first three
formant frequencies were measured at the stable point within the vowel. A comparison
21 The consonantal contexts represented in Servín and Rodríguez do not correspond exactly to those described by Navarro-Tomás. In particular, a syllable closed by /s/ was classified with all other closed syllables, and not with the open syllables as indicated by NT. This categorization is consistent with the observation that for Mexican Spanish, a syllable closed by the consonant /s/ results in the open allophone [ɛ] (Matluck, 1952).
61
of the formant values for vowels produced in open and closed syllables indicated that
there were very little acoustic differences between the two. The mid vowels showed
slight differences, with those produced in closed syllables exhibiting a slightly more open
articulation than those in open syllables, but these differences were minimal. As no
statistical analyses were conducted, it was not possible to determine if the tendencies
were statistically significant or not. Regardless, the authors conclude that there is not
sufficient evidence to speak of vowels produced in open and closed syllables as separate
allophones.
Morrison (2004) set out to specifically examine the contexts in which Navarro-
Tomás (1918) indicated that close and open allophones of the mid vowels would occur.
One male and one female speaker of a highly educated dialect of Madrid, Spain, took part
in this experiment. Pairs of words which contained the mid vowels /e/ and /o/ in the
contexts in which Navarro-Tomás indicated there would be allophonic variation were
constructed and embedded within a carrier phrase.22 The participants said each of the 24
sentences 10 times in random order. The F1 and F2 of each vowel were measured at the
midpoint, and the frequency values were then converted to a mel scale. The acoustic
measures were then submitted to two different statistical analyses: a cluster analysis and
a discriminant analysis. The first test was chosen in order to determine if the vowels
clustered into distinct groups, thus evidencing separate categories. The Discriminant
analysis was used to determine if the categories identified by the cluster analysis were
differentiated from one another. The results of these analyses did not support the
22 Words were constructed in pairs, such as seca “dry” and secta “sect” in which the /e/ in the former would be expected to exemplify the close [e] and the latter the open [ε]. The words were then embedded into the carrier phrase Pues____ se ha dicho (“Well, ____ she/he said to herself/himself”). The contexts included vowels that were or were not in contact with /r/, /l/, /x/, /p/, /t/, /k/. Examples of vowels in syllables closed by /s/ were not included in this analysis.
62
existence of separate allophones for the Spanish mid vowels. There was considerable
overlap between the supposed allophones of /o/ for the male speaker, indicating a lack of
two separate categories. The analyses of the female’s productions of /o/ and both
speakers productions of /e/ provided slightly more separation which seemed to suggest
there might be a distinction, but Morrison argued that the differences observed might be
better accounted for based on articulatory constraints. Overall, he concluded that the
acoustic data did not support the existence of the allophonic categories described by
Navarro-Tomás.
In terms of vowel duration, Marín Gálvez (1995) reported minimal differences in
vowel length based on syllable type, and more importantly, based on the nature of the
following consonant. His analysis of the vowel duration of two male speakers (see
section 2.2.3.1. for methodological details) indicated that vowels produced in open and
closed syllables did not differ significantly with respect to duration. When the manner of
articulation of the following consonant was examined, however, the results showed that
vowels followed by fricatives in closed syllables were longer than vowels followed by
fricatives in open syllables. The opposite pattern was reported for vowels that occurred
in contact with nasal and liquid consonants. Despite the pattern, however, none of these
differences were shown to be statistically significant. Thus, like the previous studies of
vowel quality, the variability in vowel duration based on syllable structure that was
described by Navarro-Tomás (1918) was not corroborated with acoustic measurements.
The studies reported above indicate that the traditional claim that Spanish vowels
exhibit allophonic variation according to their syllable structure is not borne out by
acoustic data. In other words, although there may be some difference in terms of
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pronunciation for vowels produced in closed and open syllables, especially for the mid
vowels, robust differences suggesting separate categories were not observed in this data.
The previous claims described in this section of the chapter motivate the need to examine
the effect to syllable type on heritage Spanish vowel pronunciation. Although most of
the acoustic research suggests that these speakers will not exhibit significant quality and
quantity differences based on syllable type, HS are also bilingual in English. It is well
accepted that consonantal context affects formant values of vowels produced in English
(Stevens & House, 1963) and Spanish (Guirao & Borzone de Manrique, 1975). Also
generally accepted is that the nature of the following consonant and the syllable structure
affect the duration of English vowels (House & Fairbanks, 1953). Thus, the interaction
of the two linguistic systems may result in HS exhibiting differences in vowel quality and
quantity as a consequence of syllable structure. If, however, HS do approximate native
speaker norms (i.e., native Spanish norms) as is typically argued in the literature, the
close/open mid vowel distinction may be absent.
2.2.3.3 Speech style
As discussed previously, one of the explicit claims in the work of Navarro-Tomás
(1918) is that the quality and quantity of Spanish vowels varies as a function of speech
style. Harmegnies and Poch-Olivé (1992) conducted one of the few studies to directly
examine the effects of speech style on vowel production. The goal of their investigation
was to examine the effect of speech style—either spontaneous or laboratory style—on
centralization and inter and intra-cluster variability: the degree to which the distributions
of the formants within the acoustic space cluster together both within and across speech
styles. Spontaneous speech data were collected from a semi-directed interview
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conducted with one male informant. The participant was described as having an “average
cultural background” and no “marked dialectal accent” (p. 431). The laboratory speech
corpus consisted of words that were selected from the interview and then put into a word
list which was read by the participant. A total of 477 pairs of words, the same words in
both spontaneous and laboratory style, were analyzed. The first (F1) and second (F2)
formant frequencies for the vowels were calculated at the vowel midpoint, along with the
Euclidean distance of each of the vowels from schwa. The standard deviations of the first
and second formant frequencies were also calculated in order to examine the degree of
variability and clustering of each of the vowels within the acoustic space.
The statistical analyses indicated that on average, the vowels /i,e,o,u/ showed
significantly more centralization in the spontaneous speech sample than in laboratory
speech. The vowel /a/ showed the least amount of centralization, and the difference
between the two speech styles for this task was not statistically significant. The front
vowels /i,e/ also exhibited greater degrees of centralization than the back vowels /o,u/.
The analysis of intra-cluster variability revealed that the vowel tokens extracted from the
spontaneous speech task showed greater variability (i.e., were more centralized) than
those that were produced in the controlled speech task. The authors argue that the
differences in clustering between the two speech styles, as well as the varying degrees of
centralization, could potentially be explained by H&H Theory (Lindblom, 1990).23 The
spontaneous speech style may exhibit hypoarticulation, in which the phonetic targets are
undershot, resulting in differences (i.e., centralization) in timbre that are not observed in
the laboratory speech task.
23 H&H theory (Hyper- and Hypoarticulation) is a theory of speech production and perception that will be discussed in greater detail in chapter 5.
65
In addition to the acoustic analyses, the authors also conducted a recognition task
to determine the degree of overlapping of vowel categories in each of the speech styles.
They constructed a recognition task and report that the degree of centralization of a vowel
in the spontaneous speech task is not directly correlated to its rate of recognition. The
high vowels /i,u/ showed high recognition rates and were less confusable in the
recognition task than the vowel /a/, but exhibited greater degrees of centralization. The
vowel /a/ showed the lowest degree of centralization, but was the most highly confused.
Unfortunately, the authors provide virtually no description of the stimulus materials,
procedure, and statistical tests that were carried out in this experiment. For this reason,
these results and their implications should be interpreted with caution.
In a related study, Poch Olivé et al. (2008) reexamined the effect of speech style
on the production of Mexican Spanish vowels. Utilizing the same procedure as they
employed in their 1992 study, 30 tonic, open, examples of all five of the Spanish vowel
phonemes were extracted from a semi-informal interview. These same words were then
repeated later in an isolated context, and the vowels produced in the two speech styles
were subsequently compared. The distance of each vowels from the center of the vowel
space was also calculated using the same methodology employed in their earlier study.
The results of this investigation revealed several important similarities and
differences between the speakers of the two varieties. Like the speaker of Peninsular
Spanish described in Harmegnies and Poch Olivé (1992), the Mexican participant also
exhibited a significant degree of centralization of vowels produced in spontaneous speech
when compared to laboratory speech. A discriminant analysis of the data showed that for
both speakers, greater clarity was maintained between the vowel categories in laboratory
66
speech as compared to spontaneous speech. Comparisons between the two speakers,
however, indicated that the tendencies for centralization and the vowels affected differed.
Whereas the speaker of Peninsular Spanish described in the 1992 study exhibited a
pattern of centralization that corresponded with vowel aperture (i.e., the high vowels
showed the greatest rates of centralization, followed by the mid vowels, and so on), the
Mexican speaker only showed significant degrees of centralization for the non-back
vowels.
An examination of the overall areas of dispersion in laboratory speech revealed
additional similarities and differences between the two speakers as well. Generally
speaking, the vowels were situated in similar areas, but the Mexican speaker produced
high vowels with a more open articulation (i.e., lower) and also showed greater degrees
of overlap between the two back vowel categories. The patterns of reduction (i.e.,
centralization) also differed. Whereas the Peninsular speaker exhibited a proportional
decrease in the size of the acoustic space in spontaneous speech, the Mexican speaker’s
reduction resulted in the four non-low vowels clustering in a very narrow frequency
range. In other words, the Peninsular speaker’s spontaneous speech data maintained the
overall shape of the vowel distribution observed in laboratory speech, whereas the
Mexican speaker showed a greater clustering of /i/, /e/, /o/, and /u/ into a small acoustic
area. The centralization observed in Mexican Spanish was thus not symmetrical or
proportionally equal. The main findings of this investigation thus indicated that vowel
production varies as a function of speech style, but that the type of reduction and
centralization can vary across dialects.
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The previous studies conducted by Harmegnies et al. (1992) and Poch Olivé et al.
(2008), although important and innovative, only presented the results of two speakers.
An additional investigation carried out by Martín Butragueño (2011) revisited the
question of style-induced reduction by analyzing male and female speakers from Mexico
City. He also compared the vowel productions of his speakers to those reported in Servín
and Rodríguez (2001). Four male and four female speakers of Mexican Spanish took part
in this investigation. Five tonic and five atonic examples of each of the five vowels were
extracted from a semi-informal interview, yielding 400 vowels total across all speakers.
The first and second formant frequencies were measured at the center of each vowel. The
comparisons between the speakers in Servín and Rodríguez’s (2001) study and those
obtained by Martín Butragueño (2011) again revealed a robust effect of speech style on
the rate of centralization. The methodology used in the former was more representative
of laboratory speech, thus the distance of the vowels from the center of the space was
greater than those values obtained from Martín Butragueño’s spontaneous speech task.24
These findings support a robust effect of speech style not only across dialects of Spanish,
as reported in Poch Olivé et al. (2008), but also within dialects.
Other than these three investigations, the only other acoustic examination of
speech style effects in Spanish was conducted by Willis (2005). His analysis of bilingual
English-Spanish speakers in the Southwestern United States will be discussed in greater
24 In addition to the findings pertaining to speech style, other important differences emerged. An analysis of the vowel pronunciations of male and female speakers revealed differences in dispersion and overlap. The male speakers, for example, exhibited a considerable degree of overlap between the /i/ and /e/ vowel categories and even more so for the /u/ and /o/ categories. On the other hand, the female speakers exhibited greater degrees of separation of the high and mid vowels, although there was some overlap. The range of F1 and F2 values for the high front vowel /i/ was also found to be much greater for male speakers than for females, but the females showed more variation in their production of /o/.
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detail in section 2.3.1., but the basic findings confirm previous reports that speech style
has a centralization effect on vowel pronunciation.
The overall findings of these aforementioned studies confirm Navarro-Tomás’s
(1918) observation that Spanish vowels have a tendency to reduce in more naturalistic
speech contexts. Thus, in order to provide an accurate and complete description of the
Spanish vowel space, naturalistic and controlled speech samples should be examined in
order to determine how spontaneity affects vowel organization, distribution, and overlap.
As will be explained later on in this chapter and chapter three, this dissertation also
examines the effects of speech style on the production of heritage Spanish vowels. In so
doing, it offers a more complete description of the manner, degree, and type of reduction
and variation that can occur within the system.
2.2.3.4 Dialectal variation?
A final aspect of the Spanish vowel system that needs to be addressed is the claim
that vowel production across Spanish dialects is fairly stable. Interestingly, Navarro-
Tomás (1918) never argued that the pronunciation of Spanish vowels across dialects was
invariant. In fact, little mention of the stability of Spanish vowels appears in the early
investigations of pronunciation. In textbooks such as Hualde (2005), however, it is
argued that the majority of the dialectal variation observed in Spanish occurs with the
consonantal system and not with vowels. As discussed in section 2.2.1., Hualde
specifically mentioned that the quality of vowels across Spanish dialects is very stable
and does not exhibit the type of variation observed in English varieties.
Acoustic and impressionistic examinations of vowel pronunciation present
conflicting results in terms of dialectal stability. The investigation of Morrison and
69
Escudero (2007), for example, seems to confirm that vowel quality across dialects of
Spanish is similar. They examined the pronunciation of vowels as produced by
Peninsular and Peruvian speakers of Spanish, and found very few significant differences
in the productions. Quilis and Esgueva’s (1983) investigation suggested that there could
be slight differences in pronunciation based on dialect, but as no statistical methods were
employed, it was determined that the differences were not robust.
In contrast, O’Rourke (2010), which will be discussed in greater detail later in this
chapter, reported that vowel pronunciation within Peru differed significantly. Her
examination of vowel production in Lima and Cusco revealed significant differences in
dispersion and organization for both groups of Spanish monolinguals and Spanish-
Quechua bilinguals. In a study of monolingual Spanish vowel production in the
Dominican Republic, Willis (2008) observed differences in the acoustic distribution and
degree of overlap of Dominican Spanish vowel categories when compared to those
reported by Quilis and Esgueva (1983). In addition, differences in overlap of vowel
categories produced by each speaker were revealed, providing further evidence for
variability in vowel productions across speakers as well as across dialects. Poch Olivé et
al. (2008) also noted differences between Peninsular and Mexican Spanish not only in
terms of overall organization, but also with respect to the manner in which the vowels in
each variety centralized in spontaneous speech. Finally, even the earliest impressionistic
studies of Mexican Spanish conducted by Matluck (1952) and Lope Blanch (1972)
indicated that vowels produced in central Mexico differed from the traditional
descriptions of Peninsular vowels provided by Navarro-Tomás (1918).
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Thus, the assumption of dialectal invariance in terms of vowel quality may have
resulted in the comparative lack of investigations of Spanish vowels. The assumption of
stability, however, could have also been a misinterpretation. It is perhaps not that
Spanish vowels exhibit little variation in quality across dialects, but rather that,
comparatively speaking, they do not vary as much as the dialects of American English.
Although the present investigation will not examine any cross-dialectal distinctions, the
finding that vowel quality differs in some dialects indicates that the vowel system of
Spanish may vary more than previously believed.
2.2.3.5 Summary of acoustic investigations
To summarize the findings discussed above, a number of acoustic investigations
of Spanish vowels have supported and refuted some of the claims put forth in the
impressionistic literature. With respect to lexical stress, there is evidence of reduction in
terms of quality and duration in Spanish, but Delattre (1969) proved that Spanish showed
the least amount of unstressed vowel reduction when compared to three other languages.
Marín Gálvez (1995), however, did report significant differences in vowel duration, with
atonic vowels exhibiting significantly shorter duration than tonic vowels. Finally, an
investigation by Delforge (2008) indicated that at least for Andean Spanish, “reduction”
of unstressed vowels might be better described as devoicing.
The investigations of syllable type and speech style both refute and support
traditional descriptions of the Spanish vowel system. In terms of syllable type, the
majority of the acoustic investigations (e.g., Morrison, 2004; Servín & Rodríguez, 2001)
did not find acoustic evidence of separate mid vowel categories. Their findings conflict
with Navarro-Tomás’s (1918) detailed description of quality differences based on
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syllable type and surrounding context. The investigations of speech style, however,
support Navarro-Tomás’s observation that vowels produced in rapid, conversational, and
naturalistic speech samples tend to reduce and centralize when compared to more
emphatic, slow speech. The series of studies by Harmegnies and Poch-Olivé (1992),
Poch- Olivé et al. (2008) and Martín Butragueño (2011) all provided robust evidence of
centralization in spontaneous speech when compared to laboratory speech that was
elicited in a controlled context. Their findings are critical, because with the exception of
their three investigations and that conducted by Willis (2005), most investigations of
Spanish vowels have focused on very controlled speech samples. Many studies involved
the examination of isolated vowels or words, nonce words, or vowels produced in carrier
phrase tasks. That Harmegnies and Poch-Olivé, Poch- Olivé et al. and Martín
Butragueño have found significant differences in vowel production in controlled and
spontaneous speech samples indicates the need to examine more than one type of speech
style. Examining vowels that were produced in speech of varying levels of spontaneity
offers a more complete and potentially more accurate picture of the vowel system of a
certain speaker or speakers.
Finally, although not discussed in great detail, the general assumption that there is
considerable stability in vowel quality across dialects is only partially supported by the
acoustic data. Whereas some investigations reported only minimal differences across
speakers of different dialects (Morrison & Escudero, 2007; Quilis & Esgueva, 1983),
others indicated that Spanish vowels do vary regionally (O´Rourke, 2010; Poch Olivé et
al., 2008). Thus, although the Spanish vowel system may not exhibit as much variation
cross-dialectally as does English, most researchers appear to recognize that differences do
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exist. That there is some variability in vowel production across dialects indicates that the
pronunciation of the “simple, stable, five-vowel system” may not be as simple and stable
as previously believed.
2.3 Bilingual and contact vowel systems
The goal of this section of the chapter is to present the findings of several studies
of bilingual Spanish and English vowel systems. Section 2.3.1 reviews several studies
pertaining to the pronunciation of Spanish vowels by different groups of Spanish-English
and Spanish-Quechua bilinguals. Section 2.3.2 presents several important research
studies of Chicano, Mexican American, and Mexican Heritage English vowels in two
main regions within the United States.
2.3.1 Bilingual and contact Spanish vowel systems
In addition to studies of monolingual Spanish vowels, several investigations have
examined the acoustic properties of vowels produced by bilingual speakers. With the
exception of O’Rourke (2010) who examined Spanish-Quechua bilinguals in Peru, the
other notable studies focus on Spanish-English bilingual adults and children living in
different regions in the United States.
O’Rourke’s (2010) investigation of Peruvian Spanish vowels had three main
goals. The first was to determine if there was evidence of dialectal variation in Peru by
examining the vowel pronunciation of speakers from two different cities: Lima and
Cuzco. The second goal was to assess the potential influence of Quechua on Peruvian
Spanish vowel pronunciation. The third and final objective was to examine if bilingual
speakers of Spanish and Quechua organized their vowel space differently than
monolingual speakers in the two cities. In order to achieve these three goals, four groups
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of participants took part in this study, with three speakers in each group: native speakers
of Spanish from Lima, native speakers from Cuzco, bilingual speakers from Cuzco who
began learning Spanish and Quechua before entering school (referred to as bilinguals),
and native Quechua speakers who began learning Spanish after starting school (referred
to as learners). All participants were male speakers who were born in either Lima or
Cuzco, and were between the ages of 20-39. The vowel production data were collected
from a read corpus of sentences that was originally designed to assess intonation.
Participants were given index cards containing questions and answers written on them
that were associated with characters in a map task. The 28 sentences were read twice by
each of the twelve speakers, yielding 672 total vowels. All tokens were monophthong
vowels with penultimate stress, with the exception of /u/ which had antepenultimate
stress. The F1 and F2 values of each vowel were measured at the midpoint. Then the
values were converted to a Bark scale, and finally normalized following a procedure
described in Guion (2003).25
The first set of results of the statistical analyses revealed that that all speakers
showed a five-vowel distinction in terms of both height and backness, regardless of
dialect region or language background. The majority of the participants did not
distinguish mid vowel /e/ and the high vowel /u/ with respect to height. Several speakers
also failed to produce a distinction in backness for /o/ and /u/, with the latter occupying a
position more fronted in the acoustic space than the /o/. Based on these preliminary
analyses, O’Rourke concluded that Peruvian Spanish back vowels /o/ and /u/ are
25 As described by O´Rourke (2010), the first three formants were extracted and converted to a Bark scale. She explains that “for each speaker, a k-factor was calculated as a ratio of the average F3 value for /a/ (in Bark) for one specific speaker (S1) divided by the average for each individual speaker (Si). The k-factors for Lima and Cuzco speakers range from 0.97-1.11…Then the F1 and F2 values for all vowels for each speaker were multiplied by the k-factor for that speaker” (p.22).
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considerably lower in height than what has been described for other Spanish dialects.
She argued that the position of the /u/ and its occasional fronting may result that /a o u/
are primarily distinguished in terms of height and not backness.
Despite these similarities, several notable differences between the monolingual
speakers from the two different regions were found, as well as differences between the
monolingual, bilingual, and learner groups in Cuzco. Comparisons across the regions
indicated that the /i/ was articulated higher for the Cuzco speakers than for the Lima
speakers. The pronunciation of /i/, /e/, and /a/ by the speakers in Cuzco were farther front
than those produced by the speakers from Lima. As a result, the speakers in Lima
exhibited vowels that were less dispersed and occupied a smaller portion of the acoustic
space when compared to the speakers from Cuzco. The comparisons between the
monolingual, bilingual, and Spanish learners revealed that the productions of /i/ and /u/
were lower for the Cuzco bilinguals than for the native Spanish speakers and Spanish
learners in this region. An additional important finding was that the bilingual speakers in
this region shared characteristics with both the native and the L2 systems, forming a
hybrid of the two. They produced /a/ and /u/ similarly to the native Spanish speakers, but
produced /e/ in the same acoustic region as the L2 speakers.
Combined, the results presented in O’Rourke (2010) indicate that not only does
the Peruvian vowel system differ from the standard description of Spanish vowels, but
that there was also variation within the country. Cuzco and Lima speakers pronounced
the vowels differently and exhibited different rates of dispersion and organization when
compared statistically. The comparison between the monolingual, bilingual, and Spanish
learner groups revealed the largest differences in pronunciation between the learners and
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the natives. In contrast, the bilingual speakers shared characteristics of both vowel
systems, resulting in a modified and unique configuration not found in the other varieties.
Thus, these results support the presence of dialectal variation in Spanish vowel
production, as well as significant differences in pronunciation based on linguistic
experience.
Shifting focus to bilingual varieties in the United States, Willis (2005) conducted
an acoustic analysis of the Spanish vowels in the Southwestern United States (hereafter
SWS). The goals of his study were to provide an acoustic description of this bilingual
variety using data from a narrative, and also to examine the effect of lexical stress on the
low vowel /a/. The participants in the study were four female bilingual speakers of SWS
who had learned Spanish at home and began learning English upon entering elementary
school.26 The narrative task involved a retelling of Mercer Mayer’s picture story Frog,
where are you?. They also participated in an interview in which they spoke of their
experiences with Spanish, situations that resulted in fear or happiness, a discussion about
their family, and an additional reading task. The first five occurrences of /i e a o u/ in
tonic, open syllables were extracted from the narrative data. Additional tokens of /a/ in
atonic open syllables were extracted to analyze the effect of lexical stress on vowel
production. The F1 and F2 values at the midpoint of each vowel were extracted.
The mean formant values of SWS speakers were calculated and then compared to
the values obtained for Mexican speakers by Quilis and Esgueva (1983). Although no
statistical analyses were conducted, the visual representation of the vowels produced by
26 The description of the participants in Willis’s (2005) study sounds very similar to the definition provided earlier in this chapter for heritage speakers. Willis does not refer to his participants as HS. He does explain that they spoke 40% English and 60% Spanish beginning in high school up until the time they were interviewed. Additional demographic and instructional information is not provided in his study.
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both speaker groups revealed considerable differences between the systems. The SWS
front vowels /i/ and /e/, for example, were produced lower and slightly farther front than
those reported in Quilis and Esgueva (1983). In addition, the SWS /a/ was lower and
produced farther front than what is typically described for the Spanish vowel system.
Interestingly, the /o/ category for the SWS speakers overlapped with the /a/ category for
the monolingual Mexican Spanish speakers. Last of all, the SWS /u/ was articulated
farther front than the monolingual productions reported in Quilis and Esgueva (1983),
and lower than previously described. The analysis of the production of /a/ in tonic and
atonic position revealed that only one speaker exhibited a significant difference in
production based on lexical stress. Given this result, Willis concluded that lexical stress
did not play a significant role in the production of /a/ in SWS, even though the
participants in his study were bilingual. There was no evidence that the unstressed tokens
of /a/ had moved to a location approximating the English schwa. Thus, there appeared to
be no direct transfer of a lexical stress effect from English.
The results of the visual comparison indicated that the SWS vowel system
differed from descriptions presented in the impressionistic literature as well as from the
monolingual system presented in Quilis and Esgueva (1983). Willis argued that these
differences (i.e., fronting of all vowels and overlapping of categories) indicated that the
Spanish vowel system exhibits more variation in quality than previously described. In
addition, a comparison of the narrative data to controlled speech data for the same
speakers collected in a pilot investigation revealed that SWS vowels were more
centralized in the narrative speech style than in a carrier phrase. This finding is
consistent with previous research conducted by Harmegnies and Poch-Olivé (1992) that
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showed greater degrees of centralization in spontaneous speech. Finally, the lack of a
stress effect observed for SWS /a/ suggested that the bilingual speakers of this variety
were not integrating characteristics of English pronunciation into their vowel
pronunciation, at least not for that particular vowel. All in all, this study presented
evidence for variation within the Spanish vowel system across varieties and across speech
styles.
Another important study of Spanish-English vowel pronunciation was conducted
by Menke and Face (2010). Their investigation examined the pronunciation of Spanish
vowels by L2 learners of Spanish at different levels, paying specific attention to the effect
of lexical stress on pronunciation. Sixty native English speakers participated in this study
who were divided into three equal groups based on their level of language instruction:
fourth semester Spanish learners, graduating Spanish majors, and Ph.D. students in
Spanish. Six native speakers of Spanish were also a part of this study, three of which
were from Spain, two from Mexico, and one from Colombia. Although this participant
group is labeled “native” by Menke and Face, they were actually bilingual in English and
some had been speaking or studying English for as many as 20 years. All participant
groups first completed a language background questionnaire, followed by an oral reading
of the Spanish story Aniversario by Luis Romero. The text was modified slightly so that
there were sufficient examples of atonic and tonic vowels. One hundred tokens (20
tokens of each of the five Spanish vowels) were analyzed for each speaker that were
balanced across stress context (tonic and atonic) and syllable type (closed and open). The
F1 and F2 values of each vowel were measured at the midpoint.27
27 The text, Aniversario, is not included in the appendix, therefore it is not possible to examine if the vowels analyzed in Menke and Face’s (2010) study were balanced by consonantal context. This study also only
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Overall comparisons of the three learner groups revealed differences in F1 and F2
frequencies according to level of instruction. The lowest level of learners (i.e., fourth
semester) produced vowels with F1 values that were significantly higher (i.e., lower
vowels) than those produced by the speakers in the other two groups. The fourth
semester learners also produced the front vowels with lower F2 values when compared to
the other two learner groups, resulting in /i/ and /e/ that were farther back in the vowel
space. The reverse pattern was observed for /u/, which was produced by the fourth
semester learners with a higher F2 value resulting in a more fronted articulation. The
fourth semester learners, thus, exhibited a reduced and lowered vowel space when
compared to the other two participant groups. The analysis of the native speaker vowel
productions indicated that neither of the two advanced participant groups differed
statistically form the natives. The results of the first set of statistical analyses thus
indicated that the higher the learner level, the more expanded the space. As learners
moved from the fourth semester onto more advanced levels of instruction, their vowel
pronunciations began to more closely approximate the articulations of a native speaker.
The analyses of lexical stress indicated that learners at all levels exhibited some
differences in the articulation of stressed and unstressed vowels. The only vowels
affected in the fourth semester learners’ speech were /a e u/. The atonic /a/ was produced
higher and farther front. Atonic /e/ and /u/ exhibited lower and higher F2 values,
respectively, resulting in all three vowels moving towards the center of the vowel space.
The graduating Spanish majors produced atonic /a/ higher and farther front than tonic /a/,
their production of atonic /i/ was produced lower and farther back, and the tokens of
examined F1 and F2 formant values, and did not examine vowel duration. As will be described in greater detail in chapter 5, the only study to the best of my knowledge that examines L2 Spanish learner vowel duration is Stevens (2011).
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atonic /e/ and /o/ in atonic syllables were more centralized than the tonic productions.
The Ph.D. students exhibited a similar pattern, again with /a/ higher and farther front
when atonic, and /o/ was articulated higher. The front vowels /i/ and /e/ and the back
vowel /u/ exhibited F2 values that were more centralized. For the latter two learner
groups, then, the effect of lexical stress was greater along the F2 dimension, yielding
atonic vowels that were more centralized than their tonic counterparts. Even though most
descriptions of the Spanish vowel system argue for the absence of differences in vowel
quality based on lexical stress, the native speakers also exhibited some differences. The
only vowels affected, however, were /e/ and /u/, both of which were more centralized in
atonic productions than tonic.
The results of Menke and Face’s (2010) investigation revealed two important
characteristics of L2 Spanish learner and native speaker vowel production. The first is
that as a learner’s level of proficiency increased, their vowel space became more
expanded and more like that of a native speaker. In addition, the examination of lexical
stress demonstrated that learners at all levels of proficiency, as well as the native speakers
of Spanish in this investigation, showed some degree of centralization of unstressed
vowels in Spanish. The effect of lexical stress was strongest along the F2 dimension,
indicating that stress had a greater impact on the frontness or backness of the vowels and
less effect on their height. The differences in vowel quality based on lexical stress
became less extreme as the level of proficiency increased. As learners gained more
experience with the language, the influence of the English stress distinction was lessened
in the production of their Spanish vowels. Menke and Face’s study thus indicates that
lexical stress is a factor affecting the production of learner Spanish vowels, especially at
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lower levels of proficiency. It also indicates, however, that previous accounts of the lack
of stress effects in Spanish may not hold true for all speakers and speaker populations.
A final and very recent acoustic investigation of bilingual vowel production in the
United States was conducted by Alvord and Rogers (2011). The goals of their study were
to determine if Miami Cuban Spanish exhibited unstressed vowel centralization, if the
English vowels /æ/ was integrated into the system of these speakers, and if vowel
pronunciation varied according to speech type. Six male and five female speakers of
Miami Cuban Spanish participated in this study, and were further divided into first,
second, or third generation speakers based on their age of arrival to the United States.28
The vowel production data were gathered from three speech tasks: a read word list, a
read story and comprehension questions, and a sociolinguistic interview. The first and
second formant frequencies of English and Spanish vowels extracted from the tasks were
measured at the midpoint. The formant measures were then normalized in order to
compare across genders. The differences between tonic and atonic vowel productions
were compared statistically via paired-samples t-tests.
Alvord and Rogers reported that Miami Cuban bilinguals exhibited differences in
vowel quality based on lexical stress, regardless of their generation.29 They observed that
in atonic syllables, /a/ was raised, /i/ and /e/ were backed, and /o/ was fronted. A
comparison of their English and Spanish vowel pronunciation revealed that this group of
bilinguals did not integrate characteristics of English into their Spanish. In fact, they
28 The first generation speakers (two males and one female) were born in Cuba and immigrated to the United States after age eleven. The 2nd generation group consisted of two male and two female speakers who immigrated to the United States before the age of six years or were born to a first generation parent. The 3rd generation group consisted of two male and two female speakers who were born to at least one 2nd generation parent. 29 Alvord and Rogers (2011) did not analyze vowel duration in their study.
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found evidence of Spanish influence on their English vowel productions, especially with
the pronunciation of the vowels /æ/ and /ɑ/. Some speakers in the first generation did not
exhibit a lax/tense distinction with the front vowel /i/. In terms of task type, the overall
acoustic space of the vowels became more reduced as the speech style became less
formal. The vowels produced in the wordlist task were the most peripheral, the story task
resulted in vowels that were somewhat centralized, and the vowel tokens extracted from
the sociolinguistic interview were the most centralized. These findings are consistent
with Menke and Face (2010) who reported unstressed vowel centralization in Spanish for
learners and native Spanish-speaking bilinguals. In addition, the centralization effect
observed for spontaneous speech is consistent with several investigations of speech style
on vowel pronunciation (Hamegnies & Poch-Olivé, 1992; Poch-Olivé et al., 2008; Willis,
2005). Alvord and Rogers thus conclude that their investigation supports the notion of
variation and unstressed vowel centralization in Spanish based on stress context and
speech style.
The investigations of bilingual Spanish vowel pronunciation presented above
indicate a number of important characteristics about bilingual vowel systems. The first
and most important observation is that bilingual vowel systems are not identical to
monolingual varieties in the same dialect region. O’Rourke (2010) reported differences
between monolingual and bilingual speakers of Spanish and Quechua in Peru, and Willis
(2005) and Menke and Face (2010) observed that Spanish-English bilinguals differed
from the monolingual Spanish norms as well. These findings suggest a modified system
of pronunciation for bilinguals that often exhibits characteristics from both of the
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bilinguals’ languages.30 It is important to note, however, that a bilingual may not
integrate characteristics of the majority language (i.e., English) into their native system.
Alvord and Rogers (2011), for example, reported that not only did Miami Cuban
bilinguals not integrate characteristics of their English pronunciation into their Spanish,
but that the reverse was observed with the low vowels /ɑ/ and /æ/.
A second important finding is that factors which are argued to not affect or not be
present in monolingual varieties of Spanish are often observed in a bilingual speaker’s
pronunciation. Lexical stress, for example, was shown to affect the Spanish vowel
pronunciations of L2 learners and Spanish bilinguals (Menke & Face, 2010). Atonic
vowels were found to centralize, especially along the F2 dimension, for these speakers,
whereas most monolingual varieties of Spanish do not exhibit such variation based on
lexical stress. Alvord and Rogers (2011) also reported stress effects in Miami Cuban
Spanish, with atonic vowels moving more towards the center of the space when
compared to the tonic productions.
The overall usage of the acoustic space and dispersion of vowels within the space
was also shown to vary as a function of linguistic experience. O’Rourke’s (2010) study
reported that monolingual and bilingual speakers of Spanish and Quechua showed
different rates of dispersion based on the age at which they began learning their second
language. Menke and Face (2010) also showed differences between L2 learners of
different levels, with the most advanced learners producing vowels that occupied the
largest acoustic area. Finally, Alvord and Rogers noted generational differences in vowel
30 The bilingual system s are “modified” in the sense that they differ from the acoustic description provided by Quilis and Esgueva (1983).
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production, indicating that experience and length of exposure to the majority language
within a region can induce changes in a speaker’s L1 system.
A final important finding from these studies is that speech style was found to
affect bilingual vowel pronunciation in much the same way as it affects monolingual
vowel production. Alvord and Rogers (2011) found that as the spontaneity of speech
increased, vowels had a greater likelihood of centralizing. Willis (2005) reported similar
results for bilingual Spanish in the Southwestern United States. Thus, speech style has
robust and consistent effects on vowel pronunciation in bilingual varieties of Spanish as
well as monolingual varieties.
2.3.2 English vowel systems of heritage Spanish speakers
The investigations described above indicate that bilingual speakers of English and
Spanish, and also of Spanish and Quechua, pronounce Spanish vowels differently than
Spanish monolinguals. Some varieties exhibit different rates of dispersion of vowels,
whereas other bilingual Spanish varieties are characterized by notable differences in
production as a consequence of lexical stress. These findings support the need for an
examination of heritage Spanish vowels, and suggest that these speakers, too, will exhibit
a modified vowel system when compared to previous descriptions. Although no studies
of HS Spanish vowels in Chicago have been conducted to date, several important
investigations have analyzed the pronunciation of Mexican Heritage English (also
referred to as Chicano English, Mexican American English, or non-ethnic English) in
Southern California and the Midwestern United States. These studies offer insight into
how English-dominant bilingual speakers integrate characteristics of the majority dialect
into their speech, which characteristics of the Spanish system may remain intact in their
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system, and how the minority communities’ relationship with the majority speakers
impacts their English pronunciation.
Godiñez and Maddieson (1985) analyzed the vowel duration and quality of
Chicano English speakers in Eastern Los Angeles, California. The participants in this
study consisted of 15 speakers of Chicano English who had little knowledge of Spanish,
15 Spanish/English bilinguals from the same area, and 15 speakers of General California
English who attended a neighboring high school in Los Angeles. All participants were
male and were in the 11th grade, ranging from 16 to 17 years of age. In order to analyze
vowel duration and quality, the participants were asked to read aloud a list of /hVd/
words embedded within a carrier phrase, in which the vowel represented one of the
phonemes present in American English. Two repetitions of each phrase were produced
by each participant. The total duration of the vowel and the F1 and F2 frequencies
measured at the steady-state portion were analyzed. The difference between F2-F1 was
also calculated, as this measure has been argued to provide a more accurate perceptual
dimension for vowel backness.
The analysis of duration showed no significant overall effect of group and no
significant interactions, although the Chicano English speakers showed a smaller range of
duration between the long and short vowel phonemes in English. This difference in
durational range, however, was not found to be statistically significant. In terms of vowel
quality, however, several important differences were reported. Three separate
comparisons were conducted: Chicano bilinguals vs. Chicano monolinguals, Chicano
monolinguals vs. General California English speakers, and Chicano bilinguals vs.
General California English speakers. For the first comparison between the Chicano
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groups, the bilinguals tended to produce vowels that were lower than the monolinguals.
In addition, the front vowels produced by the Chicano monolingual group were slightly
farther back than those produced by the Chicano bilingual group. When comparing the
Chicano monolinguals to the General California English speakers, the Chicanos had a
higher F1 for all vowels other than /i/ and /u/ than the General group. For the Chicano
monolinguals, /u/ was produced farther back in the acoustic space than in General
California English, but the non-back vowels were produced farther front. Finally, the
comparison between the Chicano bilinguals and the General California English speakers
showed that /I ε æ/ were produced higher by the bilingual speakers, but /i/ and /a/ were
produced lower. The back vowels /ʊ/ and /u/ were produced farther back for the
bilingual speakers, but the other vowels were produced farther front when compared to
the General California pronunciations. Overall, Godiñez and Maddieson (1985) conclude
that the Chicano monolinguals produced vowels higher than the bilinguals, and that their
vowels were more similar to those produced by the bilinguals than they were to the
General California English pronunciation. Both of the Chicano groups produced /ʊ/ and
/u/ farther back in the vowel space relative to the English variety, which the authors argue
may be due to the influence of Spanish. In the end they conclude that Chicano English
“represents an “autonomous social dialect with distinct characteristics passed on by the
usual processes of linguistic transmission (p. 57).”
A subsequent study also focusing on California English was conducted by
Fought (1999). The goals of her study were to first determine if members of the minority
Latino community were integrating a majority sound change -- /u/-fronting – into their
speech (i.e., their Latino variety of English), and second to identify the sociolinguistic
86
factors connected with the presence or absence of this pronunciation. The fronting of the
vowel /u/ has been attested in general California English, but at the time of Fought’s
investigation, no study to date had analyzed the extent to which speakers of Latino
English were integrating this characteristic into their speech. Fought conducted
sociolinguistic interviews in English with 32 Latino young adults residing in western Los
Angeles. Many of the participants had also attended an alternative high school called
Westside Park, and had some affiliation, connection, or contact with Latino gangs in the
area. The pronunciation of the /u/ was examined by extracting as many tokens as
possible of this vowel from the interview data and measuring the first and second formant
frequencies.31
An examination of the data revealed that the Latino English speakers did exhibit
/u/-fronting in their speech, but that there was a considerable amount of variation in terms
of the degree of fronting. Some speakers fronted the /u/ such that it almost overlapped
with the space for the front vowel /i/, whereas others produced no significant fronting at
all. A second component of her analysis was to examine which social factors influence
the presence or absence of /u/-fronting in this minority community. She included
traditional social variables such as gender, age, and social class, but also included a
measure of gang-affiliation. The results of this analysis revealed that no single social
factor alone produced a clear pattern of /u/-fronting; that is, there was no clear,
observable tendency for males or females, middle or lower class speakers, or gang
members/gang affiliates and non-gang affiliates to produce a fronted /u/. Interactions
between these social factors, however, did reveal trends. She found a pattern that
31 Fought (1999) states that she extracted as many tokens as possible of the peripheral vowels /i/, /u/, /ɑ/ and /æ/ from the interview data. She extracted the tokens “well into” the interview “in order to access the most vernacular speech style.” She does not indicate how many total vowel tokens she analyzed.
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differed for men and women based on the conjunct of social class and gang-affiliation.
Non-gang affiliated women overall favored /u/-fronting, but when social class was
factored in to the gang-affiliated group, the working and lower class speakers disfavored
/u/-fronting whereas the middle class gang-affiliated women favored it. The pattern for
men was a mirror image of that observed for women. The gang-affiliated men overall
disfavored /u/-fronting, whereas the non-gang-affiliated members differed according the
social class. The working and lower class non-gang affiliated men disfavored /u/-
fronting, but the middle class favored it.
The results of Fought’s (1999) investigation emphasized the importance of
including non-traditional sociolinguistic variables into these types of investigations.
Including measures of group affiliation and ties to certain networks (i.e., gang-affiliation)
revealed a trend that was otherwise difficult to observe. Her study also showed that
speakers of minority communities do integrate characteristics of majority sound changes
into their speech. The presence or absence of /u/-fronting was perhaps one way in which
individual speakers could signal their identity and membership in a specific community.
The results of Fought conflict slightly with the results of Godiñez and Maddieson (1985),
who showed that Chicano monolingual male speakers did not exhibit noticeable degrees
of /u/-fronting; their productions of /u/ were backed relative to the General California
English speakers, approximating the values of those produced by the Chicano bilinguals.
The lack of /u/-fronting in Godiñez and Maddieson’s study, however, may be attributable
to the social characteristics of the participants. If all participants were non-gang members
of the working or lower class, then according to Fought’s description this group of
speakers would not front the /u/. Regardless, the results of these two studies demonstrate
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that /u/-fronting, a majority characteristic, does exist in a non-white community in Los
Angeles, and that the degree to which this phenomena occurs may be due in part to a
speaker’s speech community and other social characteristics.
In addition to studies of Chicano and Latino pronunciation in California, three
recent investigations have also examined the vowel pronunciation of Mexican Heritage
English speakers in portions of the Midwestern United States. Roeder (2010), for
example, analyzed the pronunciation of the English vowels by Mexican American
speakers living in Lansing Michigan—an area of the United States known to exhibit the
Northern Cities Vowel Shift (NCSV). Lansing presents as an interesting case of
linguistic diversity, however, in that not only are Mexican Americans exposed to the
standard Anglo variety, but also have contact with Tejano English from the migrant
population that passes through the area. In addition, many of the Mexican Americans in
Lansing lived in Texas and were exposed to Tejano English prior to moving to Michigan.
For this reason, Roeder wanted to determine if the Mexican American speakers living in
Lansing Michigan exhibited characteristics of Tejano English, or if they had adopted the
NCSV observed in the speech of Anglo-Americans.
The participants in this study included six female speakers of Mexican American
English between the ages of 14-22, eight older (26-45) male speakers of Mexican
American English, and 12 young-adult Anglo speakers of English from Lansing. Each
speaker read a list of 107 English words, 77 of which contained target vowels that were
all tonic. The F1 and F2 were measured at the midpoint of each vowel, and the Lobanov
method of normalization was performed in order to compare across gender. The tokens
of /æ/ were analyzed separately for those in prenasal versus nasal position based on
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previous research indicating that the pronunciation of this vowel was affected by nasality.
The pronunciation of Tejano English vowels were based off of data presented in Thomas
(2001), and no Tejano speakers actually participated in this experiment.32
The analyses of the F1 and F2 values indicated that the Mexican American
speakers’ vowel productions were very similar to those produced by the Anglo speakers
in that they exhibited many characteristics of the Northern Cities Vowel Shift (NCSV).
In particular, they had established separate categories for the lax vowels that were shifted
in the direction expected for the NCSV, and exhibited a closeness of the vowels /æ/ and
/ε/. The proximity of these two vowels in the Mexican American speech indicated that
their variety was more similar to the Anglo English dialect than to Tejano English. It was
concluded that these characteristics indicated a high degree of accommodation to the
majority (i.e., Anglo) norm of vowel pronunciation by these speakers.
Despite the overall similarity between the systems, there were considerable
differences observed between genders and for the production of /æ/ in prenasal and
nonprenasal positions. The females exhibited more advanced stages of the NCVS when
compared to men, as evidenced by their greater degree of lowering of /I/ and backing of
/ε/. In addition, the pronunciation of the /æ/ in prenasal and non-prenasal positions
differed for men and women, and also between the Mexican American speakers and the
Anglo speakers. While the Mexican American women exhibited lower F1 values for the
32 Thomas (2001) provides further information pertaining to the characteristics of the variety of Mexican American English spoken in Laredo, Texas. Some of his findings are consistent with the studies conducted on California and Midwestern varieties of Mexican American English. He argued that the variety of English spoken by the speakers he investigated showed the influence of Spanish in their English, such that /o/, /u/, and /ʊ/ remained as back vowels—which conflicts with Fought’s (1999) study. He also reported that many of the Mexican American speakers did not distinguish between the front and back tense and lax vowels /e/, /ε/, /u/, /ʊ/. He also argued that these speakers had a tendency to merge /ɔ/ and /ɑ/ such that the resulting vowel is farther front than the Anglo Americans who also exhibit this merger. Finally, he indicated that these speakers did not exhibit a lowering or retraction of /æ/ as had been observed in some of the younger Anglo speakers in the same region.
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prenasal /æ/ that were in line with the Anglo speakers’ productions, they failed to show
the distinction in F2. That is, although their productions of /æ/ before nasals were
significantly higher than the same vowel in other consonantal contexts thus
approximating that of Anglo females, they were not as far front as would be expected for
advanced stages of the NCSV. The Mexican American men showed almost no
accommodation to this characteristic of the NCSV. This research confirmed previous
arguments that women are more likely to accommodate to the standard variety, whereas
men and older speakers have been found to resist conforming to the regional norm. In
addition, the Mexican Americans showed differences in their production of /æ/,
indicating that their variety of English was still somewhat distinct from the majority
variety spoken in Lansing.
Two additional studies conducted on Mexican Heritage English pronunciation
were conducted by Konopka and Pierrehumbert (2008, in press). The goal of their first
(2008) study was to compare and contrast the English vowel pronunciation of Mexican
Heritage English speakers, L2 English speakers, and monolingual English speakers of the
Midland dialect. Mexican Heritage English speakers were defined as speakers whose
parents had emigrated from Mexico, but who were born in the United States and formally
educated in the Chicago school system.33 The L2 English speakers were English learners
of Mexican descent. The monolingual English (“non-ethnic”) control data was taken
from a study conducted by Hillenbrand et al. (1995), and contained the productions of the
English vowels of 48 adult females. The Mexican Heritage English participants (10
33 To clarify, the Mexican Heritage English (MHE) speakers in Konopka and Pierrehumbert’s investigations were native English speakers of Mexican heritage who were formally educated in English. Thus, the term “heritage” therefore refers to the speakers’ background, and not the manner in which they acquired English.
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female) and L2 English participants (11 female) read out loud English words from a
wordlist that contained the 11 English vowels embedded in a CVC context. The list
consisted of 179 individual words, but once vowels in prenasal and preliquid contexts
were eliminated, the total number of words utilized was 92. The overall vowel duration
was measured for each vowel, as well as the F1 and F2 frequencies at the midpoint.
The analysis of the L2 English speakers revealed that they exhibited significant
overlap among the high and back vowels, not producing distinctions between /I/ and /i/
and /ʊ/ and /u/. The production of /æ/ for this group was found to be closer to the
Spanish /a/, evidencing the influence of the five-vowel system of Spanish. The Mexican
Heritage English speakers, however, showed the separation of categories into distinct
tense and lax vowels. Their /i/ and /u/ were raised and fronted relative to the non-ethnic
English variety (i.e., Anglo English). Their productions of the lax vowels /I/ and /ʊ/ were
lower than those produced by the Anglo speakers. The raising and fronting of the high
tense vowels and lowering of the high lax vowels resulted in a greater separation of the
tense/lax distinction. The greatest difference between the Mexican varieties of Spanish –
both the L2 English speakers and the Mexican Heritage English speakers – was the
pronunciation of /æ/. In the non-ethnic variety, the /æ/ was fronted, indicating the
presence of the NCVS. The Mexican English speakers, however, did not exhibit
fronting. Konopka and Pierrehumbert (2008) conclude that Mexican Heritage English
speakers in Chicago do not participate in the NCVS but rather have established their own
variety characterized by the raising of /i/ and /u/ and lack of /æ/-fronting. They argue that
“insular, close knit communities are more likely to maintain dialects distinct from the
larger regional population in which they are situated” (p.100).
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In a related study, Konopka and Pierrehumbert (in press) re-examined Mexican
Heritage English vowel pronunciation, focusing not only on the static qualities of vowels
(F1 and F2 at the midpoint of the vowel) but also the dynamic properties of the vowel
system (vowel inherent spectral change, duration ratios between long and short vowels).
The goal of this study was to compare and contrast Mexican Heritage English, Anglo
English, and L2 English, as well as determine which properties, either static or dynamic,
contributed to the perception of a foreign accent. They analyzed the speech of four
different participant groups: 14 female speakers of Mexican Heritage English, 12 female
second-language learners of English, 12 female Anglo speakers, and 7 native Spanish
speaking females from Mexico.34 All speakers resided in the Albany Park Neighborhood
in Chicago. The English speaking participants (i.e., all but the Mexican natives) read out
loud English words from a wordlist that contained the 11 English vowels embedded in a
CVC context—the same instrument used in Konopka and Pierrehumbert (2008). The
Spanish-speaking participants (i.e., all but the Anglo speakers) read a Spanish wordlist
composed of the five Spanish vowels embedded with CVCV contexts in which the
surrounding consonants were always /p b t d/. Each word was repeated five times. The
formant frequencies of the English and Spanish vowels were then measured at the 20%,
50%, and 80% points throughout the vowel, and duration measures were calculated.
In their comparison of the varieties, they reported that the Mexican Heritage
English speakers exhibited a well-differentiated vowel system that was very similar to
34 The Mexican Heritage English speakers who participated in Konopka and Pierrehumbert (in press) have a similar profile to those who completed their 2008 study. As described earlier, Mexican Heritage English speakers were defined as speakers whose parents had emigrated from Mexico, but who were born in the United States and formally educated in the Chicago school system. The L2 English speakers were English learners of Mexican descent who were recruited from the advanced-level ESL courses. The Anglo English speakers were native speakers of the Inland North dialect. The monolingual Spanish speakers were recruited from beginning level ESL classes and most were from Michoacán, Mexico.
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that of the Anglo English speakers. In contrast, the L2 English speakers did not exhibit a
well-differentiated English vowel system, collapsing the tense/lax vowel categories as
described for Konopka and Pierrehumbert (2008). In addition, the L2 English lacked a
long/short distinction between vowels in terms of duration. This durational characteristic
of the L2 vowels was more similar to that of the monolingual Spanish system which
showed uniformity in duration. The L2 English speakers also produced /æ/ in a region
that was more similar to Spanish /a/.
Overall, the Mexican Heritage English speakers more closely approximated the
pronunciation of the Anglo English speakers. Very subtle differences existed between
these two varieties, however, the most notable being the fronting of /i/ and /I/ in the
Mexican Heritage English relative to the Anglo variety. Both of these systems exhibited
long/short distinctions in vowel duration, but the ratio of the durational differences was
considerably less for the Mexican Heritage English speakers. In fact, the duration ratio of
long to short vowels in Mexican Heritage English was found to be less than that of Anglo
English, but greater than that observed for the L2 speakers.35 Another notable difference
between the Anglo and Mexican Heritage English variety was the difference in vowel
inherent spectral change (VISC), or formant movement throughout the course of the
vowel, for /æ/. The trajectory of /æ/ in Anglo English was considerably greater than it
was in Mexican Heritage English.
35 For the Anglo speakers, the long and short vowel systems had average values of .25 seconds and .15 seconds, respectively, indicating a separation of long vowel and short vowel systems. The MHE speakers also exhibited separation, in that their average long vowel duration was .23 seconds and the short vowel system was .18 seconds. The L2 English speakers showed less evidence of distinct long and short vowel subsystems, in that their long vowels had an average duration of .20 seconds and the short vowels and average of .18 seconds.
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A second component of this investigation consisted of accent ratings. Thirty one
naïve speakers of American English provided accent ratings of the Mexican Heritage
English speakers’ pronunciation. An analysis of the static and dynamic properties that
contributed to a speaker’s nativeness revealed that the dynamic properties, and not the
static properties, contributed more to a speaker being rated as having little foreign accent
in English.36 They found that in terms of static properties, the less fronted productions of
/i/ and /I/ were perceived as exhibiting more foreign accent—which seems
counterintuitive given that the MHE speakers produced these vowels further front than
the Anglo speakers. In terms of the dynamic properties, most notable were the voice
duration ratio (i.e., the presence of vowel lengthening preceding voiced consonants), the
VISC of the vowel /æ/, and finally the duration ratio (i.e., the degree of distinction made
between short and long vowels). Higher ratios and greater trajectories contributed to a
speaker exhibiting less foreign accent in English. Therefore, the overall results of this
study indicate that although Mexican Heritage English speakers and Anglo English
speakers may exhibit very similar vowel distribution in static terms, the distinctions
between these groups may lie in the dynamics of their pronunciation. For this reason,
they concluded that it was important to analyze both the static and dynamic properties in
order to more accurately characterize the pronunciation of a certain group of speakers.
Although the review of Chicano and Mexican Heritage English varieties
presented in this chapter is not exhaustive, the five studies reviewed above indicate
several important characteristics of the English of different Latino populations in the
36 The static properties measured were the F1 and F2 values of the English vowels measured at the 50% point throughout the vowel. The dynamic properties included the long/short duration ratio, the +voice/-voice duration ratio, the VISC.
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United States.37 Some of these studies revealed accommodation to, or adoption of certain
characteristics present in, the majority English variety spoken in the region, whereas
others did not. Godiñez and Maddieson (1985) reported the absence of /u/-fronting in the
Latino males they examined in Los Angeles, whereas Fought (1999) found evidence of
/u/-fronting within the same city. In Fought’s study, however, the presence and degree of
/u/-fronting was influenced by several social factors (i.e., gender, social class, gang-
affiliation) such that only certain participants integrated this characteristic into their
speech. In the American Midwest, Roeder (2010) reported that the female Mexican
Americans exhibited most of the characteristics of the NCVS and thus had
accommodated to the majority, non-ethnic English variety in the area. She did report,
however, that the men were at earlier stages in the NCSV, and that all speakers differed
from their Anglo-counterparts in terms of the backness of /æ/ in prenasal position. In
contrast, the two studies conducted by Konopka and Pierrehumbert (2008; in press)
reported that Mexican Heritage English speakers in Chicago had not completely
assimilated to the non-ethnic norm of pronunciation. Their productions of /æ/ were not
fronted in a way that is typically associated with the NCVS, and the formant trajectory
within this vowel was found to be less than the Anglo speakers.
Taken together, these findings indicate that although Mexican American English
varieties spoken in the United States are more closely related to the non-ethnic English
majority norms than to learner varieties and Monolingual Spanish varieties, they are still
distinct from the majority variety in specific ways. Pronunciation of specific vowels, for
example the position of /i/ and /u/, the lowering or raising of the lax high vowels /I/ and
37 See also Thomas (2001) for Tejano English and Amastae (1978) for the acquisition of English vowels by Spanish-English bilinguals and L2 learners.
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/ʊ/, and the pronunciation of /æ/ have emerged as distinct from the matrix variety in all of
the Latino and L2 English varieties discussed. What is perhaps more important, however,
is that each of the Mexican-influenced English dialects are distinct from each other.
Konopka and Pierrehumbert (2008: 102) argue that the distinctions between the Chicago
speakers and those reported in Roeder (2010) indicate that there is perhaps no “supra-
regional” Mexican Heritage English variety. The manner in which the non-ethnic
pronunciations are integrated into the Latino variety differ according to the region, as
well as according to the relationship that the minority community maintains with the
majority group of speakers. Thus, the creation of a unique system of pronunciation is
complex, and depends on a number of regional, social, and individualcharacteristics. The
next section of this chapter focuses on a review of the extralinguistic and linguistic
factors that may also influence heritage Spanish vowel pronunciation.
2.4 Individual speaker characteristics and speech production
Thus far, this chapter has provided an overview of the HS population as well as a
comprehensive description of investigations pertaining to vowel production and the
Spanish vowel system. Although the primary goal of the present study is to examine how
lexical stress, syllable type, and speech style influence the pronunciation of HS vowels, a
secondary focus is to assess the relationship between individual variables and vowel
production.
In contrast to the technical studies of vowels described in previous sections, the
secondary component of this research is sociolinguistic in nature, and could be more
specifically classified as sociophonetics. As described by Thomas (2011), studies in the
area of sociophonetics have become more prevalent within the past several decades, but
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the exact definition, components, and goals of a sociophonetic investigation depend on
the linguistic subfield in which it is carried out. For phoneticians, sociophonetics
includes studies of dialectal variation or examinations of the timing of articulatory
gestures (Thomas, 2011). The field of sociolinguistics, however, has adopted a more
specific definition. According to Thomas (2011) from the sociolinguistic perspective,
sociophonetics includes studies within the variationist framework that employ modern
acoustic techniques and experimental methods. The present investigation more closely
matches the sociolinguistic definition of sociophonetics; it employs acoustic analytic
techniques to accurately describe the pronunciation of a specific population of Spanish
speakers, while at the same time establishing a connection between the actual vowel
pronunciations and a number of sociocultural and individual characteristics.
A considerable amount of research has established that variables such as age of
learning and age of arrival to a country affect a bilingual speaker’s pronunciation and
perceived accent in the L2 or non-dominant language (Flege et al., 1995; Munro et al.,
1996). Sociolinguistic studies of vowel and consonant production have also correlated
pronunciation with traditional sociolinguistic factors such as socioeconomic class, age,
and gender (Sadowsky, 2011; Serrano, 2006; Perisinotto, 1975, amongst others).38 In
addition to these traditional sociolinguistic variables, however, a number of other factors
have been shown to correlate with HS performance on grammatical tasks and
pronunciation of certain segments. The present investigation will thus focus more
specifically on sociocultural and individual characteristics such as overt grammatical
38 As all of the HS who participated in this study were either born in the United States or moved to the country before age 6, age of learning Spanish and age of arrival to the U.S. will not be examined since all speakers are similar in these respects. The age range of these speakers is similar, thus it will not be possible to assess generational effects on vowel pronunciation. Information pertaining to each speaker’s socioeconomic class was not collected via the language background questionnaires.
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knowledge, course level, use of Spanish in the home and community, frequency of travel
abroad, and cultural sensitivity. The known relationships between each of these factors
and HS and bilingual speech production will be described in greater detail below.
Several of the investigations conducted by Montrul (2005) and Montrul et al.
(2008a; 2008b) indicated that grammar proficiency, as determined by a formal, written
exam, affected performance on different types of morphosyntactic tasks. When learners
and HS were divided into low, intermediate, and advanced groups based on their scores,
performance on morphosyntactic tasks was found to differ according to proficiency level.
The advanced level learners in particular outperformed those who had lower grammar
proficiency scores, and this distinction was revealed for both the L2 learner groups and
HS groups. As distinctions in performance on grammaticality judgment tasks based on
level of proficiency have been reported, the question then arises as to whether or not
overt grammatical knowledge will also have an effect on pronunciation. Comparisons
between L2 learners and HS often indicated that HS possessed more native-like
pronunciation, but what about within HS populations? Chang et al. (2009) reported that
at least for Chinese, experience with Mandarin and comprehension of formal and
informal situations affected the pronunciation of vowels. Although no formal grammar
proficiency test was conducted in their study, the findings suggest a correlation between
pronunciation and comprehension of the heritage language and/or the L2.39
Two other factors which have been shown to affect both morphosyntactic
knowledge and pronunciation accuracy are how often a HS speaker uses their heritage
39 As will be discussed later in chapter 5, there is some suggestion that paper-based grammar proficiency exams may not be appropriate for heritage populations given that their exposure and experience with the Spanish language has primarily been oral. For this reason, the participants will also be divided according to their course level (i.e. intermediate or advanced), as will be described in chapter 3.
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language outside of the classroom, and how frequently they travel abroad to visit with
family and friends in a Spanish-speaking country. One such study conducted by
Mikulski (2010) examined how age of arrival to the United States, use of Spanish in the
home and community, and frequency and length of travel to hispanophone countries
affected HS’s recognition and judgment of the Spanish subjunctive in volitional
constructions. The participants in this investigation were 32 heritage speakers of Spanish
who were further divided into two groups. Those who were born in the United States or
arrived before age 6 were referred to as “early childhood” bilinguals because their
exposure to English began as young children (n=24). The other 8 participants were
grouped as “late childhood bilinguals” because they had arrived to the United States
between the ages of 6-12 years. All participants completed a language background and
use questionnaire, a grammaticality judgment task, an editing task, and a cloze task to
ensure that the participants had not confused the thematic vowel in the Spanish verbal
conjugations.
Multivariate linear regressions were conducted in order to determine the
relationship between the sociocultural variables and HS performance on the grammatical
tasks. The results indicated that there were no significant differences in performance
based on age of arrival (“early” vs. “late” childhood bilinguals). Spanish use and travel
abroad, however, were found to affect performance on certain tasks. Increased use of
Spanish with family and longer stays abroad were positively correlated with the scores in
the editing task. Thus, those participants who reported speaking Spanish more frequently
at home and those who had spent at least two weeks abroad and had visited Spanish-
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speaking countries more than once outperformed those HS who used less Spanish and did
not travel.
Duprey-Almeyda (2009) examined the effects of language attitudes and travel
abroad the on vowel perception and production by L2 learners of English residing in
Puerto Rico. The participants in this study were tenth graders at a Puerto Rican high
school who were studying English as a second language. A series of production and
perception experiments were conducted which analyzed the learners’ ability to produce
and identify English monophthong vowels. Additionally, several language background
and attitudes questionnaires were administered in order to assess the extent to which
these extra-linguistic factors influenced speech production and perception. The results of
the investigation indicated that although all of the students had a positive attitude toward
English and showed a high level of cultural sensitivity, those learners who had “state-side
ties” showed a greater ability to produce native-like vowels and also had higher
perception scores. Thus, those students who maintained familial ties or relationships with
people in the United States exhibited more native-like production of English vowels and
were better able to perceive them when compared to those students who did not have the
same connections with the U.S.
The study conducted by Mikulski (2010) indicated that the frequency with which
a bilingual speaker or HS uses their heritage language outside of the classroom and how
often they travel abroad had significant effects on pronunciation and morphosyntactic
knowledge. Duprey-Almeyda’s (2009) investigation revealed that maintaining strong ties
with the heritage culture had a positive impact on language attitudes as well as speech
production and perception. Thus, in an indirect way, Duprey-Almeyda’s study found that
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the strength of the connection with the heritage culture was influential in their speech
production. The results of Mikulski and Duprey-Almeyda therefore suggest that there
may be a connection between HS vowel production, frequency of travel abroad and
Spanish use.
A final sociocultural variable addressed in this investigation is cultural sensitivity.
Alvord and Christiansen (2009) examined the effects of language attitudes, cultural
sensitivity, and motivation on the acquisition of spirantization in Spanish by adult
learners in a study-abroad context. A group of 34 male participants who were studying
abroad in various Spanish speaking countries with a service-oriented program completed
narrative and elicitation tasks containing the target sounds /b d g/ and their spirantized
allophones. In addition to the linguistic tasks, the participants completed a cultural
sensitivity questionnaire developed by Cushner (1986), which was designed to assess
each participant’s general degree of cultural awareness and sensitivity. The statistical
analysis indicated that motivation and overall cultural integration were two of the factors
selected as significantly affecting acquisition of the target sounds. That is, those
participants who scored higher on the cultural sensitivity questionnaire and exhibited
higher motivation scores produced target sounds that more closely approximated native
speaker norms.
The present investigation examines each speaker’s level of cultural sensitivity by
utilizing the same questionnaire employed by Alvord and Christiansen (2009).40 As will
40 Although Alvord and Christiansen (2009) reported that motivation and attitudes towards language were also significant predictors of pronunciation accuracy, this dissertation will not directly examine these additional variables. Despite including open-ended and multiple choice questions that were meant to assess each speaker’s attitudes toward the language and motivation to speak it, all participants responded similarly. Because of the homogeneity in the responses, it was not possible to include these variables in the analysis.
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be explained further in chapter three, this questionnaire is further divided into subscales
which can subsequently be correlated with pronunciation accuracy and performance.
Given the limited number of participants in this study, only the total sensitivity score will
be examined.
In summary, the literature presented in this section indicates that HS
pronunciation could potentially be influenced by a number of extra-linguistic factors.
Grammar proficiency and course level have been shown to correlate with
morphosyntactic knowledge, but thus far it is unclear if HS with more advanced
grammatical skills and those enrolled in upper-level courses will exhibit differences in
their pronunciation when compared to those with less overt grammatical knowledge and
formal instruction. The use of Spanish outside of the classroom and frequency of travel
abroad have been shown to significantly affect the pronunciation of vowels and
performance on morphosyntactic tasks. Thus, there may be a correlation between these
two variables and HS vowel pronunciation, even within this small sample size. Finally,
additional research has established a connection between a speaker’s cultural sensitivity
and their pronunciation. As cultural sensitivity increased, so did the pronunciation
accuracy of specific L2 segments. Further detail pertaining to the instruments and
scoring rubrics will be provided in the following chapter.
2.5 Research questions and hypotheses
The literature described in the previous sections of this chapter motivates the need
for further investigation of HS pronunciation as well as a more in-depth investigation of
Spanish vowels. Heritage speakers are a population of interest given that, despite the
large number of investigations focusing on morphosyntax and pedagogy, fewer studies
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have focused on HS pronunciation. Vowel systems are also of interest in this
investigation. There are few acoustic studies of Spanish vowels to date, and of those
existing studies, there is a considerable amount of disagreement among researchers as to
which linguistic factors influence vowel pronunciation in Spanish—especially when
bilingual varieties of Spanish are taken into consideration. In addition, most of the
investigations focus on highly controlled and unnatural speech styles such as carrier
phrases, thus, little is known about how, and in what way, the vowel system of Spanish
can vary as a consequence of style. Previous studies of bilingual Spanish and bilingual
English vowel systems show that speakers of contact varieties possess a modified system
of pronunciation that differs from the monolingual norm and/or matrix variety within the
same region. Systems of contact pronunciation, however, are complex, and are
influenced by a number of extra-linguistic factors. These general findings, then, have
guided the development of research questions and hypotheses for the present study:
Q1: How are HS vowels organized and dispersed throughout the system, and how
does this organization and dispersion compare to traditional and acoustic
descriptions of monolingual Spanish varieties?
H1: If heritage speakers do exhibit native-like pronunciation, their vowel
productions will approximate the descriptions of monolingual Spanish vowel
systems presented in the literature.
H2: Heritage speaker vowel pronunciation will conform to sociocultural norms
associated with the population, such as the backed position of /e/ in Mexican
American Spanish described by Lipski (2008).
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H3: The heritage Spanish vowel system will be a hybrid, exhibiting
characteristics associated with English such as the fronted position of /u/.
Q2. How do lexical stress, syllable type, and speech style affect HS vowel quality,
quantity, and dispersion?
Q2A: How does lexical stress affect HS vowel quality, quantity, and dispersion? Do
tonic and atonic vowels exhibit little quality and quantity differences as argued for
monolingual varieties of Spanish, or do they exhibit stress differences more in line
with what is argued for bilingual and learner varieties?
H1: Lexical stress will have little impact on vowel quality, dispersion, and
duration, as is traditionally claimed in descriptive accounts of monolingual
Spanish varieties (Delattre, 1969).
H2: Heritage speakers will exhibit the unstressed vowel reduction that is
characteristic of central Mexican varieties of Spanish. The front vowels /e/ and /i/
will be the most affected, with atonic /i/ and /e/ exhibiting shorter duration and a
position farther back in the vowel space when compared to their tonic
counterparts (Matluck, 1952; Lope Blanch, 1972).
H3: Heritage Spanish vowels will exhibit contact-induced differences in quality,
dispersion, and quantity similar to those described for other bilingual and L2
learner systems. In particular, atonic vowels will show movement towards the
center of the vowel space along the F2 dimension, will occupy less peripheral
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locations in the acoustic space when compared to their tonic counterparts, and
will be shorter in duration than tonic vowels (Menke & Face, 2010; Willis, 2005).
Q2B: How does syllable structure (closed versus open syllables) affect vowel
quality, dispersion, and quantity? Is there variation based on syllable type, or do
HS fail show allophonic differences, as has been argued in the majority of the
acoustic literature?
H1: Heritage Spanish vowels will exhibit the allophonic variation based on
syllable type that is described for monolingual Spanish varieties (Navarro-Tomás,
1918). The mid vowels /e/ and /o/ will be characterized by more open
articulations in closed syllables, and close articulations in open syllables.
H2: Syllable type will not impact HS vowel quality, but will have an effect on
vowel duration (Marín Gálvez, 1995).
H3: Syllable structure will not impact the production of HS Spanish vowels,
indicating that the distinction is not present in this variety.
Q2C. How does speech style (spontaneous vs. controlled) affect HS vowel quality,
quantity, and dispersion? Do HS exhibit the same quality and quantity differences
based on speech style that have been found for monolingual and bilingual varieties?
H1: The HS in this study will not exhibit differences in vowel quality, dispersion,
or duration based on speech style. The absence of a style effect may suggest that
HS have not acquired the fine-grained distinctions in style exhibited by
monolingual speakers.
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H2: Heritage speakers of Spanish will exhibit differences in vowel quality,
dispersion, and duration much like those reported for other monolingual and
bilingual populations. More specifically, vowels produced in controlled speech
will occupy a more peripheral location within the acoustic space when compared
to those produced in the spontaneous speech tasks (Alvord & Rodgers, 2011;
Harmegnies and Poch-Olivé, 1992; Poch-Olivé et al., 2008).
Q3: Do individual variables influence the way in which HS pronounce their vowels?
H1: There will be no relationship between individual variables (i.e., course level,
grammar proficiency, travel, Spanish use, and cultural sensitivity) and HS vowel
production.
H2: The same factors known to impact HS morphosyntactic knowledge (i.e.,
grammar proficiency, Spanish use, travel abroad) will impact HS pronunciation of
the Spanish vowels (Mikulski, 2010; Montrul, 2005).
H3: HS vowel production will be influenced by the same factors known to
influence L2 pronunciation accuracy and the acquisition of L2 phonology.
Course level, travel abroad, regular use of the L2, and high degrees of cultural
sensitivity have been positively correlated with the acquisition of L2 segments
(Alvord & Christiansen, 2009; Chang et al., 2009; Díaz-Campos, 2004; Menke &
Face, 2010).
In order to assess the research questions addressed above, a series of acoustic
experiments were designed and carried out with a group of HS from the Chicago area.
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The next chapter provides detailed explanations of the participants, tasks, data analysis,
and statistical methods that were used to analyze the acoustic data.
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3 METHODOLOGY
The purpose of this chapter is to describe the speech elicitation tasks and
questionnaires, the participants, the data collection and analysis, and the statistical
analyses that were conducted in the present investigation.41 Each of these
methodological components is described in greater detail below.42
3.1 Instruments
The participants took part in three oral speech tasks in order to elicit the
production of Spanish vowels in different contexts as well as in different speech styles.
A language background questionnaire and a cultural sensitivity questionnaire were
administered, along with a grammar proficiency test. The speech elicitation instruments
are discussed in sections 3.1.1 through 3.1.3. The other instruments are described in
sections 3.1.4 through 3.1.6.
3.1.1 Narrative retelling task
The first speech elicitation instrument consisted of a narrative retelling task
(hereafter NRT) that was included as a means to gather spontaneous speech. The
participants were asked to view the video “The Tortilla Rag” (Malovrh, 2008) and then
asked to orally narrate the series of events upon completion of the film. “The Tortilla
Rag” is a short, silent video that depicts two people preparing a tortilla española – a
41 Prior to collecting the official dissertation data, the instruments were piloted several times to ensure they would prompt the intended lexical items and to ensure that enough vowel tokens would be produced by the tortilla rag. Three separate pilot investigations were collected. Two were conducted in Bloomington, Indiana in August of 2010 and in September of 2010. Two participants took part in each pilot. The third pilot was conducted in Chicago, Illinois, during October of 2010. Four participants completed this version of the experiment. All lexical items that could not be consistently elicited in the picture memory task were either eliminated or were moved to the carrier phrase task. 42 The pilot version of this experiment as well as the final dissertation instruments are approved by the Indiana University Institutional Review Board Protocol # 0911000827.
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traditional Spanish dish that resembles an omelet, consisting of eggs, potatoes, and
onions. Although it was originally designed to elicit direct and indirect object pronouns
(Malovrh, 2008), there are numerous actions and objects that prompt the production of
Spanish vowels in a variety of contexts. The author of the video gave his permission to
include it as one of the instruments in this dissertation.43 Images from the video are
shown in Figure 3-1.
Figure 3-1. Images from the Tortilla Rag, narrative retelling task.
The data collected from the narrative provided semi-spontaneous, unplanned
speech that more closely resembled natural speech when compared to the other tasks
utilized in this dissertation. Using a video such as this also provided some consistency in
terms of the number and types of lexical items obtained from each participant. Although
this video did not elicit an equal number of tokens of each vowel in all of the prosodic
and syllabic contexts, it did provide a sufficient amount of vowels to examine the basic
distribution within the acoustic space. The duration of the narrative retellings varied in
length according to the amount of detail the participant included. On average, the
43 The video (in two parts) can be accessed via Dr. Paul Malovrh’s personal website: http://www.cas.sc.edu /dllc/ Spanish/faculty/Malovrh/malovrh.html
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recordings lasted approximately 90 seconds, although one recording was as short as 45
seconds and another reached 4 minutes and 25 seconds. The average number of vowels
produced in this task was 70. One participant only produced 38 analyzable vowels,
whereas another produced 114.
3.1.2 Picture identification task
Upon completion of the NRT, the participants were asked to complete a picture
identification task (hereafter PIT). The goal of the PIT was to obtain semi-spontaneous
speech by asking participants to identify and name images of objects, animals, and food
presented on a computer screen. Unlike the NRT which consisted of spontaneous speech,
the PIT was semi-balanced by the syllabic and prosodic contexts under investigation (i.e.,
tonic vs. atonic; closed vs. open syllables). The images utilized in the PIT were carefully
selected to elicit the five Spanish vowels in different prosodic and syllabic contexts,
resulting in the production of 80 total vowels. Although most of the images used in the
PIT represented common, everyday objects, some less common words were included in
order to provide examples of all vowels in all contexts. A list of the words included in
the PIT is presented in Appendix A. In total, the PIT lasted approximately 10 minutes,
and consisted of 123 power point slides that included the contextualization of the task,
the instructions and models, the familiarization phase, and the final task phase. Further
information about the PIT and sample slides are presented in the following paragraphs.
The PIT was presented to the participants as if it were a memory game, and they
were given a scenario to help contextualize the lexical items they would be asked to say.
It consisted of two phases: a training phase and an actual task phase. Before the actual
task began, participants were familiarized with the names of the objects they were going
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to see.44 For example, they were presented with an image like the one shown in Figure
3-2, and were asked to say out loud the number and the name of the object they saw. The
first few letters of the object name were provided to help eliminate any ambiguity as to
what the object was. Figure 3-2 is a model slide consisting of a picture of three bananas
that was meant to prompt the phrase tres plátanos (“three bananas”).
Figure 3-2. Sample training slide from PIT.
Once the participants had been familiarized with the objects, they proceeded to
the actual task. They were told that they were helping their friend Marta plan a surprise
party for their mutual friend Pablo. Marta had invited a number of guests to the party,
and had asked that they each bring a gift or a of food item to share at the party. She had
asked you (the participant) to keep a record of who had already arrived and what they
brought as a gift. The participants were shown a model like the one presented in Figure
3-3 so they understood that they needed to say the name of the person who brought the
item, as well as what, and how many, they brought. Figure 3-3 presents two model slides
44 The decision to include a familiarization phase was motivated by difficulties in the pilot experiments. In the pilot trials of the picture identification instrument, some participants did not say the word intended, resulting in the inability to analyze the vowel that was needed. In order to ensure that the participants would say the intended lexical item, they were first familiarized with each item. If they were not able to identify the item, the investigator wrote down the name of the object for them.
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from the PIT. The first slide is a sample, and prompts the response María trajo dos
galletas (“María brought two cookies”). The first slide includes the word modelo
(“model”) and ves (“you see”) to indicate that the slides are for practice. The second
slide includes the word dices (“you say”) in red in order to demonstrate how the
participant would be expected to respond upon seeing the slide. The phrase ¿Qué trajo?
(“What did he/she bring?”) was included on each slide to remind the participants that
they needed to respond to the question in a complete sentence. During the actual task
phase, the words modelo, ves, and dices were not included on the slide – only the picture
of the person and their name, the images of the objects, and the question ¿Qué trajo?
were presented.
Figure 3-3. Model slide from actual task phase in the PIT.
In addition to the normal, every-day object names presented in the PIT, a number
of uncommon objects and animal names were included in order to obtain all five Spanish
vowels in all of the stress and syllable type contexts. To integrate the less common
lexical items into the party scenario, participants were stopped halfway through the task
and given further instructions. They were told that some of the guests did not follow
instructions and brought very strange “gifts” with them. As with the previous portion of
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the PIT, the role of the participant was to report to Marta what each person brought so
that she could decide if they would be permitted to come to the party or not. Figure 3-4
depicts one of the “strange” gifts, and was intended to elicit the response Carlitos trajo
tres avispas (“Carlitos brought three wasps”).
Figure 3-4. Slide of "strange" gift from the PIT.
As mentioned previously, the images used in this task include lexical items
containing tonic and atonic vowels in both closed and open syllables. Care was taken to
avoid the creation of vowel coalescence or synalepha between the indefinite article and
vowel-initial target words by including multiple pictures of the object: either “dos,”
“tres,” or “seis.” Also, the majority of the target vowels were flanked by either stop or
fricative consonants to facilitate segmentation and avoid any potential effects or
difficulties due to the presence of liquids or nasals45.
In total, there were 64 different lexical items included in the task, with two to four
examples of each vowel in each of the contexts (i.e., tonic open /a/, tonic closed /a/,
atonic open /a/, atonic closed /a/). Only the utterances from the task phase were included 45 Given the difficulty in finding images that were recognizable and were appropriate for the party scenario, some instances of nasals and liquids were included. As will be discussed later on in this chapter, all formant measurements were taken at the midpoint of the vowel in an attempt to minimize the influence of the surrounding consonantal context.
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in the overall analysis.46 Several of the categories included more than four lexical items
containing the target vowel, as can be seen in Appendix A. For the atonic vowels, only
those in pretonic position were analyzed. The decision to exclude final vowels was made
based on previous findings that final vowels in some dialects of Spanish can be devoiced,
reduced, or in contrast, even lengthened (Delforge, 2008; Hualde, 2005; Lipski, 1994;
Lope Blanch, 1972; Matluck, 1952).
3.1.3 Carrier phrase task
After completing the PIT, participants completed a traditional carrier phrase task
(hereafter CPT) intended to gather controlled speech. The participants were asked to
produce a series of Spanish words within the carrier phrase La contraseña es_____ (“The
password is_____”). Fifty six total words were included in this task, yielding 66
potentially analyzable vowels.47 All of the words included in the carrier phrase task are
presented in Appendix B. All words were presented on a computer screen via power
point over the course of 64 slides that included the contextualization of the task, model
slides, and the target words. Most participants completed the CPT in five minutes.
As with the picture description task, the elicitation task was couched within a
game-like scenario in which the participants were told that they needed to remember a
certain password to enter a science lab. The word list consisted of real Spanish words
(i.e., no non-words) containing the five Spanish vowels between all combination of
46 Initially the intention was to include elicitations from both the training and the task phase in the PIT. Many of the participants did not know the name of the object and had to be helped, stuttered, or did not agree with what the object was called. Due to these complications, only the second repetition in the actual task phase was analyzed. 47 As some of the words included in the CPT were bi-syllabic, both the atonic and tonic vowels were extracted when possible.
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/ptks/.48 The near-minimal series beginning with /m/ (i.e., masa, mesa, misa, etc.) was
also included in this task. Finally, in addition to the bi-syllabic words mentioned above,
several tri-syllabic words were included in the CPT. The additional words include
examples of tonic and atonic vowels in closed and open syllables, and were items that
were too difficult to include in the PIT because they were either too uncommon or were
not successfully elicited in the pilot experiments. Sample slides from the CPT are
presented in Figure 3-5. These two slides were included as practice, and for this reason
they include the words modelo (“model”), ves (“you see”), and dices (“you say”).
MODELOVES:
La contraseña es….
perro
MODELODICES:
“La contraseña es perro.”
Figure 3-5. Sample slides from CPT.
The CPT was included in the present investigation for two main reasons. First of
all, a carrier phrase including vowels in neutral or similar consonantal contexts is a
frequently-employed methodology in vowel research (see Bradlow, 1995; Morrison &
Escudero, 2007; Servín & Rodríguez, 2001). Including a CPT in the present study
facilitates comparisons across studies between HS vowel productions and vowels
produced by monolingual speakers of Spanish. Second of all, the CPT represents what
has been referred to as “laboratory” speech, and represents a very controlled speech style. 48 Not all combinations of /ptks/ and the five vowels produced actual Spanish words. For example, combinations such as /kuso/, /pupo/, and /tuto/ were not included. The consonants /p,t,k/ were also chosen so that future investigations could examine HS VOT.
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As discussed in chapter 2, section 2.2.3.3, previous research suggests that vowels are
produced differently in terms of quality based on the type of speech in which they are
produced (Harmegenies & Poch-Olivé, 1992, Poch-Olivé et al, 2008). Thus, the current
investigation includes three tasks that represent three different speech styles:
spontaneous, semi-spontaneous, and controlled.
3.1.4 Language background questionnaire
All participants completed a written language background and history
questionnaire in order to gather information pertaining to their experiences and usage of
both English and Spanish in their daily lives (see Appendix C). The responses to the
written questionnaire ensured that participants originated from roughly the same region
within the United States and/or Mexico; inquired whether or not they had studied another
foreign language; how often they traveled abroad; and how often and how frequently they
spoke, listened to, or wrote English and Spanish in different contexts. Participants’
responses pertaining to frequency of travel abroad and Spanish use were included in the
statistical model and correlated with HS vowel production. The procedure for obtaining
travel frequency and Spanish use are described in greater detail in sections 3.4.2.3 and
3.4.2.4, respectively.
3.1.5 Grammar proficiency test
All participants completed a short grammar proficiency exam consisting of 25
multiple choice questions (Geeslin & Gudmestad, 2010). The purpose of the grammar
proficiency activity was to ensure that the participants had comparable proficiency in
Spanish. The scores on this exam were then correlated with the experimental results in
order to examine the effects of Spanish grammar proficiency on vowel production. The
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grammar test is presented in Appendix D. Further information pertaining to the grammar
proficiency activity and how it was included in the statistical model is discussed in
section 3.4.2.2.
3.1.6 Cultural sensitivity questionnaire
Finally, each participant completed Cushner’s (1986) Inventory of Cross-Cultural
Sensitivity (ICCS) (see Appendix E). The ICCS questionnaire contains a series of
statements in English. Each participant was asked to indicate how strongly they agreed
or disagreed with each statement. The scale ranged from 1-7, with 1 indicating a
response of “strongly disagree” and 7 a response of “strongly agree.” The responses
were then organized into several different subscales: Cultural Integration, Behavioral,
Intellectual, Attitude, and Empathy. The sum of the scores tabulated for each of the
subscales produced the overall cultural sensitivity score. The range of possible scores on
the ICCS is between 32 and 224 points. Higher scores indicate greater degrees of cultural
sensitivity, whereas lower scores indicate lesser degrees of cultural sensitivity.
Additional information pertaining to the ICCS and how it was correlated with HS vowel
production is described in section 3.4.2.5.
3.2 Participants
Sixteen heritage speakers of Spanish (13 females and 3 males) participated in this
study. A full table of demographic information is presented in Appendix F. All
participants were current residents of Chicago, IL, and were students at the University of
Illinois, Chicago. The mean age of the participants was 20.1 years. Thirteen participants
were born in the United States and had lived in Chicago their entire lives. Three
participants were born in Mexico and moved to the United States at the ages of 2, 6, and
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8 years of age. Fifteen of the participants were of Mexican heritage, and one was of
Puerto Rican heritage. Fourteen of the participants were born to parents of the same
heritage (i.e., either both Mexican or both Puerto Rican). Two participants were of mixed
heritage: one was born to a Mexican mother and a Castilian Father, and the other was
born to an American mother and a Mexican father.
The educational background of the participants who completed this study was fairly
consistent. Twelve participants began formal study of Spanish in high school at age 14 or
in college at ages 17-18. Two participants indicated that they received formal Spanish
instruction in elementary school, and one participant was enrolled in a bilingual
education program for one year. One participant did not indicate the age at which she
began studying Spanish.
All participants indicated that they lived in predominantly Hispanic communities
within the Chicago area and spoke Spanish at home and within the community on a
regular basis.49 Additional information pertaining to Spanish use was gathered from the
language background questionnaire, and will be explained in greater detail in section
3.4.2.4. All participants reported that they overheard and spoke Spanish starting from a
very early age, and most reported that their exposure to Spanish began at birth. Eleven
participants indicated that their native language was Spanish, one participant indicated
that her native languages were both Spanish and English, and the remaining four
participants indicated that they considered their native language to be English.
49 Although not all participants indicated the neighborhood in which they lived, more than half reported that they lived near the University of Illinois, Chicago. Some specifically mentioned residing in Mexican-American communities such as Pilsen and Little Village, which are located to the south and the southwest of the University, respectively.
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At the time the study was conducted, seven of the 16 participants were enrolled in
S114 (Spanish for Bilinguals II). Spanish for Bilinguals II is an intermediate-level
grammar course designed specifically for HS of Spanish. The goals of the course are to
re-introduce HS to key grammatical concepts and help develop additional reading,
speaking, and writing skills. The other nine participants had already completed S114 and
were enrolled in 200 and/or 300 level courses such as S202 (Advanced Spanish
Grammar), S204 (Intensive Writing), S210 (Literature), or S380 (Independent Study).
More detailed demographic information pertaining to linguistic and developmental
history, language use, and ethnic self-identification is presented in Appendix F.
3.3 Procedure
This section of the chapter describes the order in which the tasks were completed
and the devices that were used for stimulus presentation and recording. After completing
the informed consent documents, each participant was first asked to view the video
“Tortilla Rag” and subsequently asked to retell as much of the information as they could
remember. Next, each participant completed the PIT, followed by the CPT. Once the
three recorded tasks were finished, all participants completed the written grammar
proficiency test, the language background questionnaire, and the cultural sensitivity
questionnaire.50 Participants took part in the experiment one at a time, with only the
experimenter present to help guide them through the tasks if they had any questions.
50 In addition to the tasks for eliciting Spanish vowels described in section 3.1, the participants were also asked to provide examples of their English vowels by completing a carrier phrase task and paragraph reading in English. The phrase for the carrier was “I say ___ for you.” The paragraph reading involved a fictional story about a summer vacation in which words containing all of the cardinal vowels were embedded. The production of English vowels is not discussed in the present dissertation.
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Upon completion of all of the materials, each participant was paid $10 for taking part in
the experiment.
All of the stimuli were presented on a Hewlett-Packard G62 laptop computer with
a 15.6 inch screen. The “Tortilla Rag” was presented via Windows Media Player, and the
PIT and CPT were presented with Microsoft Power Point 2010. Each participant’s
speech was recorded using a SHURE head-mounted microphone and a USBPre interface
that was run through a Dell Inspiron mini netbook.51 The participants’ speech was
subsequently analyzed using Praat Software (Boersma & Weenink, 2010). All of the
recordings took place in a quiet room or classroom on or near the UIC campus. The
series of experiments and questionnaires took approximately one hour to complete.
3.4 Data analysis
The purpose of this section of the chapter is to describe how the data were
segmented and analyzed and explain the statistical tests that were conducted on the
variables examined in this dissertation. Section 3.4.1 describes the procedure for
segmenting vowels, the criteria for excluding vowel tokens, extracting vowel formants,
calculating vowel duration, calculating the centroid and Euclidean distance measures, and
normalization. Section 3.4.2 explains the individual variables in greater detail, and
describes how the questionnaires were scored. Finally, section 3.4.3 describes the
statistical analyses employed in the present study.
51 For more information about the USBPre, see the following website: http://www.sounddevices.com /products/usbpremaster.htm
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3.4.1 Acoustic measures
The audio recordings obtained from each participant were analyzed in Praat
Software v. 5.1.44 (Boersma & Weenink, 2010). Vowels were first segmented out of the
running speech samples, as described in section 3.4.1.1. The first and second formant
frequencies and vowel duration measures were calculated using procedures described in
sections 3.4.1.3 and 3.4.1.4, respectively. The first and second formant frequencies were
used to determine the center of each speaker’s vowel space, and the Euclidean distance
measure of each vowel to the center was subsequently calculated (section 3.4.1.5). The
first and second formant frequencies, duration, and Euclidean distance are the four
dependent variables in the statistical analysis. Further information about statistics is
presented in section 3.4.3.
3.4.1.1 Segmentation of vowels
All vowels were segmented out of the larger speech samples obtained in the three
elicitation tasks. The formant transitions into and out of vowels and the degree and
direction of formant trajectories are extremely sensitive to the surrounding consonantal
context (Rosner & Pickering, 1994; Stevens & House, 1963). Given this contextual
sensitivity, a series of cues found in the waveform and the spectrogram were utilized in
order to determine the onset and offset of each vowel.
In order to identify the onset of a vowel following a stop consonant, several main
acoustic cues were identified in the acoustic signal. First, the release burst from the stop
consonant was located, which signals the release of the stop consonant and the onset of
the following vowel. A second important cue was the increase in intensity in the
waveform and the spectrogram. As a stop consonant is characterized by the lack of
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activity in the waveform and the spectrogram, the sudden increase in energy in the
acoustic signal signified the onset of the vowel. Periodicity, or cyclic repetition, in the
waveform was the third cue that facilitated segmentation of the vowel. Finally, the
onset of clear and regular formant structure was also used as a means to determine the
starting point for each vowel. In order to determine the offset of a vowel when it
preceded a stop consonant, the reverse of these cues was used. Thus, the end point of the
vowel was identified based on a sudden loss of intensity and energy in the waveform and
the spectrogram, a sudden lack of periodicity, and a shifting and breaking up of the
regular formant structure characteristic of a vowel.
Figure 3-6 illustrates the segmentation of the vowel [a] in the word tapa (“lid,”
“top”). The top panel is a representation of the waveform in which the boundaries of the
first “a” are delineated by the dashed lines. The second panel includes the spectrogram in
which the same vowel is segmented. Below the acoustic panels, a text grid is included
which serves to label the vowel sound and the entire word. The silent portion before the
segmented vowel is the closure for the stop consonant. The small burst represents the
release of the stop consonant, followed by the voiced onset time. After the VOT, there is
a large increase in intensity in the waveform as well as periodicity and clear formant
structure in the spectrogram. Once the vowel has ended, another period of silence, seen
in both the waveform and the spectrogram, corresponds to the following stop consonant
[p].
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Figure 3-6. Waveform and spectrogram of the word tapa (“lid”) with acoustic cues for segmentation and measurement.
In order to identify vowels that were surrounded by fricative consonants, a
slightly different set of cues needed to be used given the nature of fricatives. As
fricatives allow for the partial passage of air through the oral cavity, they exhibit a degree
of aperiodic noise in the waveform as well as high frequency noise in the spectrogram.
Vowels in the context of fricatives were thus identified based on the increase in intensity
in the waveform as well as a shift from aperiodic noise to a periodic waveform. In the
spectrogram, the vowel was identified by the onset of clear formant structure. The offset
of a vowel in contact with a fricative was determined by the shift from periodic waves to
aperiodic noise, a decrease in intensity in the waveform, and the breaking up and shifting
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of formant in the spectrogram. Figure 3-7 exemplifies the segmentation of the vowel [i]
in the word sistema (“system”), which is flanked by two sibilants. Prior to the vowel, one
can see the aperiodicity of the sound wave in the waveform, as well as high frequency
noise and lack of clear formant structure in the spectrogram. This corresponds to the first
[s] in sistema. The wave then becomes periodic and has a higher amplitude, signifying
the vowel. Steady formants also appear in the spectrogram, corresponding to the vowel
[i]. The wave amplitude decreases as the offset of the vowel approaches, and the wave
becomes less sinusoidal. The formants that were once clear in the vowel begin to
disperse and are replaced once again by high frequency noise that represents the second
[s] in sistema.
Figure 3-7. Waveform and spectrogram for the word sistema (“system”).
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The segmentation of vowels in contact with resonant consonants can be less
straight-forward than in the previous examples. The difficulty in finding clear boundaries
for a vowel in contact with sonorant consonants is due in part to the fact that they share
many spectral characteristics with vowels. Sonorants, too, exhibit a high degree of
energy and periodicity in the waveform and have clear formant structure that is visible in
the spectrogram. The main cues for identifying vowels in contact with nasals and liquids
is the increase in intensity in the waveform relative to the neighboring consonants and a
shifting in formant structure as indicated by the formant tracker.52 Nasal consonants, for
example, are characterized by the coupling of the first and second formants, resulting in a
large concentration of energy in the low frequency ranges. When a nasal consonant is in
contact with a front vowel that has a high second formant such as [e], the second formant
must shift and rise as it transitions from the nasal into the following vowel. This
movement is one of the main cues that helps identify the onset of a vowel in this
consonantal environment. Figure 3-8 is a representation of the waveform and
spectrogram of the word mano (“hand”). The vowel [a] has been segmented out of this
word as indicated by the vertical lines and the label on the first tier of the text grid.
Notice that there is a decrease in wave amplitude in the nasal sounds, as well as a
concentration of energy in the low frequency ranges for the nasal that is not present in the
vowel.
52 The formant tracker is a component of Praat Software that identifies the center frequencies of the formants, thus indicating the frequency of the concentration of energy for a given speech sound.
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Figure 3-8. Waveform and spectrogram for the word mano (“hand”).
The shifting and transitioning of formants and the relative increase in intensity in
the waveform are also the primary cues for identifying a vowel when it is in contact with
a lateral consonant. As there is a partial closure formed by the tongue and the alveolar
ridge when forming an [l] in Spanish, there is some decreased intensity in the waveform
even though the formant structure may be maintained in the spectrogram. As laterals
typically involve a closure, there is also an apparent break in the formant structure (a
discontinuity) indicating the transition between sounds (Ladefoged, 2003, p. 146). Figure
3-9 shows the segmentation of the vowel [a] in the word lapiz (“pencil”). Note the
shifting of formants and increase in wave amplitude as the vowel is produced.
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Figure 3-9. Waveform and spectrogram of the word un lápiz (“a pencil”).
Finally, the segmentation of a vowel when in contact with a rhotic (trill or flap) is,
in some ways, similar to when a vowel is in contact with a stop consonant. As Spanish
rhotics are typically characterized by one or more closures in the oral cavity caused by
contact between the tongue and the alveolar ridge, a brief silence (white portion) is often
visible in the spectrogram. Although the closure may be too brief to obscure the formant
structure as indicated by the formant tracker in Praat, the silence in the spectrogram is
also accompanied by a rapid and brief decrease in intensity in the waveform. Figure 3-10
represents the waveform and spectrogram for the word cucharas (“spoons”). The first
repetition of [a] has been segmented out of the word as indicated by the vertical lines and
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label on the first tier of the text grid. The brief silence following the vowel represents the
closure of the rhotic.53
Figure 3-10. Waveform and spectrogram of the word cucharas (“spoons”).
To summarize this section briefly, the onset and offset of the vocalic segments
analyzed in the present investigation were determined by taking into consideration a
combination of the acoustic cues mentioned above. The surrounding segmental context
determined which characteristics were the strongest cues signaling the onset and offset of
the vowel under investigation. The presence of at least two cues was preferred in order to
identify a vowel. If at least two cues were not identifiable, the vowel under investigation
53 The second /a/ in the figure is produced with creaky voice. As will be discussed later in this chapter, vowels produced with creak were not included in the present study.
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was marked as questionable and was checked by another trained phonetician. If the
researchers were unable to reach agreement on the boundary of the vowel given the
presence of only one acoustic cue or two weak acoustic cues, the vowel was excluded
from the analysis.54 Care was taken in the design of the stimulus materials to include
lexical items with vowels in contexts that were conducive to segmentation (e.g., between
two stop consonants or between a stop and a fricative). In the narrative retelling task,
however, the lexical items produced by each participant were not always consistent. In
order to include vowels in all of the syllable and stress type contexts under investigation,
it was sometimes necessary to include vowels produced in less clear-cut segmentation
contexts.
3.4.1.2 Exclusion of vowels
The primary goal of this study is to provide a descriptive characterization of the
Spanish vowel system of HS of Spanish. For this reason, only monophthong (“pure”)
vowels were included in the present analysis. Only the vowels in the target words in the
PIT and CPT were included. In the NRT, all analyzable vowels that occurred in lexical
words (i.e., nouns, verbs, adjectives, and adverbs) were included in the analysis. Vowels
that were in absolute word-final position were excluded from the analysis because, as
mentioned earlier, final vowels in certain dialects are subject to lengthening, devoicing,
or reduction (Delforge, 2008; Hualde, 2005; Lipski, 1994; Lope Blanch, 1972; Matluck,
1952). Phonemic diphthongs were excluded, as well as mid vowels that had been
diphthongized. Diphthongs consist of a combination of two vowels within the same
54 In total, 104 vowels were excluded from the analysis because they were either produced with creak, devoiced, in contexts where segmentation was unclear, because the participant produced an unintended lexical item, or because the participant produced the intended lexical item in English.
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syllable: a high vowel [i] or [u] that is weakened to a semivowel, and an additional
vowel (Hualde, 2005). Diphthongs differ from simple vowels in that they tend to be
longer in duration and are characterized by considerable spectral movement from one
vowel to another. Thus, the inclusion of diphthongs in this analysis would not provide an
accurate description of the Spanish five-vowel system, but rather show how vocalic
segments interact and combine with one another.
Vowels that occurred in the context of the approximant [j] were also excluded,
given the difficulty in locating the boundary between voiced approximants and vowels.
The location of the boundary between these sounds is problematic because they often
share many of the same acoustic attributes: high energy and intensity, periodic waves,
and clear and stable formant structure. In a word like cebolla (“onion”), for example, the
exact boundary of the [o] positioned between the approximants [β] and [j] is difficult to
locate because of the spectral similarity of the three sounds. In order to ensure
consistency in the segmentation, vowels in these types of contexts were avoided.
Vowels in the context of the voiced approximants [β,ð,ɣ] were included only if a clear
boundary could be determined based on decreased intensity in the waveform.
Individual speaker characteristics, most notably creaky voice, prevented certain
tokens from being analyzed. Creaky voice is a type of phonation that, unlike modal
voicing, is characterized by irregular glottal pulsation.55 This irregularity makes reliable
extraction and systematic analysis of the formants very difficult. In addition, the goal of
the present dissertation is to describe the production of vowels with modal voicing, and
not to provide an analysis of creak. For these reasons, creaked vowels, as well those that
55 For further information pertaining to creaky voice, see Johnson (2003, pp. 136-139).
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were produced with breathy voice or that were devoiced were not included in the
analysis.
Finally, in rare instances, it was necessary to exclude vowel tokens as a
consequence of speaker characteristics or equipment malfunction. If the participant
spoke too softly and devoiced a vowel, the sound analysis software was unable to provide
accurate and consistent readings of the speech signal. If the participant touched or moved
the microphone or cleared his or her throat during the production of a specific vowel, this
also obscured the speech signal making it impossible to obtain an accurate measure of the
formant structure. In other cases, especially in the narrative retelling task which involved
more rapid speech, initial vowels were deleted almost entirely and therefore could not be
analyzed. The first [e] in the phrase dos espejos (“two mirrors”), for example, was
subject to deletion in Mexican speech because it is atonic and was positioned after a
sibilant consonant. Several of the participants simply did not produce this vowel, or what
was produced was too short to analyze or completely devoiced.56 Only vowels last had
durations of at least 40 milliseconds were included in the overall analysis. Further
explanation of duration is provided below in section 3.4.1.4.
3.4.1.3 Formant frequencies
In order to provide a descriptive account of the vowel system of heritage speakers
of Spanish, the first, second, and third formant frequency measures in Hertz of each of
the segmented vowels were extracted using an automated Praat script created by Lennes
56 Vowel reduction, devoicing, and deletion are known to be somewhat common in this phonetic environment, especially within the Andean and Mexican varieties (Matluck, 1952; Lope Blanch, 1972; Lipski, 1994; Delforge, 2008; Hualde, 2005).
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(2003) and modified by Todt (2009).57 As described previously in chapter 2, the first
formant frequency (F1) is the acoustic correlate of vowel height; high vowels are
characterized by a low F1 whereas low vowels are characterized by a high. The second
formant frequency (F2) is the acoustic correlate of vowel backness. Front vowels, such
as /i/ and /e/ have higher F2 values whereas the back vowels /o/ and /u/ have lower F2
values. Several investigations of Spanish vowels have shown that the first two formant
frequencies are sufficient to distinguish all of the members of the five vowel system
(Hualde, 2005; Martínez-Celdrán, 1995; Quilis & Esgueva, 1983), and therefore, only the
first two formant frequencies will be analyzed in the present study.
Formant frequency measures of each vowel were taken at three different points
within the vowel: the 25% point, the 50% point, and the 75% point as calculated by
Praat. The midpoint of the vowel is the preferred point of analysis because it is the
farthest removed from the surrounding consonantal context and is thus less subject to
coarticulatory effects from neighboring consonants. Only the formant measurements
taken at the 50% point will be reported in chapter 4, and not those taken at the other
points within the vowel.58
Praat settings and maximum formant settings were adjusted as needed for each
speaker and for each vowel. The typical maximum frequency was 5500 Hz and the
dynamic range was set at 40. The number of formants analyzed ranged between 4 and 6
57 The third formant frequencies were measures by the automated script, but will not be discussed in the present study. The third formant (F3) is typically associated with rounding, r-coloring, and retroflexion. As rounding is not a contrastive feature in Spanish, this measure is not necessary to distinguish Spanish vowels. Future studies could focus on examining the similarities and differences in rounding between HS, monolingual Spanish speakers, and monolingual English speakers. 58 The measures taken at the 25% and the 75% points within the vowel will allow for further investigation of the effects of surrounding consonantal context on vowel production. Analyzing the formant values at the 75% point within the vowel, for example, may reveal additional quality differences between vowels in open and closed syllables. Thus, the additional measurements taken within the vowel will not be discussed in the present study but will provide the basis for future investigations of heritage Spanish vowels.
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depending on the speaker’s gender and if the vowel was front or back. The
measurements extracted from the Praat script were written to a text file and then
transferred to Microsoft Excel for further analysis.59
3.4.1.4 Vowel duration
The duration of each segmented vowel was calculated in using a script written by
Lennes (2002) for Praat (Boersma & Weenink, 2010). The automated script measured
the duration of all vowels as they were labeled on the second tier of the text grid. The
output of the script was written to a text file, which was then transferred to Microsoft
Excel and sorted by vowel label. Vowels with extremely short durations (less than 40
ms) and long durations (greater than 110 ms) were hand-checked a second time to ensure
that the boundaries had been placed appropriately. The duration measurements extracted
by the Praat script were then submitted to statistical analysis to determine if stress,
syllable type, or task had a significant effect on the duration of Spanish vowels.
3.4.1.5 Vowel dispersion
In order to determine the degree of vowel dispersion within the acoustic space, the
center point of the vowel space, or “centroid,” was calculated for each individual speaker
using a process similar to the S-Centroid procedure described by Watt and Fabricius
(2002). The center of the vowel space was determined by calculating the average F1 and
59 The Praat script had default settings that could be adjusted overall for each speaker, but the maximum number of formants could not be altered for each individual vowel. Given the need to change the maximum number of formants analyzed by Praat depending on the vowel, many of the tokens were analyzed by hand using the “get formant” procedure from the drop down menu in Praat. The back vowel /u/ was especially problematic because the F1 and F2 values are positioned very close to one another. In some cases, the Praat script identified the third formant as the second, and reported an incorrect value. For this reason, all of the back vowels were carefully checked and hand-corrected. If the F2 of a back vowel was considerably out of range for an individual speaker (i.e., in the range of 2000Hz when all others had been near 1100-1200 Hz), the vowel was reexamined and the settings in Praat adjusted so that the formant tracker aligned with the second formant frequency and not the third.
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F2 frequencies of the point vowels /i,a,u/ in tonic, open syllables produced in the CPT.60
The average F1 and F2 values of the point vowels determined a center point in the
acoustic space that was unique to each individual. The Euclidean distance of each of the
individual’s vowels was then measured relative to the centroid. The formula to calculate
the Euclidean distance is presented in Equation 1 below. The distance (d) of p
(individual vowel) from q (the centroid) was calculated by taking the square root of the
sum of the squared difference between the F1 value of the individual vowel and the F1 of
the centroid, and the F2 of the individual vowel and the F2 of the centroid.
d(p,q) = √(p1 – q1)2 + (p2 – q2)2
Equation 1. Euclidean distance formula utilized to measure the distance of vowels from the center of the vowel space.
The calculation of the Euclidean distance thus permitted an examination of how
far away, or dispersed, each individual’s vowels were situated from the center of the
vowel space by providing a single value in Hertz. A pictographic representation of the
center of the vowel space and the distance of the point vowels from the center is
presented in Figure 3-11. The “X” marks the location of the hypothetical centroid, and
the dashed lines represent the Euclidean distance of the point vowels from the center.
Note that this illustration does not include the mid vowels and is meant to represent a
hypothetical vowel space. In a perfectly triangular vowel space such as the one
60 Previous analyses from the pilot experiment indicated that the tonic vowels in open syllables produced in the CPT were the most peripheral. In order to calculate the truest center of the vowel space, the F1 and F2 values from the most peripheral and extreme vowels were used as opposed to the average of the point vowels extracted from all three tasks.
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represented below, the Euclidean distance values of the point vowels from the center of
the space would be equal, as would the distances of the mid vowels from the center.
Figure 3-11. Representation of the centroid and distance of the point vowels from the centroid.
The Euclidean distance of the individual vowels from the center of the vowel
space was included as an additional dependent variable in the statistical analysis along
with the F1, F2, and duration of each speaker’s vowels. The statistical analyses are
discussed in detail in section 3.4.3.
3.4.1.6 Normalization
Normalization is a process that is traditionally performed on vowel formants in
order to remove differences in vowel formant frequencies that are a consequence of
physiology. That is, as males and females, as well as adults and children, have different
vocal tract sizes, the frequency ranges characterizing their vowels are inherently
different. In most acoustic studies of vowels where male and female speakers or adult
and child speakers are analyzed, it is important to remove as many of these differences as
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possible so that the different groups can either be pooled and analyzed together or
compared to other speaker populations. As this investigation includes male and female
speakers, the raw formant data were normalized using the NORM vowel normalization
suite (Thomas & Kendall, 2007). The Lobanov (1971) method of normalization was
employed because it outperformed other methods of normalization, more accurately
reducing physiological differences while at the same time maintaining sociolinguistic
differences between speakers (Adank, et al., 2004). The normalized vowels were then
scaled to a vocal tract model in NORM, thus resulting in formant values that represented
the overall vowel space of all the heritage speakers who participated in this study.61
3.4.2 Individual variables
In addition to examining the influence of stress, syllable type, and speech style on
vowel production, a second goal of this investigation was to determine the relationship
between several individual variables and HS vowel pronunciation. This information was
gathered based on the language background questionnaire, the grammar proficiency
activity (Geeslin & Gudmestad, 2010), and the cultural sensitivity questionnaire
(Cushner, 1986) described earlier in this chapter. Each of these variables is described in
greater detail below.62
61 As is discussed in section 3.4.3.2, the final statistical model and the results reported in chapter 4 pertain to the non-normalized data (i.e,. those that were NOT normalized with the Lobanov (1971) normalization procedure). Statistical tests were conducted with both the Lobanov normalized and non-normalized formants, however, and some reference is made to the Lobanov normalized data in chapter 5. A comparison of the statistics conducted with the normalized and non-normalized data are presented in Appendix L. 62 The language background questionnaire also included a series of statements and further information about whether or not each participant spoke another language, how well they spoke another language, and demographic terms they felt best described them (e.g., latino/a, mexico/a, americano/a, etc.) This additional information was excluded from the analysis given the similarity of the responses provided by the participants. For example, it was intended to examine how strongly each speaker felt that speaking Spanish helped them feel connected to their heritage. As all speakers responded with either “strongly agree” or
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3.4.2.1 Course level
The participants in this study were divided into two groups based on the Spanish
course-level in which they were currently enrolled. At the time of the investigation,
seven participants were enrolled in an intermediate-level Spanish course designed for
heritage speakers. The other nine participants had already completed this course and
were enrolled in upper 200-level or 300-level courses in literature, culture, or linguistics.
As the distribution of the participants was roughly even, their course level was one of the
variables included in the analysis. Course level was included in the statistical model as a
categorical covariate, meaning that each participant belonged to either the intermediate
group or the advanced group. The inclusion of course level as a variable may help
determine if greater or lesser degrees of overt language instruction influence the
pronunciation of HS vowels.
3.4.2.2 Grammar proficiency
As mentioned in chapter 2, an additional factor which could influence
pronunciation is a speaker’s grammar proficiency, or knowledge of formal grammar. In
order to examine the relationship between formal grammatical knowledge and
pronunciation, all participants completed a contextualized grammar activity designed by
Geeslin and Gudmestad (2010). This activity consisted of 25 multiple choice questions
which examined knowledge of object pronoun use, preterite and imperfect, ser and estar,
and conditional clauses, among other aspects of Spanish grammar. Each participant’s
“agree,” there was not enough variation in the responses to include this question in the analysis. There was very little variation in the selection of demographic terms, resulting in the same complication. Some participants indicated that they identified with all terms, whereas others indicated that they self-identified with just one term. Thus, the intention was to include more individual information in this portion of the analysis, but as there was very little variation between the speakers and a small number of total speakers, only the ICCS, grammar score, travel frequency, course level, and Spanish use were analyzed statistically.
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score on this proficiency test was included in the statistical analysis to determine if
knowledge of formal Spanish grammar impacted HS vowel quality and/or quantity. The
grammar score was included as a continuous covariate, meaning that each individual
speaker’s score was entered into the model separately. In other words, the participants
were not grouped into low, mid, or high proficiency levels as is typical in previous
studies. As will be discussed further in section 3.4.3, the parameter estimates of fixed
effects were examined in order to determine the relationship between grammar
proficiency score and HS vowel production.
3.4.2.3 Travel abroad
The frequency with which each speaker traveled abroad to their country of
heritage or another Spanish-speaking country was obtained from the language
background questionnaire. The responses provided by each participant helped divide
them into 3 groups. The four speakers who indicated that they had never traveled abroad,
or had not done so in the past 8 years, were grouped into the “no travel group” (group 0).
Those who indicated that they visited a Spanish-speaking country every 3-4 years formed
the “infrequent/some travel” group (group 1, N=6). Finally, those participants who
indicated that they traveled every year formed the “frequent travel” group (group 2,
N=6). Travel abroad was included in the statistical model as a categorical covariate,
which will be described in greater detail in section 3.4.3. The group scores were entered
into the analysis to determine if frequency of travel abroad influenced the way in which
these speakers pronounced their Spanish vowels.
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3.4.2.4 Spanish use
The language background questionnaire also contained a series of multiple choice
questions inquiring about how frequently each participant spoke or used Spanish in a
variety of contexts. The participants were asked to indicate how frequently (i.e., daily,
weekly, monthly, every few months, almost never) they spoke or used Spanish with
friends, family, watching television, reading books or magazines, listening to music or
the radio, watching movies, at the work place, and in school/class. For each category in
which the speaker indicated that they used Spanish daily, they were assigned the score of
“5,” for weekly a “4,” and so forth. The eight contexts and five degrees of use resulted in
a total possible score of 40. The higher the score, the more frequently Spanish was used.
Each participant was assigned their own individual Spanish score based on their
responses that was then included in the statistical analysis as a continuous covariate. The
goal of including this variable was to determine if speaking Spanish more or less had an
impact on how the Spanish vowels were pronounced.
3.4.2.5 Cultural Sensitivity
The final individual variable analyzed in this dissertation was the measure of
cultural sensitivity obtained via Cushner’s (1986) Inventory of Cross-Cultural Sensitivity
(ICCS). As described previously, participants were asked to rate a series of statements on
a scale of 1-7 to indicate their level of agreement or disagreement. The responses were
then organized into several different subscales (e.g., Cultural Integration, Behavioral,
Intellectual, Attitude, and Empathy), and the sum of the subscales resulted in the total
cultural sensitivity score. Given that the sample size in this investigation is small, only
the total ICCS score was submitted to the statistical analyses, and the not the individual
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subscale totals. As with grammar proficiency and Spanish use, the ICCS total was
included in the statistical model as a continuous covariate.
3.4.3 Statistical analyses
The purpose of this section of the chapter is to discuss the dependent and
independent variables, the way the data were coded, and describe the statistical analyses
that were conducted with the normalized and non-normalized data.
3.4.3.1 Variables and coding
Prior to describing the variables and the coding procedure, it is important to first
briefly summarize the research questions investigated in this dissertation. A summarized
version of each of the questions is presented below:
1) What is the basic distribution and organization of HS Spanish vowels within the acoustic space?
2) What is the role of lexical stress (i.e., tonic vs. atonic) in determining vowel height (F1), vowel backness (F2), vowel dispersion (Euclidean distance), and vowel duration?
3) How does syllable type (i.e., closed vs. open) influence vowel height (F1), vowel backness (F2), vowel dispersion (Euclidean distance), and vowel duration?
4) What is the connection between speech style (i.e., spontaneous, semi-spontaneous, and controlled) and vowel height (F1), vowel backness (F2), vowel dispersion (Euclidean distance), and vowel duration?
5) What is the relationship between a participant’s course level, grammar proficiency, travel frequency, Spanish use, and cultural sensitivity and vowel height (F1), vowel backness (F2), vowel dispersion (Euclidean distance), and vowel duration?
Based on the research questions presented above, the dependent variables in the
statistical analyses were F1, F2, Euclidean distance, and duration. The independent
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variables were subdivided into two groups: within-subjects variables and between-
subjects variables. The within-subjects variables included vowel, lexical stress, syllable
type, and speech style. The between-subjects variables included course level, grammar
proficiency, travel frequency, Spanish use, and cultural sensitivity.63 Whereas all of the
within-subjects variables were categorical, meaning vowels were either tonic or atonic, in
closed or open syllables, or produced in one of the three speech styles, the between-
subjects variables were both categorical and continuous. The categorical between-
subjects variables included course level (intermediate or advanced) and travel frequency
(never, infrequent, or frequent). Grammar proficiency, Spanish use, and cultural
sensitivity were continuous covariates, meaning that the scores varied along a continuum
and were not grouped together in any specific way.
Each individual vowel was coded based on the lexical stress category in which it
occurred, the syllable type in which it occurred, and the speech style in which it was
produced. Furthermore, the vowels were coded by each of the individual variables
relevant to the particular speaker who produced the vowel. The coded vowel tokens were
then submitted to a series of Mixed Linear Models with a random effect of speaker,
which is explained in greater detail in the following section.
3.4.3.2 Statistical analyses and final model
Determining which statistical analyses, and which variables and interactions to
include in the analyses, was not a straightforward process. Several different types of
statistical analyses were carried out on the data prior to deciding which statistical test 63 Within-subjects variables are factors in which the subject is tested on each level of the variable. Lexical stress, for example, has two levels, and each subject is tested on each level of the variable. That is, each speaker produced both tonic and atonic vowels. Between-subjects variables are independent variables in which a different group of subjects is tested on each level of the variable. Gender is an example of a between-subjects factor because the participants could only belong to one group: either male or female.
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should be conducted and which interactions should be included. Three different rounds
of statistics were conducted on the data: separate 4-Way ANOVA’s for each individual
speaker, a Mixed Linear model with the random effect of speaker on the formant values
that had been normalized using the Lobanov (1971) method of normalization, and a
Mixed Linear Model with the random effect of speaker on the non-normalized formant
values.64 The final option (i.e., Mixed Linear Model with random effect of speaker on
non-normalized data) was selected as the statistical method for this data
The Mixed Linear Model was selected as the preferred statistical method for three
main reasons. First of all, this model permitted the inclusion of all variables (i.e., within-
and between-subjects variables) in a single analysis, therefore providing the ability to
make greater generalizations across the population. Second of all, the Mixed model
allowed for the analysis of both fixed effects and random effects. Including the random
effect of “speaker” in the model accounted for individual variation in vowel production in
much the same way that a traditional normalization procedure would. For this reason, the
64 Prior to deciding upon the Mixed Linear Model, separate four-way ANOVA’s, one for each of the dependent variables (F1, F2, duration, and Euclidean distance) were calculated for each individual speaker. A full-factorial design was conducted, thus including interactions between all of the independent variables. The results of each of the individual results were then compared to one another to gain an overall picture of which main effects and interactions consistently occurred across the group of speakers. This method of analysis, however, would not have allowed for a general picture of HS vowel pronunciation. Comparing the analyses conducted on completely different sets of data without taking into consideration the range of variation exhibited by each speaker in terms of formant values or the potential differences in speaking rate is not a meaningful comparison and does not allow for generalization. In addition, a simple ANOVA model would not have allowed for an analysis of the effects of individual variables on vowel pronunciation because each speaker could only belong to one group or one level. The inability to include between-subjects variables in the ANOVA thus resulted in it being ill-suited for this investigation. The full-factorial model also proved to be problematic, as some of the interactions were not meaningful and did not address the research questions. The interaction between stress and syllable type on the F2 dimension, for example, would not have provided a meaningful result. An interaction of this type would only reveal that the F2 values were higher or lower in certain syllable types based on lexical stress, but as front and back vowels are characterized by very different formant frequencies, the outcome would have been misleading or uninterpretable. An overall effect of stress according to syllable type without taking into consideration which vowel or vowels were being affected would not have offered insight into the effect of this variable on the HS vowel system. For these reasons, the use of ANOVA’s was not selected as the primary statistical method in this investigation.
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raw formant values were entered into the model and statistically analyzed, and not those
that were first normalized with the Lobanov (1971) method.65 Third of all, this model
allowed for a custom design, so that only meaningful main effects and interactions could
be included.
Mixed Linear Models with a random effect of speaker were conducted separately
on non-normalized F1, F2, Euclidean distance, and duration and were custom designed so
that they only included the independent variables and covariates that were needed to
address the research questions. A full-factorial model was not used, as this would have
included too many factors and would have diminished statistical power. All main effects
were included in the final model for both the within-subjects (i.e., vowel, stress, syllable
type, and task) and between-subjects variables (i.e., group, gender,66 grammar score,
travel abroad, Spanish use, and cultural sensitivity). All simple interactions between
vowel and the other within-subjects variables, as well as three-way interactions between
vowel, task, and stress and vowel, task, and syllable type were included in the statistical
65 The decision to report the analyses conducted with the non-normalized data was motivated by several reasons. First and foremost, as mentioned in text, the random effects component helped account for individual speaker variation. With random effects included, the model created a separate intercept for each individual speaker, thus recognizing that each participant was a different speaker and should be treated differently. The formant values were therefore adjusted statistically to reflect the variation present in the data. A second reason for maintaining the formant values in their original form and not normalizing is that no direct comparisons between speakers or between genders were made in the present study. The distribution of male and female participants was too unequal for a meaningful comparison. As one of the main purposes of normalization is to account for variation in formant frequencies due to physiology, and the comparison between genders was not made, the need to normalize was not as extreme as it would have been if the vowel spaces of male and female HS were being compared. One of the primary differences between the random effect of speaker and a traditional normalization procedure is that the speaker effect did not scale the formant values. The lack of scaling, however, was not problematic, especially because the NORM normalization suite cautions against scaling data, arguing that it may not be accurate. The disadvantage of the random effect is that it does not control for between-subjects variation as well as a formal normalization procedure would. Thus, as expected, a gender effect was observed in the analysis of the non-normalized data that is partially removed in the analysis of the Lobanov (1971) normalized data. A comparison between the statistical results calculated with the normalized and non-normalized data are presented in Appendix L. As illustrated in the table of results presented in Appendix L, there were very few differences in the results conducted with the normalized and non-normalized data. 66 Gender was included in the model to remove some of the variance and to test the effectiveness of the normalization procedure.
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model. Two-way interactions between vowel and each of the between-subjects variables
were also included (i.e., vowel and travel, vowel and Spanish use, etc.) in the statistical
analysis. No additional interactions were included in the final model in order to prevent
the model from over-fitting the data. The final statistical model included the main effects
and interactions presented in Table 3-1 below, with the “X” denoting an interaction.
Table 3-1
Variables included in Mixed Linear model Main effects Interactions Within-subjects Between-subjects Within-subjects Between-subjects
Vowel Course level Vowel X stress Vowel X course level
Stress Grammar score Vowel X syllable type Vowel X grammar score
Syllable type Travel abroad Vowel X task Vowel X travel abroad
Task Spanish use Vowel X task X stress Vowel X Spanish use
C2 manner Cultural sensitivity Vowel X task X syllable type
Vowel X cultural sensitivity
C2 voice Gender Note. C2 manner and C2 voice were only included in a second analysis conducted with duration. “C2 manner” refers to the manner of articulation of the following consonant, and “C2 voice” refers to the voicing characteristics of the following consonant.
Chapter four reports the statistical results of the analyses conducted on each of the
dependent variables.
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4 RESULTS
This chapter presents the results of the statistical analyses described in chapter three.
Section 4.1 begins with summary information (i.e. mean, standard deviation) for each of
the dependent variables, and subsequently reports the effects of the within-subjects
variables (i.e., lexical stress, syllable type, and speech style) on the dependent variables.
The statistical results of the between-subjects variables (i.e., course level, frequency of
travel, grammar proficiency, Spanish use, and cultural sensitivity) are described in
section 4.2. An overall summary of results is presented in section 4.3. The total number
of vowel tokens analyzed in this dissertation and their distribution in each of the within-
subjects variable categories are presented in Appendix G. All of the statistical outputs
are included in Appendices H-K.
4.1 Within-subjects variables
Prior to describing the statistical results, the mean formant values, Euclidean
distances, and duration of vowels produced by the male and female participants are
presented in Tables 4-1 and 4-2. As the values are raw and not normalized or adjusted by
the statistical model, male and female data are presented separately. The tables include
the number of cases, mean, and standard deviation of F1, F2, Euclidean distance, and
duration of each vowel averaged across all male and female speakers, respectively.
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Table 4-1
Basic characteristics of vowels produced by three male heritage speakers
F1 F2
Euclidean distance Duration
Vowel N Mean S.D. Mean S.D. Mean S.D. Mean S.D.
/a/ 172 652.67 73.62 1449.18 135.87 203.70 100.21 77.87 23.06
/e/ 154 474.32 47.57 1777.03 183.90 261.31 149.07 64.75 20.73
/i/ 120 350.42 41.59 2109.45 186.07 578.82 193.17 59.60 17.58
/o/ 111 506.71 42.82 1085.08 110.65 452.94 109.98 68.79 23.73
/u/ 82 398.18 37.38 1099.27 199.92 452.30 180.22 69.02 23.50
Note. The values are raw averages (Mean) and standard deviations (S.D.) that have not been adjusted by the statistical model. Formant values and the Euclidean distance are measured in Hertz. Duration is measured in milliseconds.
Table 4-2
Basic characteristics of vowels produced by thirteen female heritage speakers
F1 F2
Euclidean distance Duration
Vowel N Mean S.D. Mean S.D. Mean S.D. Mean S.D.
/a/ 765 778.50 103.94 1580.93 164.26 322.29 106.00 88.96 29.83
/e/ 642 548.98 72.07 1958.21 241.55 272.43 169.27 74.54 28.37
/i/ 484 383.86 53.38 2500.04 277.18 772.04 242.91 70.37 23.67
/o/ 444 573.29 71.81 1139.53 176.52 615.64 154.66 78.21 27.85
/u/ 368 429.31 52.25 1180.04 256.39 594.40 221.99 73.96 29.18
Note. The values are raw averages (Mean) and standard deviations (S.D.) that have not been adjusted by the statistical model. Formant values and the Euclidean distance are measured in Hertz. Duration is measured in milliseconds.
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The remainder of this section reports the statistical results of the within-subjects
variables that were included in the Mixed Linear Models.67 The results will be further
divided by the main effects and simple interactions (section 4.1.1), and complex
interactions (4.1.2). Within each sub-section, the effect of the independent variables on
vowel quality (F1 and F2), Euclidean distance, and duration will be discussed in that
order.
4.1.1 Main effects and simple interactions
4.1.1.1 Vowel The independent variable of vowel was included in order to 1) examine how HS
vowels are organized by height and backness, 2) assess if they exhibit durational
differences, and finally 3) address how they are organized or dispersed within the
acoustic domain relative to the center of the vowel space. The effect of vowel was found
to have a significant effect on all four dependent variables, each of which will be
discussed in greater detail below. Only the main effect of vowel will be discussed in this
section, meaning that the results are collapsed across all stress, syllable, and task types.
The significant interactions involving vowel will be discussed in greater detail later on in
this chapter.
A total of 3,342 vowels were analyzed via the Mixed Linear Model. The
statistical analyses indicated that there was a significant main effect of vowel on both F1
and F2, indicating that the five Spanish vowels differed from one another in terms of
height and backness. As will be discussed later on in this section, the Euclidean distance
67 As a reminder, the raw F1 and F2 values in Hertz were calculated for each speaker, the Euclidean distance of the vowels from the centroid of each speaker’s vowel space was calculated based on the F1 and F2 of the point vowels, and the total duration in milliseconds was measured for each vowel. The results presented in this chapter are based on the estimated marginal means calculated by the Mixed Linear Models and include all speakers unless otherwise indicated.
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measures also differed for each vowel. The F1, F2, and Euclidean distance measures of
each of the five Spanish vowels are presented in Table 4-3. The table presents the
estimated marginal means calculated by the statistical model, and not the raw averages
produced by all speakers.68
Table 4-3
F1, F2, and Euclidean distance measures of HS vowels
Vowel F1 (Hz) F2 (Hz) Euclidean Distance (Hz)
/i/ 687.81 2207.13 573.50 /e/ 499.14 1893.06 276.73 /a/ 687.81 1529.55 239.50 /o/ 537.44 1166.03 489.56 /u/ 420.64 1208.83 462.14
The overall distribution of the vowels is shown in Figure 4-1. A more in-depth
description of the differences between the vowels is provided below the figure.
68 Unless otherwise indicated, all tables and figures presented in this chapter present the estimated marginal means determined by the statistical model and not the raw averages. Standard deviations are not included because these are estimated marginal means and not the raw averages. Standard deviation is used to describe the variance within the population, and would need to be based off of the raw averages.
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Figure 4-1. Overall acoustic distribution of HS vowels averaged across all speakers, stress contexts, syllable types, and tasks (N = 3,3,42).
The Mixed Linear Model with F1 as the dependent variable indicated a significant
main effect of vowel (F(4, 3254.08) = 16.56, p < .001), confirming that the HS vowels
were distinguished from one another in terms of vowel height. A closer examination of
this effect via pairwise comparisons indicated that the HS vowel system exhibits five
statistical degrees of height. The low vowel /a/ exhibited the highest F1 and was
articulated significantly lower in the vowel space than all other vowels (F1 = 687.81 Hz,
p < .001). The mid vowel /o/ was significantly higher than /a/ and significantly lower
than all other vowels with a value of 537.44 Hz (p < .001). The front mid vowel /e/ was
significantly higher than /o/ and /a/ and significantly lower than /i/ and /u/, with an
average F1 value of 499.14 Hz (p < .001). The high vowels /i/ and /u/ were significantly
higher than all other vowels, but differed significantly from each other in terms of their
relative height. The back vowel /u/ was produced with the second lowest F1 value
(420.64 Hz) and the front vowel /i/ with the lowest F1 value (368.35 Hz, p < .001).
/i/
/e/
/a/
/o/
/u/
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400
500
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F1 H
z
F2 Hz Overall vowel space
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Thus, unlike traditional descriptions of the Spanish vowel system which argue for three
degrees of height, the HS vowel system exhibits five degrees. These differences are
represented in Figure 4-1.
The main effect of vowel on F2 was also significant (F(4, 3254.13) = 19.22, p <
.001), indicating the HS vowels were also distinct with respect to backness. Pairwise
comparisons of this main effect revealed four distinct degrees of backness. The front
vowels /i/ and /e/ were distinct from one another, with /i/ exhibiting the highest F2
frequency (2207.13 Hz) followed by /e/ (1893.06 Hz). The front vowels differed
significantly from each other and from all other vowels in terms of backness (p < .001).
The central vowel /a/ was distinct from all other vowels with an average F2 value of
1529.55 Hz (p < .001). Finally, the back vowels /o/ and /u/ were articulated significantly
farther back in the vowel space than all other vowels (p < .001) but did not differ
significantly from each other (p = .204). The /o/ was produced with an average value of
1166.03 Hz, and the /u/ with an average value of 1208.83 Hz. That the /u/ was produced
farther front in the vowel space than the /o/ conflicts with what is typically described for
the Spanish vowel system (see sections 2.2.2 and 2.2.3 concerning Spanish vowel
systems). Generally /u/, and not /o/ is argued to be articulated farthest back in the vowel
space. As these vowels did not differ statistically from one another, however, indicates
that for this group of HS, the back vowels occupy roughly the same region within the
acoustic space. The front vowels, on the other hand, differed significantly from one
another with respect to backness. Thus, a distinction in vowel backness was observed in
the higher frequency ranges for the front vowels, but not for the back vowels. The
differences in vowel backness can also be observed in Figure 4-1. Two characteristics
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that stand out in this figure that differ from traditional characterizations of Spanish vowel
systems are the backing of /e/ and its overall distance from the high vowel /i/, as well as
the fronting of /u/.
The analysis conducted on the Euclidean distance measure indicated a significant
main effect of vowel (F(4, 3254.14) = 5.06, p < .001), revealing that HS vowels were
distributed differently with respect to the centroid (see Table 4-3 for values, and section
3.4.1.5 for the Euclidean distance formula). The overall vowel space, centroid, and
Euclidean distance of each vowel are represented in Figure 4-2. The values presented
here are based on the estimated marginal means tabulated for all subjects combined.69
Figure 4-2. Overall dispersion of HS vowels averaged across speakers, stress, syllable, and task (N=3,342).
69 Figure 4-2 represents the Euclidean distance calculated based on the estimated marginal means across all speakers. It is important to note that the statistical analysis conducted on the Euclidean distance was calculated based on each speaker’s Euclidean distance measure. That is, a centroid and Euclidean distance was calculated for each participant separately, and these measures were submitted to the statistical test. What is presented in the figure is a means of illustrating the overall trend observed by all speakers separately, and was the most cohesive way of representing this measure as opposed to including 16 separate vowel charts.
300
400
500
600
700
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F1 H
z
F2 Hz
Overall vowel space with centroid
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A closer examination of the Euclidean distance measures calculated for all vowels
via pairwise comparisons indicated that all vowels differed with respect to their proximity
to the centroid except for /u/ and /o/. The vowel situated closest to the centroid was /a/
(239.50 Hz), and this difference was significant from /e/ at the level of p = .013 and from
all other vowels at the level of p < .001. The mid vowel /e/ had the second smallest
Euclidean distance (276.73 Hz), differing significantly from /a/ at p = .013 and from all
other vowels at p < .001. The Euclidean distance of the back vowels /u/ and /o/ were
462.14 Hz and 489.56 Hz, respectively. As mentioned previously, these distances were
not significantly different from one another (p = .661), but were significantly different
from all other vowels (p < .001). Finally, the front vowel /i/ exhibited the greatest
Euclidean distance, indicating that it was articulated farthest from the centroid, and
farther than any other vowel (573.50 Hz, p < .001). The results of this analysis thus
demonstrate that HS vowels are not distributed evenly throughout the acoustic space with
respect to the centroid. This finding conflicts with arguments that the Spanish vowel
system is symmetrical in nature.
An examination of the overall vowel space and centroid indicate that /a/ was
produced closest to the center of the vowel space than any other vowel. The figure
representing this distribution, Figure 4-2, however, is somewhat misleading given the
scale on which F1 and F2 are represented. Based solely on the graphical representation
of the vowels of the centroid, the mid vowel /e/ appears to be the closest. If the F1 and
F2 scales are made identical, however, the proximity of /a/ to the center of the vowel
space becomes more apparent. Figure 4-3 provides a more accurate representation of the
proximity of the vowels to the center of the space.
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Figure 4-3. Overall dispersion of HS vowels with adjusted scale.
Finally, the statistical analysis of duration revealed a significant main effect of
vowel, indicating that the vowels differed from each other with respect to duration across
differences due to task, stress type, or syllable type in which they were produced (F(4,
3254.16) = 3.80, p = .004). The average duration in milliseconds of all vowels are
presented numerically in Table 4-4.
Table 4-4
Overall HS vowel duration
Vowel Duration Standard Error
/i/ 61.67 3.77 /e/ 68.80 3.71 /a/ 79.61 3.66 /o/ 70.05 3.73 /u/ 65.83 3.93
A graphical representation of vowel duration is provided in Figure 4-4. The scale
of the graph is in milliseconds, and each bar represents the duration of one of the five
30050070090011001300150017001900210023002500
30050070090011001300150017001900210023002500
F1 H
z
F2 Hz
Overall vowel space with centroid
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Spanish vowels averaged across all speakers, stress contexts, syllable types, and tasks.
Standard error bars are also included in the figure.70
Figure 4-4. Overall vowel duration for all speakers averaged across stress, syllable type, and task. (N = 3,342). The low vowel /a/ was the longest vowel with an average duration of 80
milliseconds, and differed significantly in length from all other vowels (p < .001). The
mid vowel /o/ exhibited the second longest duration (79 milliseconds) and differed
significantly from /i/ (p = .001) and / a/ (p < .001). The front mid vowel /e/ was produced
with an average duration of 69 milliseconds, and was significantly longer than /i/ (p =
.005) and shorter than /a/ (p < .001). The high vowels /i/ and /u/ exhibited the shortest
duration and were significantly shorter than all vowels but did not differ from each other.
The front vowel /i/ was significantly shorter than /a/ (p < .001), from /e/ (p = .001), and
70 Standard error bars are included on this graph, as opposed to standard deviations, because the values are the estimated marginal means based on the model’s predictions. The standard error is used to show the variation within the sample, whereas the standard deviation is used to represent the variation within the population. One of the assumptions of this model, however, is equal variance. For this reason, the standard error bars are approximately the same size. The error bars will not be included on all of the charts for vowel duration that represent estimated marginal means.
0 10 20 30 40 50 60 70 80 90
/i/
/e/
/a/
/o/
/u/
Duration in ms
Overall vowel duration
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from /o/ (p = .005). The back vowel /u/ only differed significantly in length from /a/ (p <
.001). The results of this analysis indicate that HS Spanish vowels exhibit a degree of
intrinsic vowel duration similar to that described by Marín Gálvez (1995) for
monolingual Spanish. Generally speaking, vowel duration decreased with vowel height,
such that /a/ had the longest duration, the mid vowels /e/ and /o/ had intermediate
duration, and the high vowels had the shortest duration.
Another way of conceptualizing the intrinsic vowel duration is presented in
Figure 4-5. This figure represents the organization of the HS vowels within the acoustic
space. The size of each circle represents the vowel duration, with the largest circles
indicating longer duration and the smaller circles denoting shorter vowels.
Figure 4-5. Vowel duration based on acoustic distribution for all speakers averaged across stress, syllable type, and task.
To summarize briefly the main findings of this section, an examination of the
effect of vowel on F1, F2, Euclidean distance, and duration provide an overall view of the
organization of the HS Spanish vowel system. The analyses of F1 and F2 also revealed
/i/
/e/
/a/
/o/
/u/
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F2 Hz Vowel duration by acoustic distribution
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subtle differences in vowel height and backness (i.e., a five-level height distinction and a
four-level backness distinction) that are typically not described in impressionistic
accounts of Spanish vowel systems.71 The analysis of Euclidean distance showed that
not all vowels are organized symmetrically or evenly throughout the acoustic space,
questioning the assumption that Spanish possess a simple, symmetrical vowel system.
Finally, the results of duration are in line with previous accounts that vowel duration
decreases as vowel height increases (Marín Gálvez, 1995). Although /u/, /e/, and /o/ did
not differ significantly from one another with respect to duration, a basic pattern
emerged: /a/ > /e/ and /o/ > /i/ and /u/.
4.1.1.2 Stress
This section examines the effect of lexical stress on vowel quality, quantity, and
dispersion. The results of the statistical analysis revealed several important main effects
and interactions that will be explained further throughout this section. As with the
previous section, the results presented here reflect the stress effects observed for all
vowel categories collapsed over syllable type and task. An interaction involving vowel
category and stress indicates that a stress effect depended upon which vowel was being
produced. Both the main effects and simple interactions will be discussed below.
The F1, F2, and Euclidean distance measures of the atonic and tonic HS vowels
are presented in Table 4-5.
71 O’Rourke (2010) also noted a five-level distinction in both height and backness in Peruvian Spanish.
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Table 4-5
F1, F2, and Euclidean distance measures of HS vowels in each stress context
Vowel Stress F1 (Hz) F2 (Hz) Euclidean distance (Hz)
/i/ atonic 376.32* 2112.42* 483.60*
tonic 360.39* 2301.84* 663.41* /e/ atonic 465.18* 1872.56* 276.89
tonic 533.10* 1913.57* 276.58 /a/ atonic 647.83* 1524.60 214.47*
tonic 727.80* 1534.52 264.55* /o/ atonic 517.85* 1211.00* 440.54*
tonic 557.04* 1121.06* 538.59* /u/ atonic 420.42 1255.54* 421.66*
tonic 420.88 1162.13* 502.63* Note. The “*” denotes a statistically significant difference between tonic and atonic measures.
A graphical representation of the distribution of HS vowels based on stress type is
presented in Figure 4-6. The dashed lines represent the acoustic space occupied by the
atonic vowels, and the solid line represents the tonic vowel space. A detailed description
of the significant main effects and interactions is presented below the figure.
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Figure 4-6. Tonic and atonic vowel productions for all speakers averaged across syllable type and task.
The Mixed Linear Model with F1 as the dependent variable revealed a significant
main effect of stress (F(1, 3254.20) = 204.223, p < .001) and a significant vowel by stress
interaction for F1 (F(4, 3254.16) = 62.18, p < .001). The main effect of stress on F1
indicated that overall, vowels in atonic syllables had lower F1 values (485.52 Hz), or
were produced higher in the vowel space, than tonic vowels (519.84 Hz). The vowel by
stress interaction indicated that the difference in vowel height was significant for all
vowels except for /u/. A closer examination of vowel by stress interaction via pairwise
comparisons indicated that atonic /a/, /e/, and /o/ were produced with significantly lower
F1 values than when they occurred in tonic syllables (all comparisons p < .001). Thus,
the atonic productions of the non-high vowels were raised when atonic as compared to
tonic. The opposite pattern was observed for the high vowel /i/, which exhibited a
significantly higher F1 value (i.e., produced lower in the vowel space) when it occurred
in an atonic syllable (p = .004).
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Although there was no significant main effect of stress along the F2 dimension
collapsing across all vowels, the vowel by stress interaction was significant for F2 (F(4,
3254.24) = 46.59, p < .001). This interaction indicated that the effect of stress along the
front-back continuum depended upon the vowel. The pairwise comparisons indicated
that all vowels except for /a/ differed with respect to backness based on their stress type.
The front vowels /e/ and /i/ exhibited significantly lower F2 values in atonic productions
as compared to tonic productions, indicating that unstressed vowels had a more
centralized articulation than tonic vowels. Atonic /e/ was produced significantly farther
back in the vowel space when compared to tonic /e/ (atonic = 1872.55 Hz, tonic =
1913.56 Hz, p = .011), and the same pattern was observed for /i/ (atonic = 2112.42 Hz,
tonic = 2301.84 Hz, p < .001). The back vowels were also produced with a more
centralized articulation when compared to their tonic counterparts. Atonic /u/ and /o/
were produced with significantly higher F2 values than tonic /u/ and /o/ (for /u/, atonic =
1255.54 Hz, tonic = 1162.13 Hz, p < .001; for /o/, atonic = 1211.00 Hz, tonic = 1121.06
Hz, p < .001). The differences between atonic and tonic vowel articulations with respect
to backness are also represented in Figure 4-6. As can be observed, the atonic vowel
space, represented by the dashed line, falls within the tonic vowel space. Thus, all atonic
vowels were centralized in comparison to their tonic counterparts.
The dispersion of the vowels throughout the vowel space, as measured by the
Euclidean distance of each vowel from the centroid, was also affected by lexical stress in
much the same way as F1 and F2 (see Table 4-5 for actual values). The Euclidean
distance measure is another way of representing the combined influence of F1 and F2 on
the positioning of vowels within the acoustic space. An illustration of the distance of
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each vowel from the centroid is represented in Figure 4-7, which includes the tonic and
atonic vowel spaces as well as the centroid measure.
Figure 4-7. Tonic and atonic vowel dispersion for all speakers averaged across syllable type and task.
The statistical analysis with Euclidean distance as the dependent variable revealed
a significant main effect of stress (F(1, 3254.39) = 190.06, p < .001) and a significant
vowel by stress interaction (F(4, 3254.30) = 25.01, p < .001). The main effect of stress
indicated that overall, atonic vowels had a shorter Euclidean distance (i.e., were closer to
the centroid) than were the tonic vowels (atonic= 367.43 Hz, tonic = 449.15 Hz). The
significant vowel by stress interaction showed that the proximity of atonic and tonic
vowels to the centroid varied for each vowel. With the exception of the mid vowel /e/, all
other vowels exhibited significantly shorter Euclidean distance measures when they were
produced in atonic syllables as compared to tonic syllables (for all vowels, p < .001).
The difference for /e/, however, was not significant, indicating that stress did not have an
effect on the location of this vowel with respect to the centroid (p = .981). These results
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are similar to those reported for F1 and F2, in that the atonic vowels were found to be
articulated closer to the center of the vowel space than the tonic vowels.
Moving on to vowel duration, the statistical analyses revealed that lexical stress
had a significant influence on vowel duration. The duration in milliseconds of the atonic
and tonic vowels produced by all HS averaged across tasks and syllable types are
presented in Table 4-6.
Table 4-6
Atonic and tonic vowel duration Vowel Atonic Tonic
/i/ 53.78 69.57 /e/ 53.85 83.75 /a/ 65.15 94.07 /o/ 56.38 83.73 /u/ 52.56 79.10
Note. The atonic vowels were always significantly shorter than their tonic counterparts at the level of p < .001.
The differences between atonic and tonic vowel duration are also represented
graphically in Figure 4-8. The gray bars represent atonic vowel duration, and the black
bars represent tonic duration.
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Figure 4-8. Tonic and atonic vowel duration for all speakers averaged across syllable type and task.
Lexical stress had a significant effect on vowel duration as evidenced by a
significant main effect of stress (F(1, 3254. 41) = 749.66, p < .001) and a significant
vowel by stress interaction (F(4, 3254.32) = 7.25, p < .001). The main effect of stress
indicated that across all vowels, task types, and syllable types, the tonic vowels were
significantly longer than the atonic vowels (tonic vowel duration = 82 milliseconds,
atonic vowel duration = 56 milliseconds). The vowel by stress interaction was also
significant, indicating that the effect of stress depended upon the vowel (see Figure 4-8).
The pairwise comparisons of the interaction indicated that for all vowels, the duration of
tonic vowels was significantly longer than the atonic vowels (for all vowels, p < .001).
To summarize the overall results of this section, the statistical analyses of F1, F2,
duration, and Euclidean distance indicated that lexical stress has a considerable effect on
HS vowel production. In terms of vowel quality, the non-high vowels were found to
have lower F1 values (i.e., were situated higher in the space). With respect to F2, the
0 10 20 30 40 50 60 70 80 90 100
/i/
/e/
/a/
/o/
/u/
Duration in ms
Tonic and atonic vowel duration
atonic
tonic
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atonic front vowels exhibited lower F2 values and the atonic back vowels higher F2
values than their tonic counterparts. This pattern resulted in a movement of unstressed
vowels towards the center of the space along the front-back dimension. This tendency to
centralize was reflected further based on the Euclidean distance measure. With the
exception of /e/, all atonic vowels exhibited significantly shorter distance measures than
the tonic vowels. Finally, tonic vowels were significantly longer in duration than atonic
vowels, and this distinction was statistically significant for all five of the vowel pairs.
Taken together, the results indicate that the HS vowel system shows reduction in terms of
quality and quantity. The presence of large stress differences conflicts with traditional
arguments that Spanish vowel quality and duration are fairly similar in tonic and atonic
syllables.
4.1.1.3 Syllable type
An additional component of the statistical model was to examine the effect of
syllable type on vowel height, backness, duration, and dispersion. The statistical analyses
revealed that there was no significant main effect of syllable type or simple interaction
between vowel and syllable type on F1. The lack of an overall main effect or simple
interaction indicated that vowels did not differ in vowel height based on the syllable type
in which they were produced. There was a significant three-way interaction involving
F1, however, which will be discussed in section 4.1.2.2.
The F1, F2, and Euclidean distances of the vowels produced in open and closed
syllables averaged across speakers, stress types, and tasks are presented in Table 4-7.
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Table 4-7
F1, F2, and Euclidean distance measures of HS vowels produced in open and closed syllables
Vowel Syllable type F1 (Hz) F2 (Hz) Euclidean
distance (Hz) /i/ closed 369.90 2189.15* 553.31*
open 366.81 2225.11* 593.70* /e/ closed 497.37 1878.47 259.58*
open 500.92 1907.65 293.89* /a/ closed 690.76 1549.88* 227.85*
open 684.87 1509.24* 251.17* /o/ closed 537.97 1181.24 474.71*
open 536.93 1150.82 504.42* /u/ closed 426.45 1235.70* 432.10*
open 414.85 1181.98* 492.19* Note. The “*” denotes a significant difference between vowels produced in open and closed syllables.
A graphical representation of the vowel pronunciation based on syllable type is
shown in Figure 4-9. The solid line represents the vowel space for vowels produced in
closed syllables, and the dashed line represents the open syllable vowel space. It is
important to note that although the lines appear to be generally overlapping, the statistical
analysis examines the amount of variation within each of these categories. Even though
many of the category averages appear to be situated in similar locations, the statistical
tests indicate that the closed and open vowel categories show greater or lesser amounts of
variance. The statistical results will be described in greater detail below the figure.
165
Figure 4-9. Acoustic distribution of vowels produced by all speakers in open and closed syllables averaged across stress and task.
The effect of syllable type was present along the F2 dimension as evidenced by
the significant vowel by syllable type interaction (F(4, 3254.15) = 5.83, p < .001). The
significant interaction between vowel and syllable type indicates that although syllable
type did not have an overall effect on F2, it did have an effect on certain vowels.
Pairwise comparisons of this interaction indicated that the F2 of /a/ produced in closed
syllables (1549.87 Hz) was significantly higher than the F2 of vowels produced in open
syllables (1509.24 Hz, p = .003). Thus, the /a/ in closed syllables was significantly
farther front than the /a/ produced in open syllables. A similar result was found for the
back vowel /u/, which also exhibited higher F2 values in closed syllables (1235.70 Hz)
than in open syllables (1181.97 Hz, p = .019). The opposite pattern was observed for the
front vowel /i/. In closed syllables, /i/ was produced with a significantly lower F2 value
(2189.15) than in open syllables (2225.114 Hz, p = .036). Thus, the /i/ in closed syllables
was articulated further back in the vowel space than /i/ in open syllables. What is most
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interesting about this result is that the mid vowels /e/ and /o/ did not exhibit any
significant differences with respect to syllable type, and these are the two vowels that are
traditionally argued to show allophonic variation based on syllable structure and the
nature of the following consonant (Navarro-Tomás, 1918).
Syllable type was also found to have a significant effect on the Euclidean distance
of vowels from the centroid. The Euclidean distance measures are presented above in
Table 4-7. Figure 4-10 represents the acoustic space occupied by vowels produced in
closed and open syllables, and includes the centroid as a point of reference.
Figure 4-10. Vowel dispersion based on syllable type.
The main effect of syllable type on Euclidean distance was significant (F(1,
3254.22) = 35.29, p < .001), indicating that across all vowels, stress, and task types, the
vowels produced in open syllables had greater Euclidean distances and were thus situated
farther from the centroid than vowels produced in closed syllables (closed syllables =
389.50, open syllables = 427.07 Hz). This difference was consistent for all vowels, and
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this consistency explains why the vowel by syllable type interaction was not found to be
significant: The distance of vowels produced in open and closed syllables did not depend
on the vowel because vowels produced in closed syllables were always closer to the
centroid.72 To conceptualize this effect in a different way, the vowels produced in open
syllables were more greatly dispersed than those produced in closed syllables.
Finally, the analyses of duration revealed both a significant main effect of syllable
type (F(1, 3254.24) = 9.3, p = .002) and a significant vowel by syllable type interaction
(F(4, 3254.19) = 4.28, p = .002). The duration in milliseconds of vowels produced in
open and closed syllables are presented in Table 4-8.
Table 4-8
Vowel duration in closed and open syllables
Vowel Open Closed /i/ 56.90* 66.44* /e/ 65.90* 71.69* /a/ 79.64 79.57 /o/ 68.93 71.18 /u/ 66.95 64.71
Note. The “*” denotes a significant difference.
The durational differences are further represented in Figure 4-11. The gray bars
represent vowels produced in open syllables, and the black bars represent the duration of
vowels produced in closed syllables. A more detailed explanation of the statistical
analyses will be presented below the figure.
72 Even though the interaction was not significant, the pairwise comparisons indicated that the vowels produced in closed syllables were always significantly closer to the centroid than those produced in open syllables. The p-values are as follows: /a/-- p = .034; /e/ -- p = .008; /i/-- p = .004; /o/-- p = .026; /u/-- p = .001.
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Figure 4-11. Vowel duration by syllable type. Values for all speakers averaged across stress and task.
The main effect revealed that averaged across all vowels, stress types, and tasks,
the vowels produced in closed syllables were significantly longer than those produced in
open syllables (closed syllables = 71 milliseconds, open syllables = 68 milliseconds).
The interaction between vowel and syllable type indicated that the effect of syllable type
on duration depended upon the vowel. The pairwise comparisons of this interaction
revealed that only the front vowels /e/ and /i/ exhibited significant differences in length
based on syllable type. The /e/ produced in closed syllables was significantly longer (72
milliseconds) than the /e/ produced in open syllables (66 milliseconds, p = .005). The
same pattern emerged for /i/, in which longer duration was observed in closed syllables
(66 milliseconds) than in open syllables (57 milliseconds, p < .001). No other vowels
exhibited significant differences with respect to syllable type.
The fact that vowels produced in closed syllables were longer than those in open
syllables led to the question of whether the following consonant could potentially
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Duration in ms
Vowel duration by syllable type
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influence vowel length. In order to test for this effect, the Mixed Linear Model on
duration was re-run including two additional variables: the voicing characteristics of the
following consonant (voiced or voiceless) and the manner of articulation of the following
consonant (stop, fricative, approximant, affricate, lateral, rhotic, and nasal). The results
of this additional analysis revealed a significant main effect of voicing (F(1, 3219.53) =
21.792, p < .001) and a significant main effect of manner (F(6, 3219.40) = 16.26, p <
.001). Pairwise comparisons of the main effect of voicing indicated that overall, vowels
that were followed by voiced consonants were significantly longer (77.29 milliseconds)
than those that were followed by voiceless consonants (60.23 milliseconds). The main
effect of manner of the following consonant indicated that the length of the vowel varied
significantly based on the manner in which the following consonant was produced.
Figure 4-12 provides a general picture of how vowel duration varied according to the
following consonantal context.
Figure 4-12. Average vowel duration based on the manner of the following consonant.
0 10 20 30 40 50 60 70 80 90
fricative
affricate
occlusive
approximant
rhotic
lateral
nasal
Duration in milliseconds Vowel duration by following consonant
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Vowels followed by fricatives were the longest (78.64 milliseconds) and those
preceding nasals were found to be the shortest (59.83 milliseconds).73 Because of the
unequal distribution of vowels in each of these categories, an in-depth discussion of
which consonants resulted in significantly longer vowel duration and pairwise
comparisons of this effect will not be discussed further.
The previous section discussed the effects of syllable type on HS vowel
production. There were no overall effects of syllable type on F1, indicating that syllable
structure did not have a significant effect on vowel height. An analysis of the effect of
syllable type on F2, however, did reveal several interesting effects. The significant
interaction between vowel and syllable type along the F2 dimension showed that vowels
in closed syllables had a slight tendency to be produced towards the center of the vowel
space. This difference was only found for the point vowels /i,a,u/, however, and not for
the mid vowels /e/ and /o/ which in the traditional Hispanic literature have typically been
argued to exhibit differences in F2 based on syllable type. The analysis of the Euclidean
distance measures revealed that vowels produced in closed syllables were closer to the
centroid than those produced in open syllables. Thus, the dispersion of vowels was
greater for vowels in open syllables and lesser for those in closed syllables. Syllable type
was also found to have an effect on vowel duration. Overall, vowels produced in closed
syllables were longer than those in open syllables, but this distinction was only
statistically significant for the front vowels /e/ and /i/.
73 Only one of the three tasks was somewhat balanced for preceding and following consonantal contexts due to the original goal of this research, and for this reason there were not an equal number of the five Spanish vowels in the context of each of the manners of articulation represented. In addition, many of the vowels in closed syllable contexts were in contact with /s/, which may explain why vowels produced in closed syllables were longer in duration than those produced open syllables, thus driving the vowel by syllable type interaction. These aspects of this investigation will be discussed in greater detail in chapter 5.
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4.1.1.4 Task
The final within-subjects variable included in the analysis is task, or speech style.
As mentioned in chapter 3, the participants completed three different activities which
elicited different speech styles: a narrative retelling task which represents the
spontaneous speech, a picture information task which represents semi-spontaneous
speech, and a carrier phrase task which represents controlled speech. For ease of
reference throughout this section and the rest of the chapter, the narrative retelling task
(spontaneous) will be referred to as the “NRT,” the picture identification task (semi-
spontaneous speech) as the “PIT,” and the carrier phrase task (controlled speech) as the
“CPT.” Prior to discussing the statistical results, the formant values and Euclidean
distances of each of the HS vowels are presented in Table 4-9.
Table 4-9
Formant values and Euclidean distance measures of HS vowels produced in all three tasks
Vowel Task F1 (Hz) F2 (Hz) Euclidean distance (Hz)
NRT 396.01bc 2141.73bc 509.79bc /i/ PIT 367.07ac 2205.96ac 568.44ac
CPT 341.99ab 2273.71ab 642.29ab
NRT 527.01bc 1803.16c 213.73c /e/ PIT 489.49b 1830.22c 216.17c
CPT 480.93a 2045.80ab 400.30ab
NRT 663.11bc 1556.31c 207.43c /a/ PIT 679.00ac 1533.09 230.06c
CPT 721.33ab 1499.27a 281.04ab
NRT 550.19bc 1204.97c 452.28c /o/ PIT 528.75b 1173.00c 479.39c
CPT 533.41a 1120.12ab 537.02ab
NRT 446.75bc 1208.27 455.15 /u/ PIT 417.81ac 1250.79c 428.05c
CPT 397.38ab 1167.46b 503.24b Note. The “a” denotes a significant difference from the NRT, the “b” from the PIT, and the “c” from the CPT.
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The F1 and F2 values for each vowel in each of the three tasks are represented
graphically in Figure 4-13. The solid line represents the vowel space in the NRT. The
dotted line represents the semi-spontaneous speech from the PIT. The dashed line
represents the controlled speech that was obtained in the CPT. As can be observed in the
figure, the controlled speech task occupies the greatest area of the acoustic space and
results in the most peripheral vowel productions. The NRT and PIT are more centralized
and pattern similarly to one another. The distribution of vowels based on speech style
and the statistical analyses will be described in greater detail below the figure.
Figure 4-13. Overall vowel space based on task (speech style). Values for all speakers averaged across stress and syllable type. NRT = narrative, PIT = picture identification, CPT = carrier phrase.
The Mixed Linear Model conducted with F1 as the dependent variable revealed a
significant main effect of task (F(2, 3254.38) = 25.24, p < .001) and a significant vowel
by task interaction (F(8, 3254.14) = 25.85, p < .001). The main effect of task indicated
that across all vowels, stress types, and syllable types, the vowels produced in the NRT
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(spontaneous speech) exhibited higher F1 values than vowels produced in the other two
tasks. The average F1 value in the NRT was 516.61 Hz, while in the PIT it was 496.42
Hz, and in the CPT 495.00 Hz. Pairwise comparisons of this main effect indicated that
the F1 values in the NRT were significantly higher than those in the PIT and CPT (p <
.001), but the F1 values in the PIT and CPT did not differ significantly from one another
(p = 1.00).
The vowel by task interaction for F1 indicated that the height of some of the HS
vowels differed according to the speech style in which they were produced. The F1 value
of /a/ was significantly lower in the NRT (663.10 Hz) than in the PIT (679.00 Hz, p =
.002), and the F1 of /a/ in the PIT was significantly lower than in the CPT (721.33 Hz, p
< .001). The height differences observed between the NRT and CPT were also
significant (p < .001). Thus, the /a/ was produced higher in the vowel space as the speech
became more spontaneous. The opposite pattern was observed for the high vowels: the
tokens of /i/ and /u/ produced in the NRT exhibited the highest F1 values and in the CPT
the lowest F1 values. For /i/, the F1 of vowels produced in the NRT (396.01 Hz) was
significantly higher than the F1 of vowels in the PIT (367.06 Hz), which was
significantly higher than the F1 of /i/ produced in the CPT (341.99 Hz). The difference
between the NRT and the two other tasks was significant at the level of p < .001, and the
difference between the PIT and CPT was significant at the level of p = .002. The same
pattern was observed for /u/, in which the vowels in the NRT had the highest F1 values
(446.75 Hz), followed by the PIT (417.81 Hz), and finally the CPT (397.38 Hz). The
differences reported for /u/ were significant on all levels, such that the F1 values in the
NRT differed significantly from the PIT (p = .014) and the CPT (p < .001), and the
174
values in the PIT and CPT also differed from one another (p = .009). The high vowels
thus exhibited the opposite behavior of /a/: the F1 values of /i/ and /u/ increased as
speech became more spontaneous, resulting in their movement downward in the acoustic
space.
The effect of task on the mid vowels was slightly different in that neither /e/ nor
/o/ showed significant differences between the NRT and the CPT. For /e/, the vowels
produced in the NRT had significantly higher F1 values (527.00 Hz) and were thus
produced lower in the vowel space than those in the PIT (489.49 Hz) and the CPT
(480.92 Hz). The difference in the F1 values of /e/ between the NRT and PIT/CPT was
significant at the level of p < .001. A similar pattern was revealed for the mid vowel /o/.
The F1 of /o/ produced in the NRT (550.18 Hz) was significantly higher than that
observed in the PIT (528.74 Hz) and the CPT (533.40 Hz), but the latter two tasks did not
differ significantly from each other (NRT from PIT, p = .002; NRT from CPT, p = .021;
PIT from CPT, p = 1.00). As with the high vowels, as the spontaneity of the speech
increased, so did the F1 value of the vowel. Thus, the mid vowels were produced the
lowest in the vowel space in the narrative retelling task, and higher in the picture
information and carrier phrase tasks.
The statistical analysis with F2 as the dependent variable also revealed robust
effects of speech style (again, see Figure 4-13). The Mixed Linear model revealed a
significant main effect of task (F(2, 3254.55) = 6.37, p = .002) as well as a significant
vowel by task interaction (F(8, 3254.21) = 23.711, p < .001) for F2. An examination of
the main effect via pairwise comparisons revealed that overall, the vowels produced in
the CPT had the highest F2 values (1621.27 Hz). The F2 in the CPT was found to be
175
significantly higher (i.e., farther front) than the F2 values of vowels produced in the NRT
(1582.88 Hz, p = .001) and in the PIT (1598.61 Hz, p = .044). The overall differences in
backness between the NRT and PIT were not significantly different from one another (p
= .283).
The significant interaction between vowel and task on the F2 dimension indicated
that some vowels exhibited distinct degrees of backness in different tasks. A closer
examination of this interaction via pairwise comparisons revealed that generally
speaking, the F2 values produced in the CPT were the most peripheral in the vowel space
and tended to differ significantly from those produced in the NRT. For the low vowel /a/,
the F2 produced in the NRT was significantly higher (1546.31 Hz) than the F2 of vowels
produced in the CPT (1499.27 Hz, p = .009). In the most spontaneous speech task, then,
the /a/ was produced farther front than when it was produced in the most controlled
speech style. The front vowel /i/ exhibited the most extreme (i.e., farthest front) F2 value
in the CPT (2273.70 Hz). This F2 value differed significantly from the F2 of /i/ in the
PIT (2205.95 Hz, p = .006) and from the NRT (2141.73 Hz, p < .000). The F2 values of
/i/ in the NRT and PIT also differed significantly from one another at the level of p =
.006. The mid front vowel /e/ also exhibited the most extreme F2 values in the CPT
(2045.80 Hz), which differed significantly from the F2 values produced in the PIT
(1830.15 Hz, p < .001) and NRT (1803.15 Hz, p < .001). The F2 values of /e/ in the NRT
and PIT did not differ significantly from one another (p = .221). Thus, as the speech style
became more controlled, /e/ and /i/ were produced with an increasingly more fronted
articulation.
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The back vowels showed the same pattern and tendency for more peripheral (i.e.,
lower) F2 values in the CPT, but in the opposite direction of the front vowels. For /o/,
the vowels produced in the CPT had the lowest F2 value (1120.12 Hz), and this was
significantly lower than the F2 in the PIT (1172.99 Hz, p = .019) and the NRT (1204.97
Hz, p < .001). There was no significant difference between the F2 values in the NRT and
PIT, however. Finally, /u/ only exhibited significant differences between the F2 values in
the PIT and CPT (PIT = 1250.79 Hz, CPT = 1167.46 Hz, p < .001). The /u/ produced in
the CPT had the lowest F2 value, thus resulting in this vowel being produced the furthest
back in the vowel space in the most controlled speech task. Based on these results, it can
be concluded that as the speech style became more controlled, the back vowels were
produced farther back in the vowel space.
An additional analysis of the effect of speech style on vowel production indicated
that the Euclidean distance of HS vowels from the center of the vowel space differs as a
consequence of speech style. Figure 4-14 illustrates the relative location of the five
Spanish vowels to the centroid, and how their positions varied in the different speech
styles. Refer to Table 4-9 for the actual Euclidean distance values.
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Figure 4-14. Vowel dispersion based on task (speech style). Values for all speakers averaged across stress and syllable type.
The Mixed Linear Model conducted with Euclidean distance as the dependent
variable revealed a significant main effect of task (F(2, 3254.73) = 89.78, p < .001) and a
significant vowel by task interaction (F(8, 3254.26) = 6.16, p <. 001). The main effect of
task indicated that vowels were dispersed differently throughout the acoustic space
according to speech style. The pairwise comparisons of this main effect revealed that the
vowels produced in the CPT, the most controlled speech style, were significantly farther
from the centroid than the vowels produced in the other two tasks. The average
Euclidean distance of vowels produced in the CPT was 472.77 Hz, which was
significantly longer (p < .001) than those produced in the PIT (384.42 Hz) and the NRT
(367.67 Hz). Although the average Euclidean distance of vowels produced in the PIT
was greater than that of NRT, this difference was not statistically significant (p = .083).
A closer examination of the vowel by task interaction revealed that the same
pattern described previously for the main effect was observed for all other vowels except
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F2 Hz HS vowel dispersion by task
NRT PIT CPT centroid
178
for /u/. For the low vowel /a/, the greatest distance from the centroid was observed in the
CPT (281.04 Hz), which was significantly greater than the distance in the PIT (230.05, p
= .002), and also significantly greater than the distance of vowels in NRT (207.42 Hz, p <
.001). The mid vowel /e/ was dispersed farthest from the centroid in the CPT (400.29
Hz), and this was significantly greater than the distance calculated in the PIT (216.17 Hz,
p < .001) and NRT (213.73 Hz, p < .001). The front vowel /i/ had the greatest degree of
dispersion overall, which was most apparent in the CPT (642.29 Hz). This distance was
significantly greater than those calculated in the NRT (509.78 Hz) and the PIT (568.43
Hz). Both comparisons with the CPT were significant at the level of p < .001. Finally,
/o/ exhibited the same decreasing pattern, with the longest Euclidean distance observed in
the CPT (537.01 Hz). Significantly closer to the centroid was the /o/ produced in the PIT
(479.39 Hz, p = .001), followed by the /o/ produced in the NRT (452.28 Hz, p < .001).
For the high back vowel /u/, the Euclidean distance of the vowels produced in the CPT
(503.23 Hz) was significantly greater than that of the PIT (428.04 Hz, p < .001), but not
when compared to the NRT (455.15 Hz, p = 2.10). The Euclidean distance of vowels
produced in the NRT and PIT were not significantly different for any of the five Spanish
vowels except for /i/, indicating that these two speech styles were characterized by
similar rates of dispersion from the centroid.
The duration of some HS vowels also differed statistically according to speech
style. The average vowel duration in milliseconds produced in each of the three speech
tasks are presented in Table 4-10.
179
Table 4-10
Vowel duration in each speech style
Vowel NRT PIT CPT
/i/ 60.73 61.43 62.86 /e/ 69.71 67.34 69.34 /a/ 72.44* 82.74 83.64 /o/ 60.12* 74.10 74.94 /u/ 63.01 68.07 66.41
Note. The “*” indicate that the duration of /a/ and /o/ in the NRT was significantly shorter than the duration in the PIT and CPT, but that the latter two did not differ significantly.
Figure 4-15 graphically represents the breakdown of vowel duration by each
speech style. The dark gray bars represent the NRT, the light gray bars the PIT, and the
black bars represent the CPT. As can be observed in the figure, the black bars have a
tendency to extend farthest to the right, indicating the longest duration, while the dark
gray bars are the shortest, indicating shorter duration. The light gray bars tend to have
intermediate values, although they are similar in length to the black bars. The statistical
analysis of duration will be discussed below the figure.
180
Figure 4-15. Vowel duration based on task (speech style). Values for all speakers averaged across stress and syllable type.
The statistical analysis of vowel duration revealed a significant main effect of task
(F(2, 3254.76) = 13.39, p < .001), as well as a significant vowel by task interaction (F(8,
3254.28) = 5.95, p < .001). The main effect of task indicated that collapsed across all
vowels, stress types, and syllable types, the vowels produced in the narrative retelling
task were significantly shorter than those produced in the other two tasks. The average
vowel duration in the NRT was 65.20 milliseconds. Pairwise comparisons of this main
effect indicated that the vowels produced in the NRT were significantly shorter than
vowels produced in the PIT (70.74 milliseconds) and the CPT (71.64 milliseconds).
These differences were significant at the level of p < .001. Although the vowels
produced in the CPT were the longest overall, they were not significantly longer than
those produced in the PIT.
The vowel by task interaction indicated that differences in duration based on
speech style were only significant for certain vowels. A closer examination of the
0 10 20 30 40 50 60 70 80 90
/i/
/e/
/a/
/o/
/u/
Duration in ms
Vowel duration in three speech tasks
NRT
PIT
CPT
181
interaction via pairwise comparisons revealed that only /a/ and /o/ differed significantly
with respect to duration. For /a/, the average vowel duration produced in the NRT (72.44
milliseconds) was significantly shorter than the average duration of /a/ in the PIT (82.74
milliseconds) and the CPT (83.64 milliseconds, p < .001 for all comparisons). There was
no statistically significant difference between the average duration of /a/ in the PIT and in
the CPT. The same pattern was observed for the back vowel /o/. The shortest duration
was observed in the NRT (60.12 milliseconds), followed by the PIT (74.10 milliseconds)
and the CPT (75.94 milliseconds). For /o/, the differences in duration between the NRT
and PIT, as well as between the NRT and CPT, were significant at the level of p < .001.
As with /a/, the vowels in the CPT were not significantly longer than those produced in
the PIT.
To conclude, this section presented the results of the analyses on speech style.
This variable had significant and robust effects on all four of the dependent variables. In
terms of vowel quality, there was a connection between the spontaneity of speech and the
degree of centralization in terms of height and backness. The vowels produced in the
spontaneous and semi-spontaneous speech styles occupied a more centralized location
within the vowel space when compared to the vowels produced in the carrier phrase task.
This difference in dispersion was further supported by the analysis of Euclidean distance.
The vowels produced in the carrier phrase task, the most controlled speech style,
exhibited the greatest distance from the center of the vowel space. Speech style also had
an impact on vowel duration. Vowels were the shortest in duration in the spontaneous
speech task and the longest in the controlled speech task, but the differences were only
statistically significant for /a/ and /o/. Taken together, the results of the analyses of
182
speech style indicate that vowels are produced differently in terms of both quality and
quantity depending on the type of speech in which they occur.
4.1.2 Complex interactions
In addition to the main effects and simple interactions described in the previous
four sections, two three-way interactions were included in the model in order to address
the effect of stress and syllable type within the different speech styles. The goal of this
section is to discuss how stress and syllable type effects manifested themselves within the
different speech styles, and how they impacted each of the dependent variables.
4.1.2.1 The interaction between vowel, task, and stress
The three-way interaction between vowel, task, and stress examined the
relationship between lexical stress and speech style for each of the five Spanish vowels.
This interaction was found to be significant for F1 (F(10, 3254.17) = 2.6, p = .004), F2
(F(10, 3254.26) = 13.86, p < .001), and Euclidean distance (F(10, 3254.26) = 14.74, p <
.001). These findings indicate that the effect of stress on each vowel depended upon the
task in which the vowel was produced. Prior to discussing the statistical results, the mean
F1, F2, and Euclidean distance values in Hertz of each vowel in each task are presented
Table 4-11. Vowel plots for each of the tasks will be presented throughout this section in
order to illustrate the statistical effects described in the text.
183
Forman
t values
and Eu
clidean
distan
ce meas
ures of
tonic a
nd aton
ic HS vo
wels pr
oduced
in each
speech
style
NRT
PITCP
T
Vowel
Stress
F1 (Hz
)F2
(Hz)
Euclide
an dist
ance (H
z)F1
(Hz)
F2 (Hz
)Euc
lidean
distanc
e (Hz)
F1 (Hz
)F2
(Hz)
Euclide
an dist
ance (H
z)/i/
atonic
414.49*
2021.05
*400
.60*362
.94216
7.67*
531.99*
351.53
2148.55
*518
.21*toni
c377
.53*226
2.41*
618.97*
371.19
2244.25
*604
.88*332
.45239
8.87*
766.37*
/e/aton
ic498
.32*170
7.00*
159.30*
459.34*
1765.84
*168
.62*437
.89*214
4.84*
502.74*
tonic
555.69*
1899.32
*268
.17*519
.65*189
4.61*
263.72*
523.96*
1946.77
*297
.85*/a/
atonic
627.87*
1587.49
*163
.60*642
.93*152
4.73204
.56*672
.68*146
1.57*
275.23
tonic
698.35*
1525.13
*251
.25*715
.07*154
1.46255
.56*769
.98*153
6.98*
286.85
/o/aton
ic528
.84*123
1.97*
419.17*
507.88*
1221.94
*429
.83*516
.84*117
9.10*
472.61*
tonic
571.54*
1177.98
*485
.40*549
.62*112
4.06*
528.96*
549.97*
1061.15
*601
.42*/u/
atonic
450.64
1215.37
452.00
418.96
1337.27
*352
.80*391
.66121
3.99*
460.18*
tonic
442.86
1201.16
458.30
416.66
1164.31
*503
.29*403
.11112
0.93*
546.30*
Note.
Asteris
ks deno
te signi
ficant d
ifferenc
es betw
een ton
ic and a
tonic fo
rmant v
alues an
d Eucli
dean di
stance m
easures
.
Tabl
e 4-
11
184
In spontaneous speech (the NRT), all vowels showed significant height
differences based on stress except for /u/. The differences in vowel quality in the NRT
are presented in Figure 4-16. The solid line represents the overall space of the tonic
vowels produced by all speakers, and the dashed line represents the atonic productions.
Figure 4-16. Tonic and atonic vowel space in spontaneous speech (NRT).
The pairwise comparisons of this interaction along the F1 dimension indicated
that the non-high vowels /a/, /e/, and /o/ exhibited significantly lower F1 values (i.e.,
were higher vowels) when unstressed (atonic) as compared to when they were stressed
(tonic). Thus, the atonic non-high vowels were produced higher in the acoustic space
than their tonic counterparts. The tonic/atonic comparisons for /a/, /e/, and /o/ were
significant with p-values < .001. In contrast, the high vowel /i/ exhibited significantly
higher F1 values in this task when it was atonic (p < .001). Atonic productions of /i/
were therefore situated lower in the acoustic space than the tonic productions.
300
400
500
600
700
800
90011001300150017001900210023002500
F1 H
z
F2 Hz Stress effects in the NRT
tonic atonic
185
Along the F2 dimension, all vowels except for /u/ showed significant stress
differences. The atonic productions of /a/ had higher F2 values than the tonic
productions, resulting in the atonic vowels being articulated further front in the vowel
space (p = .001). Likewise, the same pattern was observed with /o/. The atonic
productions of /o/ had significantly higher F2 values, resulting in a more fronted
production (p = .037). The front vowels /i/ and /e/ exhibited significantly lower F2
values when produced in atonic syllables when compared to tonic syllables (for /e/, p =
.022; for /i/, p < .001). The effects on F1 and F2 resulted in the atonic vowels occupying
a more centralized portion of the acoustic space when compared to the tonic productions.
As can be observed in Figure 4-16, the atonic vowel space falls within the tonic vowel
space.
The analysis of the Euclidean distance measure of vowels in the NRT indicated
that the atonic productions of /i/, /e/, /a/, and /o/ were all significantly closer to the
centroid than the tonic productions of these vowels. This difference was significant at the
level of p < .001 for /i/, /e/, and /a/, and at the level of p = .002 for /o/. The relationship
between these vowels and the center of the vowel space are presented in the Figure 4-17.
The center of the vowel space is marked with an “x” and helps conceptualize the
proximity of the vowels to the center of the space.
186
Figure 4-17. Tonic and atonic dispersion in spontaneous speech (NRT).
In the semi-spontaneous speech task (the PIT) a similar pattern emerged. The
stress effects in this task are represented in Figure 4-18. As with the previous figures, the
dashed line represents the atonic vowel productions and the solid line denotes the tonic
vowel productions.
Figure 4-18. Tonic and atonic vowel space in semi-spontaneous speech (PIT).
300
400
500
600
700
800
90011001300150017001900210023002500
F1 H
z
F2 Hz Tonic and atonic dispersion in the NRT
tonic atonic centroid
300
400
500
600
700
800
90011001300150017001900210023002500
F1 H
z F2 Hz
Stress effects in the PIT
tonic atonic
187
In the PIT, the non-high vowels /a/, /e/, and /o/ exhibited significant differences in
vowel height based on stress context. The pairwise comparisons of this interaction
revealed that all three of these vowels were produced with significantly lower F1 values
when atonic as compared to tonic (for all comparisons, p < .001). Thus, the non-high
vowels moved up towards the center of the vowel space when they were unstressed.
Along the F2 dimension, all vowels except for /a/ showed significant movement towards
the middle of the vowel space when they were produced in atonic syllables. The front
vowels /i/ and /e/ exhibited significantly lower F2 values in atonic syllables and were thus
articulated farther back in the vowel space when compared to their tonic counterparts (for
/i/ tonic = 2244.24 Hz, atonic = 2167.67 Hz, p = .002; for /e/, tonic = 1894.61 Hz, atonic
= 1706.99 Hz, p < .001). The back vowels exhibited the same movement towards the
center of the vowel space when produced in atonic syllables. The atonic values of /o/ and
/u/ were 1221.94 Hz and 1337.27 Hz, respectively, which were significantly higher than
those of tonic /o/ (1124.05 Hz) and tonic /u/ (1164.30 Hz). The tonic and atonic
comparisons between these two vowels were both statistically significant (p < .001 for
both /o/ and /u/).
The Euclidean distance measures in the PIT were also found to differ significantly
based on stress context. The pairwise comparisons of this interaction revealed that all
atonic vowels exhibited significantly shorter Euclidean distance measures when
compared to their tonic counterparts. For all vowels, the comparisons between tonic and
atonic Euclidean distance were significant with a value of p < .001. The tonic and atonic
vowel space in the PIT is represented in Figure 4-19. The “x” marks the position of the
188
center of the vowel space and helps conceptualize the relationship of each vowel to this
centroid.
Figure 4-19. Tonic and atonic dispersion in semi-spontaneous speech (PIT).
Finally, several vowels showed stress effects in the controlled speech task (the
CPT). Figure 4-20 represents the tonic and atonic vowel productions in the CPT, with
the solid lines representing the tonic productions and the dashed lines the atonic vowel
productions.
300
400
500
600
700
800
90011001300150017001900210023002500
F1 H
z
F2 Hz Stress effects in the PIT
tonic atonic centroid
189
Figure 4-20. Tonic and atonic vowel space in controlled speech (CPT).
The pairwise comparisons of this interaction revealed that atonic productions of
/a/, /e/, and /o/ exhibited significantly lower F1 values in the CPT. This finding indicates
that the non-high vowels were situated higher in the vowel space when they were atonic
as compared to when they were tonic (p < .001 for /a/ and /e/; p = .002 for /o/). In terms
of vowel backness, the atonic productions of /a/ exhibited a significantly lower F2 vowels
when compared to tonic productions, and were therefore produced farther back in the
vowel space (p = .022). The same pattern was observed for atonic /i/, which had a
significantly lower F2 value when produced in atonic syllables as compared to tonic
syllables (p < .001). Thus, both /a/ and /i/ were produced farther back in the vowel space
when they were unstressed as compared to when they were stressed. The same pattern,
but in the opposite direction, was shown again for the back vowels /o/ and /u/. Both of
these vowels were characterized by significantly higher F2 values in atonic syllables as
compared to tonic syllables, resulting in the atonic productions of these vowels moving
300
400
500
600
700
800
90011001300150017001900210023002500
F1 H
z
F2 Hz Stress effects in the CPT
tonic atonic
190
farther front, or more towards the center, of the vowel space. These differences were
statistically significant for both vowels (for /o/, p < .001; for /u/, p = .002). Interestingly,
in this task only, the atonic /e/ had a higher F2 value than tonic /e/ and was thus situated
farther front in the vowel space (p < .001). This unexpected result is explained in greater
detail later in this chapter.
The analysis of Euclidean distance calculated for the vowels produced in the CPT
revealed that even in the controlled speech task (CPT), stress had a significant effect on
the proximity of each vowel to the center of the space. The relationship between the
vowels produced in the CPT and the centroid are illustrated in Figure 4-21.
Figure 4-21. Tonic and atonic vowel dispersion in controlled speech (CPT).
The pairwise comparisons of the interaction between vowel, stress, and task in the
CPT revealed that atonic /i/, /o/, and /u/ had significantly shorter Euclidean distances
when compared to their tonic counterparts (all comparisons p < .001). The front vowel
/e/, on the other hand, had a significantly longer Euclidean distance when it was atonic as
300
400
500
600
700
800
90011001300150017001900210023002500
F1 H
z
F2 Hz Tonic and atonic dispersion in the CPT
tonic atonic centroid
191
compared to when it was tonic, indicating that the atonic vowel was actually farther from
the centroid than the tonic vowel (p < .001). This finding is directly related to the F2
value calculated for atonic /e/ in the CPT. As reported earlier, the F2 of the atonic /e/ was
higher than the tonic vowel, resulting in it occupying a more fronted position within the
vowel space. When entered into the formula to calculate the distance from the centroid,
the larger F2 value thus resulted in a larger Euclidean distance.
The difference in vowel backness and Euclidean distance may be a consequence
of the lexical items and consonantal context in which atonic /e/ occurred in the CPT. The
carrier phrase task was more heavily weighted toward examining tonic vowels in open
syllables. The atonic /e/ vowels in this task were obtained from the words “eclipse”
(eclipse) and “equipo” (team). Both of these words contain word-initial /e/ in the context
of a voiceless velar consonant. The word “eclipse” is also a cognate, and some speakers
Anglicized their pronunciation, thus resulting in the elimination of this token from the
analysis. In the English pronunciation, the initial vowel is a high front /i/, and not the /e/
of Spanish. The combination of “equipo” and “eclipse” both containing an /e/ embedded
in the same consonantal context, and the possibility of producing the high front /i/ instead
of /e/ in “eclipse” could have potentially skewed the results. Thus, the findings with
respect to F2 and Euclidean distance for this vowel in this task should be interpreted with
caution.
An examination of the Type III effects in the analysis of duration revealed that the
three-way interaction between vowel, task, and stress was not significant for duration.
This result occurred because in all tasks and all speech styles, atonic vowels were always
significantly shorter than tonic vowels. The tendency for atonic vowels to be produced
192
with shorter duration (in milliseconds) is represented in Table 4-12, and represented
graphically in Figure 4-22.
Table 4-12
Tonic and atonic duration in three speech tasks Vowel Stress NRT PIT CPT
/i/ atonic 50.93 55.16 55.25
tonic 70.54 67.69 70.47
/e/ atonic 54.72 53.72 53.10
tonic 84.71 80.97 85.57
/a/ atonic 58.33 68.51 68.60
tonic 86.55 96.97 98.68
/o/ atonic 49.28 57.45 62.40
tonic 70.96 90.75 89.48
/u/ atonic 53.58 51.75 52.35
tonic 72.43 84.40 80.47
Note. All atonic vowels were significantly shorter than their tonic counterparts.
The interaction did not emerge significant because the effect of lexical stress on
duration does not depend on the task: it was consistent in all tasks and for all vowels.
The effects of lexical stress were confirmed by the pairwise comparisons of the
interactions, and were significant for all vowels in all tasks at the level of p < .001 except
for /i/ in the CPT (p = .001). The consistency of this pattern is depicted in Figure 4-22,
which represents the average vowel duration of tonic and atonic vowels in each of the
three speech styles. The gray bars represent atonic productions and the black bars tonic
productions. As shown below, the gray bars representing atonic vowel duration are
consistently shorter than the black bars, regardless of the speech style in which they were
produced.
193
Figure 4-22. Tonic and atonic duration in each of the three speech styles, averaged across syllable type.
To summarize the main results of this section, the significant interaction between
vowel, task, and stress indicated the interplay between these three factors. Overall, atonic
vowels in all speech styles exhibited significantly lower F1 values, resulting in vowels
that were produced higher in the vowel space in all three tasks (see Figure 4-16, Figure
4-18, and Figure 4-20). This raising of unstressed vowels, and lowering of the high
vowel /i/, seemed to be slightly more prevalent in the spontaneous speech task (NRT).
With respect to F2, nearly all atonic vowels in all speech styles exhibited formant values
that were more centralized, thus lower F2 values for the front vowels and higher F2
values for the back vowels. The low vowel /a/ showed some variation with respect to
0 10 20 30 40 50 60 70 80 90 100
atonictonic
atonictonic
atonictonic
atonictonic
atonictonic
atonictonic
atonictonic
atonictonic
atonictonic
atonictonic
atonictonic
atonictonic
atonictonic
atonictonic
atonictonic
NR
TPI
TCP
TN
RT
PIT
CPT
NR
TPI
TCP
TN
RT
PIT
CPT
NR
TPI
TCP
T
/i//e
//a
//o
//u
/
Duration in ms Tonic and atonic vowel duration in three tasks
194
speech style, and /e/ exhibited an unanticipated pattern in the CPT which may be the
result of the lexical items elicited in that task. The overall tendency of atonic vowels to
centralize in all three tasks was further corroborated by the Euclidean distance measures
(see Figure 4-17, Figure 4-19, and Figure 4-21). With few exceptions, the atonic vowels
were characterized by significantly shorter Euclidean distances and were therefore closer
to the center of the vowel space than tonic vowels. Finally, although the interaction
between vowel, task, and stress was not significant for duration, a closer examination of
vowel duration revealed that across the board, atonic vowels were shorter than tonic
vowels (see Figure 4-22). The interaction was not significant for duration given the
consistency of the pattern and the fact that the shortening of atonic vowels did not depend
on the vowel or the task in which it was produced.
4.1.2.2 The interaction between vowel, task, and syllable type
The inclusion of the three-way interaction between vowel, task, and syllable type
allowed for closer examination of how syllable structure effects manifested themselves in
different speech styles. This vowel by task by syllable type interaction was significant
for F1 (F(10, 3254.10) = 6.70, p < . 001), F2 (F10, 3254.16) = 4.44, p < .001), Euclidean
distance, (F(10, 3254.19) = 4.08, p < .001), and duration (F(10, 3254.21) = 3.24, p <
.001). The significant interaction on all four of the dependent variables indicated the
interplay of vowel, task, and syllable type on vowel height, backness, distance from the
centroid, and duration. Unlike the three-way interaction between vowel, task, and stress,
however, the interactions involving syllable type were not as robust or consistent. The
vowel quality (i.e., F1 and F2) and Euclidean distance results will be presented separately
for each task, followed by analysis of duration in each task.
195
Prior to discussing the statistical results, Table 4-13 presents the average F1, F2,
and Euclidean distance measures in Hertz of each of the five Spanish vowels produced in
open and closed syllables. The table is divided according to speech task. Additional
figures illustrating the effects will be presented throughout the section.
196
Forman
t values
and Eu
clidean
distan
ce meas
ures of
HS vow
els pro
duced i
n close
d and op
en sylla
bles in t
hree sp
eech st
ylesNR
TPIT
CPT
Vowel
Syllable
type
F1F2
Euclide
an dist
ance
F1F2
Euclide
an dist
ance
F1F2
Euclide
an dist
ance
/i/clos
ed400
.54212
0.32478
.33*368
.18220
1.12565
.84340
.96224
6.01615
.76*ope
n391
.48216
3.14541
.24*365
.95221
0.80571
.03343
.02230
1.40668
.82*/e/
closed
532.49
1817.42
210.10
483.53
1795.75
*195
.35*476
.08202
2.25373
.28ope
n521
.52178
8.90217
.37495
.46186
4.70*
236.99*
485.77
2069.35
427.31
/a/clos
ed650
.57*158
3.09*
183.74*
686.51*
1518.61
239.76
735.19*
1547.93
*260
.04ope
n675
.65*152
9.54*
231.11*
671.49*
1547.57
220.36
707.48*
1450.62
*302
.04/o/
closed
569.15*
1243.41
*417
.68*525
.89117
8.67474
.47518
.87*112
1.63531
.98ope
n531
.23*116
6.53*
486.88*
531.61
1167.33
484.32
547.94*
1118.61
542.06
/u/clos
ed456
.66123
4.49414
.24428
.50*124
3.13438
.04394
.18122
9.48*
444.01*
open
436.84
1182.05
496.07
407.12*
1258.45
418.05
400.58
1105.43
*562
.46*Not
e. Aster
isks den
ote sign
ificant d
ifferenc
es betw
een vow
els pro
duced i
n close
d and o
pen syl
lables.
Tabl
e 4-
13
197
The distribution of vowels produced in open and closed syllables in the NRT is
presented in Figure 4-23. The solid lines represent the vowels produced in closed
syllables, and the dashed lines represent the distribution of vowels produced in open
syllables.
Figure 4-23. Vowel space based on syllable type in spontaneous speech (NRT).
As depicted in Figure 4-23, the vowels /a/, /o/, and to a lesser degree /i/, showed
significant quality (i.e., F1 and F2) differences and Euclidean distances in the NRT based
on the syllable type in which they were produced. Pairwise comparisons of this
interaction revealed that only /a/ and /o/ showed significant height differences in this task
based on syllable type. The /a/ was characterized by a lower F1 when it was produced in
a closed syllable, indicating that it was articulated higher in the vowel space (p < .001).
The opposite effect was observed for /o/. The F1 of /o/ produced in closed syllables was
significantly higher, indicating that the vowel was produced lower in the acoustic space
(p < .001). With respect to F2, only /a/ and /o/ exhibited significant differences in
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Syllable type effects in the NRT
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backness based on syllable type. For /a/, the closed syllables were characterized by
higher F2 values and were thus produced farther front in the vowel space when compared
to the vowels produced in open syllables (p = .006). The tokens of /o/ in closed syllables
also exhibited higher F2 values and were also more centralized when compared to vowels
in open syllables (p = .003).
In the NRT, only three vowels showed effects of syllable type on Euclidean
distance. The pairwise comparisons indicated that /a/, /i/, and /o/ produced in closed
syllables had significantly shorter Euclidean distance measures than their open
counterparts (for /a/, p = .003; for /o/, p = .001; for /i/, p = .017). Thus, the /a/, /i/, and /o/
produced in closed syllables were situated closer to the centroid than the same vowels
produced in open syllables. Figure 4-24 illustrates these distance effects.
Figure 4-24. Vowel dispersion by syllable type in spontaneous speech (NRT).
The analysis of the effect of syllable type in the PIT revealed few significant
results. The only vowels to exhibit significant differences in terms of height or backness
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Dispersion by syllable type in the NRT
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in this task were /e/, /a/, and /u/. These differences are illustrated in Figure 4-25, and will
be explained in greater detail below the figure.
Figure 4-25. Vowel space based on syllable type in semi-spontaneous speech (PIT).
The pairwise comparisons of the interaction between vowel, task, and syllable
type indicated that only /a/ and /u/ exhibited height differences as a consequence of
syllable structure in the PIT. Both the /a/ and the /u/ produced in closed syllables had
higher F1 values, meaning that they were produced lower in the vowel space, when
compared to their open counterparts (for /a/, p = .016; for /u/, p = .014). In terms of
vowel backness (F2), only /e/ showed significant effects of syllable type. The /e/
produced in closed syllables in this task were produced with significantly lower F2 values
and thus were situated farther back in the vowel space when compared to the /e/ produced
in open syllables (p = .001). Although the effects of syllable type on /a/ and /u/ appear
marginal in Figure 4-25, the effect on /e/ is quite clear.
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Syllable type effects in the PIT
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The /e/ was the only vowel to show a significant difference in Euclidean distance
based on syllable type. According to the pairwise comparisons, /e/ produced in closed
syllables was situated significantly closer to the centroid than the /e/ produced in open
syllables. Figure 4-26 presents the relationship between the vowels produced in the PIT
and their proximity to the center of the vowel space.
Figure 4-26. Vowel dispersion by syllable type in semi-spontaneous speech (PIT).
In the carrier phrase task (the CPT), which elicited the most controlled speech, all
vowels except for /e/ exhibit some kind of difference in either height or backness as a
consequence of syllable type. The effects of syllable type in the CPT are presented in
Figure 4-27.
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Dispersion by syllable type in the PIT
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Figure 4-27. Vowel space based on syllable type in controlled speech (CPT).
As with the NRT, only /a/ and /o/ exhibited significant height differences as a
result of syllable type. Interestingly, however, the effects observed in the CPT are the
opposite of those reported for the spontaneous speech style (NRT). The /a/ produced in
closed syllables had a significantly higher F1 than the /a/ produced in open syllables,
resulting in it occupying a lower position in the acoustic space (p = .005). For /o/, the F1
value in closed syllables was significantly lower than the F1 in open syllables, meaning
that the /o/ was produced higher in the acoustic space in closed syllables (p = .005). Only
two vowels were affected by syllable type on the F2 dimension. The low vowel /a/ was
produced with a higher F2 value in closed syllables than in open syllables (p = .001).
The same effect was observed for /u/ (p < .001), indicating that both the /a/ and the /u/
were produced farther front in the vowel space when they occurred in closed syllables as
compared to open syllables.
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Syllable type effects in the CPT
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The Euclidean distance measures of the vowels produced in the CPT were also
found to differ according to syllable type. The distribution of the vowels produced in
closed and open syllables in the CPT is illustrated in Figure 4-28.
Figure 4-28. Vowel dispersion by syllable type in controlled speech (CPT).
Pairwise comparisons of the interaction between vowel, task, and syllable type
indicated that only the high vowels exhibited significant differences in distance based on
syllable type. For both /i/ and /u/, the Euclidean distance measure was smaller for closed
syllables than for open syllables. In other words, in the controlled speech task, /i/ and /u/
produced in closed syllables were closer to the center of the vowel space than their open
counterparts. No other Euclidean distance measures were found to be significant in this
task.
With respect to vowel duration, the vowel by task by syllable type interaction was
also found to be significant (F(10, 3254.21) = 3.24, p < .001), indicating that the effects
of syllable type on length differed for certain vowels and in certain tasks. The length
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differences were only found to be significant for /e/, /i/, and /u/, but not in all speech
styles. Table 4-14 presents the average vowel duration in each task and in each syllable
type. Values are presented in milliseconds.
Table 4-14
Vowel duration by syllable type in three tasks Vowel Syllable
type NRT PIT CPT
/i/ closed 66.48* 69.99* 62.85 open 54.99* 52.86* 62.86
/e/ closed 74.38* 68.27 72.44 open 65.05* 66.42 66.24
/a/ closed 72.91 80.93 84.87 open 71.97 84.55 82.42
/o/ closed 61.25 77.49 74.81 open 58.99 70.71 77.07
/u/ closed 59.16 72.49* 62.48* open 66.86 63.65* 70.33*
Note. “*” denote a significant difference.
Pairwise comparisons of this interaction indicated that in the NRT, the /e/
produced in closed syllables was significantly longer than the /e/ produced in open
syllables (p = .001). The same effect was found for /i/ in the NRT and PIT, in which the
vowels in closed syllables were significantly longer than in open syllables (for the NRT,
p = .006; for the PIT, p < .001). The back vowel /u/ also exhibited differences in duration
according to syllable type in the PIT and the CPT. In the PIT, the vowels produced in
closed syllables were significantly longer than those produced in open syllables (p =
.009), but in the CPT, the vowels in closed syllables were significantly shorter than those
produced in open syllables (p = .040). Figure 4-29 represents the average vowel duration
by syllable type in each of the three tasks. The gray bars represent the duration in closed
syllables, and the black bars the duration of vowels in open syllables
204
Figure 4-29. Vowel duration in closed and open syllables in each task.
To summarize the findings presented in this section, the significant interaction
between vowel, task, and syllable type indicated that the effects of syllable type on HS
vowel quality and quantity varied according to the vowel and according to the speech
style. Differences in vowel quality and dispersion based on syllable type were present in
all three tasks, but none of the three speech styles seemed to show greater effects of
syllable structure than the others. The vowels /a/ and /o/ showed the greatest effects in
terms of vowel height. When comparing the spontaneous speech task (NRT) to the
carrier phrase task (CPT), however, the height of these vowels actually exhibited the
opposite pattern. In the NRT, the /a/ in closed syllables was produced higher than open
0 10 20 30 40 50 60 70 80 90
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TPI
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TN
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NR
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T
/i//e
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/
Duration in ms Vowel duration by syllable type in three tasks
205
syllables and the closed /o/ was produced lower than the /o/ in open syllables, but the
exact reverse occurred in the CPT. This interaction also revealed differences in backness
based on syllable structure. The general trend was for vowels in closed syllables to move
closer to the center of the vowel space, and this effect was most visible with the
pronunciation of /e/ in the PIT. When effects of Euclidean distance were observed, the
vowels produced in closed syllables were found to be closer to the centroid than those
produced in open syllables. Finally, syllable type effects were also observed for duration,
but only the vowels /i/, /e/, and /u/ were affected, and only in certain tasks. Generally,
these vowels were longer in duration when they occurred in closed syllables in the NRT
(spontaneous) and the PIT (semi-spontaneous). In the CPT the /u/ actually showed the
reverse pattern. Taken together, the results of this analysis indicated that the effects of
syllable type on vowel quality and quantity in different speech styles were not as
consistent as the effects of lexical stress. As few vowels showed effects and the effects
often differed according to the task, it can be concluded that speech style and syllable
type interact, but minimally and in variable fashion.
4.1.3 Summary of within-subjects effects
To summarize the findings presented in this section, HS Spanish vowels exhibit a
number of qualities that differ from traditional descriptions of monolingual Spanish
varieties. In terms of the overall organization and distribution of HS vowels, the analyses
revealed statistical differences in vowel height and backness. The high front vowel /i/
was found to be significantly higher than the back vowel /u/, and the front mid vowel /e/
was significantly higher than the back vowel /o/. The /a/ occupied the lowest position in
the acoustic space, and was significantly lower than all vowels. In terms of backness, the
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front vowels /i/ and /e/ differed significantly on the F2 dimension, with the /i/
significantly farther front than the /e/. This same distinction was not observed for the
back vowels /o/ and /u/, which statistically did not differ along the F2 dimension. The
central vowel /a/ was different from all other vowels in terms of F2.
The overall organization and dispersion of HS vowels, as measured by the
Euclidean distance from the center of the vowel space, revealed that this system is not as
symmetrical as previous descriptions suggest. Not all vowels were located at an equal
distance from the center, which differs from arguments that the Spanish vowel system
exhibits a high degree of symmetry. The low vowel /a/ was actually closest to the center
in Euclidean terms, followed by /e/, then /o/ and /u/, and finally /i/ with the largest
Euclidean distance.
The initial examination of duration indicated that the HS vowels exhibit intrinsic
vowel duration. The overall length of the vowels varied as a function of vowel height,
with the low vowel /a/ exhibiting the longest duration and the high vowels /i/ and /u/ the
shortest duration. This shortening of duration as vowel height increases has been
documented in other languages as well as in monolingual varieties of Spanish.
In contrast to what is typically argued for Spanish vowels, lexical stress had
significant effects on vowel quality, quantity, and dispersion. In terms of quality, atonic
vowels, and especially the non-high vowels, were articulated significantly higher in the
acoustic space in comparison to tonic vowels. In terms of backness, atonic vowels
exhibited more centralized F2 values (i.e., lower for the front vowels and higher for the
back vowels) when compared to their tonic counterparts. The tendency for centralization
in atonic syllables was confirmed based on the Euclidean distance measures calculated
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for each vowel in the two stress contexts. Overall, the atonic vowels were situated
significantly closer to the center of the vowel space than were tonic vowels, and this trend
was observed to some degree in all speech styles. Robust differences in vowel duration
were also reported. Collapsing across all syllable and task types, as well as within the
individual task types, atonic vowels were significantly shorter than tonic vowels.
The results of the analyses of syllable type were less transparent than those
reported for lexical stress. Although the Spanish mid vowels are typically argued to
exhibit allophonic variation along the F1 dimension based on syllable type, there is little
evidence to support this claim in the data. There was no significant main effect or simple
interaction for syllable type along the F1 dimension, indicating that overall, vowel height
was not affected by syllable type. When speech style was considered and examined via
the three-way interaction between vowel, task, and syllable type, however, /a/, /o/, and /u/
showed differences in height. Although the patterns that emerged were not consistent,
there was a slight tendency for vowels in closed syllables to be articulated higher in the
vowel space. Along the F2 dimension, only the point vowels showed significant
differences in backness. The /i/, /a/, and /u/ were all characterized by more centralized F2
values when they were produced in closed syllables as compared to open syllables. The
tendency for vowels in closed syllables to occupy a more centralized location was
observed in the different speech styles, and especially in spontaneous speech (NRT) and
controlled speech (CPT). The Euclidean distance measure painted a clearer picture of the
effects of syllable type on vowel quality. By taking into consideration both the F1 and F2
values, this measure showed that vowels produced in closed syllables tended to be closer
to the center of the vowel space than vowels produced in open syllables. Finally, the
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analyses of duration showed that vowels produced in closed syllables were overall longer
than those produced in open syllables. This finding was particularly relevant for the front
vowels /e/ and /i/. When speech style was added to the equation, these vowels were
generally longer in closed syllables in the NRT and the PIT, but the reverse was revealed
for the CPT, and more specifically for /u/.
Finally, the HS Spanish vowels exhibited differences in quality, duration, and
distribution based on speech style. These findings corroborate previous descriptions of
the effect of speech style on vowel production in monolingual and bilingual varieties of
Spanish. In terms of quality, the vowels produced in the spontaneous speech task (NRT)
and the semi-spontaneous speech task (PIT) occupied a more centralized location within
the vowel space. Thus, the vowels produced in these tasks exhibited F1 values that were
higher (except for the high vowels), lower F2 values for the front vowels, and higher F2
values for the back vowels. The vowels produced in the controlled speech task (CPT),
however, exhibited more extreme F1 and F2 values resulting in their situating themselves
on the periphery of the vowel space. These findings were further confirmed by the
Euclidean distance measures. Overall, the vowels produced in the NRT were situated
closest to the center of the vowel space, followed by the vowels produced in the PIT, and
finally the CPT. Duration also differed as a consequence of speech style. Averaged
across all stress and syllable types, the vowels produced in the NRT were significantly
shorter than those produced in the other two tasks. Vowel duration in the PIT was
generally shorter than that observed in the CPT, but the differences were not statistically
significant.
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Taken together, the results of the statistical analyses of the within-subjects
variables (i.e., lexical stress, syllable type, and speech style) revealed that the HS vowel
system is similar to descriptions of monolingual Spanish varieties in some ways but
differs in others. The overall distribution and positioning of the vowels within the space,
as well as the lack of symmetry, distinguishes the HS system from the traditional
descriptions of monolingual Spanish. The presence of intrinsic vowel duration is similar
to other Spanish vowel systems, although, as will be described and discussed in the
following chapter, the duration of HS vowel seems to be longer than values reported in
other studies. Although some dialects of Spanish, more specifically Mexican Spanish,
have been reported to exhibit reduction of atonic vowels, the general consensus in the
literature is that stress differences in Spanish tend to be minimal. The results described
previously in this section, however, present evidence for robust differences in vowel
pronunciation based on lexical stress. Syllable type effects in HS Spanish are less clear.
Although it was expected that the mid vowels would show differences in vowel height
and backness based on syllable type, there was no overall effect of syllable structure on
F1 and the effects on F2 were limited to the point vowels. Finally, HS vowels showed
the anticipated effects of speech style: vowels were more centralized in spontaneous
speech and more peripheral in controlled speech.
The following chapter will provide a more in-depth analysis and comparison of
the HS vowel system to other monolingual and bilingual systems. Before proceeding to
the discussion and conclusions, however, it is important to address how a different set of
variables, namely the social and individual variables, affected HS vowel production.
This topic will be discussed in section 4.2.
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4.2 Between-subjects variables
In addition to the within-subjects variables described in section 4.1, a series of
individual characteristics (i.e., between-subjects variables) were also included in the
model to address how each speaker’s language background and use, travel frequency,
formal grammatical knowledge, and course level were correlated with their vowel
production (see chapter 3, section 3.4.2). These between-subjects variables can be
divided into two larger groups, each necessitating a different type of statistical analysis:
categorical variables and continuous variables. The categorical social variables are
course level, travel frequency74, and gender.75 These variables were analyzed in much
the same way as the within-subjects variables via an examination of the estimated
marginal means. Participants were grouped into categories based on the course in which
they were currently enrolled, how frequently they traveled to their country of heritage,
and by their gender. The analyses then assessed how each group differed with respect to
F1, F2, duration, and Euclidean distance.
74 As a reminder, travel frequency was categorical. Participants were divided into three groups based on how often they reported traveling to the heritage country: frequently, infrequently, and almost never. 75 Although both male and female speakers participated in this study, no direct comparison will be made concerning gender and vowel pronunciation. The ratio of males to females (3:13) is too uneven for a meaningful analysis to be conducted. The variable of gender was, nonetheless, included in the analysis to remove some of the variance caused by gender differences. It is well-accepted that male and female speakers produce vowels differently as a consequence of physiology (Hillenbrand et al., 1996; Peterson & Barney, 1952; Rosner & Pickering, 1994). The statistical tests included in this analysis proved that this was the case. The analyses revealed a significant main effect of gender on F1 (F(1, 8.004) = 7.58, p = .025) and on Euclidean distance (F(1, 8.00) = 15.16, p = .005). These results indicated that, as expected, the overall F1 values for males were lower than for females. The significant effect of Euclidean distance indicated that female speakers showed greater degrees of vowel dispersion than males. These effects are due to the physiological differences between the genders, as females have the capacity to produce sounds at higher frequency ranges. For this reason, their F1 frequencies were higher (i.e. lower vowels) and their F2 frequencies were also higher (i.e. front vowels that were farther front). The combination of the higher F1 and F2 values resulted in a greater degree of dispersion for female speakers as compared to males. These are the basic findings of the analysis of gender, and no further discussion will be provided. Had an equal number of male and female participants completed this study, a direct comparison of male and female vowel production could have been conducted.
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In contrast, the continuous variables were analyzed using a different set of
statistical tests and comparisons because each speaker had their own numerical score and
was not placed into a larger group. These variables included grammar proficiency score,
Spanish use, and cultural sensitivity score. As these variables, as well as the dependent
variables, were both continuous, the model was not able to calculate estimated marginal
means like it could for the categorical within- and between-subjects factors. In order to
determine how the continuous independent variables affected the dependent variables, the
parameter estimates of fixed effects were used. The coefficients functioned much like
they do in a linear regression. The coefficient of the parameter estimate could be either
positive or negative, indicating a positive or negative relationship between the
independent factor(s) and the dependent variable. Thus, a negative coefficient indicated
that there was a negative correlation between the independent factor and the dependent
variable (i.e., as grammar score increased, F2 decreased), whereas a positive coefficient
indicated the reverse (i.e., as cultural sensitivity increased, F1 increased). The value of
the coefficient represented the steepness of the slope of the regression line. The larger
the number, the steeper the slope, and the larger the effect when compared to a slope of
zero.76 In the case of interactions between the vowels and a certain characteristic, the
interaction term was calculated by adding the parameter estimate of the individual vowel 76 It is important to address, however, that the vowel /u/ was always set to zero and served as the standard to which the other parameter estimates were compared. In some cases, however, the differences between the parameter estimate for a specific vowel as compared to the actual value of /u/ as observed in a separate portion of the parameter estimates table was greater than it was from zero. In certain cases, which will be explained in greater detail throughout this section as they apply, it is more meaningful to compare the largest parameter estimate to the smallest. This comparison not only indicates the direction of the effect (i.e. positive or negative correlation) but also the size of the effect. A parameter estimate of -10, for example, would indicate a greater (negative) effect than an estimate of +4. The comparison of these two values to each other, however, shows an even greater difference than comparing either of the values to zero. As will be explained later in this chapter, some of the significant interactions were driven based on the large differences between positive and negative parameter estimates.
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to the parameter estimate of the main effect. This procedure will be described in greater
detail later on in this chapter as it applies to the results. All information pertaining to
each participant’s group, travel frequency, and scores for grammar proficiency, cultural
sensitivity, and Spanish use are presented in Table 4-15.
Table 4-15
Information pertaining to individual characteristics
Participant ID Gender Course level
Travel group
Score on grammar proficiency test
Score on cultural sensitivity questionnaire
Score on Spanish use survey
Speaker 1F F 1 1 20 159 37 Speaker 2F F 1 2 14 186 25 Speaker 3F F 1 2 22 186 30 Speaker 4F F 1 1 21 181 38 Speaker 1M M 1 0 16 183 40 Speaker 2M M 1 2 19 193 30 Speaker 5F F 1 0 19 162 29 Speaker 6F F 2 1 21 160 32 Speaker 7F F 2 0 19 151 32 Speaker 3M M 2 2 24 190 31 Speaker 8F F 2 2 21 186 25 Speaker 9F F 2 2 21 160 31 Speaker 10F F 2 0 25 203 38 Speaker 11F F 2 1 18 175 31 Speaker 12F F 2 1 19 166 26 Speaker 13F F 2 1 23 172 30
Note. For travel frequency, “0” indicates little/no traveling, “1” indicates traveling every three to four years, and “2” indicates traveling every year. The possible range of scores on the grammar proficiency test was 1-25 points. The possible range of scores on the cultural sensitivity questionnaire was 32-224 points. The score for Spanish use was tabulated based on self-reported usage in eight different contexts. Scores ranged from 1-40, with higher scores indicating greater usage of Spanish.
4.2.1 Course level
Although unanticipated at the start of this investigation, the first individual
variable included in the analysis was course level. The participants were fairly equally
213
divided into two groups of speakers: those who were currently enrolled in a second-
semester intermediate-level Spanish course designed for HS (N = 7), and those who had
already completed this course and were thus enrolled in an upper-level language or
linguistics course (N = 9). The inclusion of HS enrolled in two different course levels
thus permits the examination of how language level, or overt level of language
instruction, may affect HS pronunciation. If HS experience a “benefit” in pronunciation
based on their early exposure to the Spanish language but not as a result of classroom
instruction, then one would expect that there would be no significant differences in vowel
production based on course level. If, however, additional exposure to Spanish via the
classroom and additional speaking do influence HS pronunciation, one would expect that
these two groups of participants would differ in terms of their vowel production.
The main effect of course level was not found to be significant in any of the
analyses conducted with the four independent variables. However, the vowel by course
level interaction was significant in the analyses of F1 (F(4, 3254.07) = 2.44, p = .046), F2
(F(4, 3254.12) = 18.11, p < .001), and Euclidean distance (F(4, 3254.13) = 8.99, p <
.001). The F1, F2 values and Euclidean distance measures calculated by the statistical
model are presented in Table 4-16.
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Table 4-16
Formant values and Euclidean distance measures for two course levels
Vowel Course level F1 (Hz) F2 (Hz) Euclidean
distance (Hz) /i/ intermediate 672.41 1533.17 244.30
advanced 703.21 1525.94 234.71 /e/ intermediate 487.36 1884.27 252.81
advanced 510.92 1901.85 300.66 /a/ intermediate 357.72 2183.81 538.92
advanced 378.99 2230.45 608.10 /o/ intermediate 534.94 1217.09 459.55 advanced 539.95 1114.97 519.58
/u/ intermediate 409.51 1287.16* 408.14* advanced 431.79 1130.52* 516.15* Note. The “*” denote a significant difference between groups.
The differences in vowel organization between the two course levels are
illustrated visually in Figure 4-30. The gray symbols represent the acoustic space for the
participants enrolled in the intermediate-level course, and the black lines represent the
vowel space produced by the participants in the advanced group.
215
Figure 4-30. HS vowel production by course level, averaged across stress, syllable type, and task.
The pairwise comparisons of the vowel by course level interaction along the F1
dimension indicated that although none of the comparisons were found to be statistically
significant, the mean difference value of the /a/ was considerably greater than the mean
difference values of the other four vowels. This difference (+/- 30.80, p < .215) indicated
that the /a/ produced by the HS in the intermediate course was overall higher (F1 = 672.
41 Hz) than the /a/ produced by the HS in the advanced classes (F1 = 703.21 Hz). The
mean difference values for the other vowels, and especially that of /o/ (+/- 5.01), were
considerably smaller, suggesting that the vowel by course level interaction for F1 was
driven by the differences in /a/. The differences in vowel height for the vowel /a/, and the
overall lack of height differences for the other four vowels, are presented in Figure 4-30.
The pairwise comparisons along the F2 dimension indicated that the vowel by
course level interaction for F2 was driven by a difference in backness of the back vowels
/u/ and /o/. The main differences between the productions of /o/ and /u/ by the
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Vowel production by course level
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participants enrolled in the two course levels are also illustrated in Figure 4-30. The
intermediate-level group pronounced /u/ with an F2 value that was significantly higher
than the advanced group, indicating that those enrolled in the intermediate-level course
produced /u/ farther front in the acoustic space than those in the advanced classes
(intermediate = 1287.16 Hz, advanced = 1130.51 Hz; p = .031). Although it was not
statistically significant, an examination of the mean difference values for /o/ also
suggested that the participants in the intermediate-level course produced /o/ considerably
farther front than the speakers in the advanced classes. The average intermediate-level
value was 1217.09 Hz, while the advanced-level HS exhibited an average of 1114.97 Hz,
resulting in a mean difference of +/- 102.11 (p = .132). The significance of this
interaction was thus influenced by the large differences between these groups with
respect to /o/ and /u/.
The backing effects of /u/ and /o/ by the advanced-level speakers were further
confirmed by the analysis of Euclidean distance. The advanced-level participants tended
to exhibit larger Euclidean distances, indicating that their vowels were dispersed farther
from the center of the vowel space than those produced by the intermediate-level
speakers. This difference was only statistically significant for /u/ (intermediate = 408.14
Hz, advanced = 516.15 Hz; mean difference = +/- 108.00 Hz; p = .031). As with the
analysis of F2, however, an examination of the mean difference values between these two
groups offers additional insight into vowel dispersion. The mean difference of /o/ was
also considerably high (+/- 60.03), indicating that the participants enrolled in the
intermediate-level course produced /o/ with a Euclidean distance that was 60 Hz closer to
the centroid than the advanced group (p = .192). The Euclidean distance measure of /i/
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from the centroid by the intermediate-level speakers was 538.91 Hz and for the
advanced-level speakers was 608.09 Hz. The mean difference value between the two
groups was 69.18 Hz, but the difference was overall not found to be statistically
significant (p = .136). The differences in vowel height, backness, and distance from the
centroid are presented in Figure 4-30.
To review, the analysis of course level thus revealed differences in the
pronunciation and acoustic distribution of HS vowels. The only vowel to marginally
show height differences between groups was /a/, which was produced higher in the
acoustic space by the intermediate group than by the advanced group. In terms of vowel
backness, the back vowels /o/ and /u/ exhibited the greatest difference based on group.
The /u/ and /o/ were both produced farther front in the vowel space by the intermediate-
level participants, but this difference was only statistically significant for /u/. The
Euclidean distance measures indicated differences in dispersion, again for the vowels /o/
and especially /u/. These vowels, but only statistically for /u/, were closer to the centroid
when produced by the intermediate-level speakers than by those in the advanced courses.
The front vowel /i/ showed an important trend: it was articulated closer to the centroid by
the intermediate group than by the advanced group. Although not all differences between
vowels were found to be statistically significant, an examination of Figure 4-30 shows an
overall trend: the advanced-level group produced vowels that were dispersed farther
from the centroid than the intermediate-level participants.
4.2.2 Frequency of travel
The frequency with which each of the participants traveled abroad was also of
interest in this investigation. As mentioned in chapter 2, previous research has shown
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that speakers who maintain strong ties with the heritage culture pronounce the heritage
language differently than those who are less connected. The participants in this study
were divided into three groups based on how frequently they traveled abroad. Those who
had never traveled abroad or had not done so in more than 8 years were grouped into the
“0-little or no travel” group (N = 4). Those who indicated that they traveled abroad every
3-4 years were placed into the “1-some/infrequent travel” group (N = 6). Finally, those
who traveled once a year (or more) or every other year to a Spanish-speaking country or
their country of heritage were assigned to the “2-frequent travel” group (N = 6).
As with the effect of course level, there was no significant main effect of travel
frequency on any of the dependent variables. The vowel by travel interaction was found
to be significant for F1 (F(8, 3254.07) = 19.72, p < .001), F2 (F(8, 3254.13) = 23.61, p <
.001), and Euclidean distance (F(8, 3254.14) = 10.77, p < .001). The formant values and
Euclidean distance measures produced by the participants in the three travel groups are
presented in
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Table 4-17. Significant differences between the formant values and Euclidean
distances are indicated by superscripted letters.
Table 4-17
Formant values and Euclidean distance measures for three travel groups
Vowel Travel group F1 (Hz) F2 (Hz) Euclidean distance (Hz)
/i/ Never (0) 369.72 2106.57c 489.36c
Infrequent (1) 347.69 2163.58 538.75c
Frequent (2) 387.65 2351.25a 692.40ab
/e/ Never (0) 498.59 1888.34 274.77
Infrequent (1) 465.79 1809.08 216.89
Frequent (2) 533.05 1981.77 338.54
/a/ Never (0) 681.61 1499.91 245.93
Infrequent (1) 629.23c 1529.14 215.57
Frequent (2) 752.61b 1559.63 257.02
/o/ Never (0) 558.28 1196.80 444.10
Infrequent (1) 505.02 1183.56 467.44
Frequent (2) 549.05 1117.73 557.16
/u/ Never (0) 423.36 1253.49 404.78
Infrequent (1) 409.03 1248.11 415.39
Frequent (2) 429.55 1124.91 566.27
Note. The symbols next to the formant values indicate significant differences between travel groups. The “a” denotes a significant difference from group 0 (no travel), a “b” denotes a significant difference from group 1 (infrequent travel), and a “c” denotes a significant difference from group 2 (frequent travel). Although not indicated here, the Euclidean distance measures for /u/ approached significance.
The distinctions between the three travel groups are presented in Figure 4-31.
The dashed line represents the frequent travel group (group 2), the solid line represents
those who travel every few years (group 1), and the dotted line represents those who do
not travel (group 0). Although not all of the differences in vowel production between
these groups were significant, an examination of this figure shows that the frequent
travelers utilized a larger portion of the vowel space relative to the other two groups.
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Figure 4-31. Vowel distribution based on frequency of travel abroad. Values averaged across stress, syllable type, and task.
A closer examination of the vowel by travel interaction along the F1 dimension
via pairwise comparisons indicated that only the vowel /a/ showed height differences
based on travel. The difference was only significant between group 1 (some travel) and
group 2 (frequent travel). The speakers who reported traveling every few years (group 1)
pronounced /a/ with a significantly lower F1 value than those who traveled every year (p
= .006). In other words, those who traveled less produced this vowel higher in the
acoustic space. The comparisons between the other two groups were not statistically
significant, nor were any other vowels significantly different with respect to height based
on travel frequency.
With respect to vowel backness, the pairwise comparisons of the F2 values
indicated that the vowel by travel interaction was driven by a significant difference in the
pronunciation of /i/. Those speakers in group 2 (frequent travel) pronounced /i/ with a
significantly higher F2 value than those speakers who did not travel at all (frequent travel
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= 2351.24 Hz, no travel = 2106.57 Hz; p = .046). Thus, the participants who spent more
time visiting the heritage country or another Spanish-speaking country pronounced /i/
farther front in the vowel space when compared to those who did not travel at all. There
were no significant differences between the frequent travelers and those who never
traveled group when compared to the infrequent travel group. No other vowel was
significantly affected by travel group. The differences between vowel height and
backness based on travel frequency are presented in Figure 4-31.
The analysis of Euclidean distance from the centroid indicated that the speakers in
group 2 (frequent travel) exhibited a significantly larger Euclidean distance of the vowel
/i/ when compared to the other two groups of travelers (group 0 = 489.36 Hz, group 1 =
538.75 Hz, group 2 = 692.40 Hz). The difference in Euclidean distance was significant
from those who never traveled at the level of p = .016 and from those who infrequently
traveled at the level of p = .045. The longer Euclidean distance indicated that the
participants who traveled abroad every year produced the /i/ significantly farther from the
centroid than the other two groups. Another interesting finding of this analysis was that
participants in the frequent travel group also produced the /u/ with a greater Euclidean
distance than the speakers in the other two travel groups. Although the difference was
not statistically significant, it closely approached significance, with the comparison
between groups 0 and 2 at the level of p = .055 and between groups 1 and 2 at the level of
p = .051. Taken together, the longer Euclidean distances revealed for the frequent
travelers’ productions of /i/ and /u/ indicate that those speakers who traveled and spent
more time abroad articulated the high vowels more peripherally.
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To summarize these findings briefly, the analysis of the effect of travel revealed
several interesting differences, but only for certain vowels. Only the point vowels
showed differences in articulation in terms of height, backness, and distance from the
centroid. The low vowel /a/ was produced significantly lower in the vowel space by
those speakers who traveled frequently, and they also produced /i/ farther front in the
vowel space when compared to the other groups. Differences in the back vowel /u/ also
approached significance, with the frequent travelers pronouncing this vowel farther back
in the vowel space than the other two groups. Overall, the results of the vowel by travel
interaction suggest that the frequency of travel to the heritage country has a significant
effect on the pronunciation of some Spanish vowels.
4.2.3 Grammar proficiency
The third continuous covariate to be discussed is the relationship between each
participant’s grammar proficiency score and their pronunciation of the Spanish vowels.
All participants completed a short grammar assessment instrument designed by Geeslin
and Gudmestad (2010) (see chapter 3, section 3.4.2.2). Each participant’s score was
included in the model to determine if there was a connection between formal grammatical
knowledge and pronunciation. Although there was no main effect of grammar score on
any of the four dependent variables, there was a significant interaction between vowel
and grammar for F1 (F(4, 3254.03) = 10.28, p < .001), F2 (F(4, 3254.07) = 23.22, p <
.001), and for Euclidean distance (F(4, 3254.05) = 4.25, p = .002). The vowel by
grammar interaction indicated that although there was no overall effect of grammar score
on F1, F2, or Euclidean distance, performance on the grammar assessment instrument
correlated with the pronunciation of certain vowels.
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Along the F1 dimension, the only vowel that was found to have a significant
parameter estimate was /o/ (6.39 t (3254.004) = 3.48, p = .001). The parameter estimate
for this vowel was 6.39, indicating a positive relationship with grammar score and the F1
of /o/. That is, as grammar score increased, there was a tendency for the F1 value of /o/
to also increase, thus resulting in a lower vowel. The estimate of the vowel /a/ also
approached significance (-3.2 t (3254.03) = -1.96, p = .05). The negative coefficient
indicated that there was an overall negative relationship between grammar score and the
F1 value of /a/. That is, as the grammar score increased, the F1 value of /a/ decreased,
resulting in it occupying a higher position within the acoustic space. An examination of
the other parameter estimates revealed that none were significantly different from zero.
Thus, there was no consistent effect of grammar score on the F1 of the vowels /e/, /i/, and
/u/ like there was for /o/ (and marginally for /a/). The differences in vowel height are
presented in Figure 4-32. For illustrative purposes, this figure plots the vowel production
of two female speakers, each with very different grammar scores. Speaker 2f had the
lowest grammar score (14 out of 25 points) and is represented by the dashed line.
Speaker 10f had the highest grammar score (25 points) and is represented by the solid
black line. The values represented are the raw, non-normalized averages produced by
each speaker and not the estimated marginal means that have been presented in previous
figures. The statistical results discussed above, however, were based on the vowel
productions of all of the speakers
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Figure 4-32. Vowel distribution based on grammar score. Speaker 2f (dashed line) had a lower grammar score than speaker 10f (solid line). Values averaged across stress, syllable type, and task.
The analysis of the relationship between grammar and vowel backness (F2)
showed that only the estimates for /i/ and /e/ were found to be statistically significant.
Both of the coefficients were negative, indicating an inverse relationship between
grammar score and vowel backness (for /i/: -33.21 t (3254.07) = 6.11, p < .001; for /e/: -
27.47 t (3254.07) = 5.36, p < .001). In other words, as the grammar score increased,
there was a tendency for the F2 values of /i/ and /e/ to decrease. Speakers with higher
grammar scores produced /i/ and /e/ farther back in the vowel space. The differences in
backness of /i/ and /e/ are presented in Figure 4-33. The vowels produced by speaker 10f,
who scored 25 points on the grammar proficiency test, and speaker 7f, who scored 19 out
of 25 points on the grammar test, are included in the figure. The dashed lines represent
speaker 7f, and show how her productions of /i/ and /e/ are farther front in the acoustic
space when compared to those of speaker 10f.
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Figure 4-33. Vowel distribution based on grammar score. Speaker 10f (solid line) had a higher grammar score than speaker 7f (dashed line). Values averaged across stress, syllable type, and task.
Finally, the interaction between vowel and grammar was found to be significant
for Euclidean distance based on the Type III Tests of Fixed Effects. A closer
examination of this interaction indicated, however, that none of the parameter estimates
for the individual vowels were significantly different from zero. A closer inspection of
the parameter estimates suggests that the interaction was driven not by differences
between the parameter estimates and zero, but rather by the differences between some of
the vowels themselves. For example, the estimate value for /u/ was -10.78 and the p –
value for this estimate was .212. This negative coefficient indicates an inverse
relationship between grammar and /u/: as grammar score increased, Euclidean distance
value decreased. Compare this value to the estimate for /a/, 4.98 (p = .216), which is
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positive.77 The difference between -10.78 and zero, and the difference between 4.98 and
zero, are both smaller than the comparison of these two parameter estimates to each
other. The distinction between the steepness of these slopes is what resulted in the
significance of this interaction, even though the parameter estimates for the vowels were
not statistically significant. The only vowel that approached significance in this
interaction was /i/ (-8.54 t (3254.05) = -1.94, p = .052). The negative coefficient
indicates that as grammar score increased, the Euclidean distance of /i/ from the centroid
decreased, but again this value only approached significance.
In summary, the participants’ scores on the grammar proficiency test were shown
to correlate with their pronunciation of certain vowels. In terms of vowel height, those
who scored higher on the grammar test tended to articulate their /o/ lower in the acoustic
space and their /a/ higher in the acoustic space when compared to participants with lower
grammar scores. The pronunciation of /i/ and /e/ was also affected, but with respect to
backness. As a participant’s grammar score increased, the F2 values of the front vowels
was found to decrease, resulting in vowels that were produced farther back in the acoustic
space. The analysis of the relationship between dispersion (Euclidean distance) and
grammar were difficult to interpret because none of the parameter estimates were found
to be significantly different from zero. All but one of the parameter estimates were
negative, indicating that there could be an inverse relationship between grammar score
77 As will be explained in greater detail later in this chapter, the parameter estimates for the individual vowels are relative to the parameter for the main effect, which in this analysis is also the vowel /u/. In the breakdown of the interaction, this value is converted to zero, and the estimates of the other vowels are compared to the zero value in order to determine their significance. Determining the coefficient of the parameter estimate and the size of the effect present for each vowel—“the interaction term” -- is actually determined based on the original parameter for the main effect. The interaction term for /a/ is thus actually negative (-5.8) because this is the difference between the main effect (-10.78) and the value reported for /a/ (4.98). As this coefficient was not found to be significant, however, it will not be discussed further here. A more in-depth explanation of the relativity of the parameter estimates is presented later in this chapter.
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and distance from the centroid. Again, these findings were not significant, and therefore
it is difficult to draw firm conclusions of the effect of grammar on dispersion based on
this data.
4.2.4 Spanish use
As mentioned in chapter three (section 3.4.2.4), each participant completed a
questionnaire and indicated the frequency with which they spoke Spanish (e.g., daily,
weekly, monthly, etc.) in a variety of contexts (e.g., at home, TV, reading magazines).
Each person was assigned a score of Spanish use based on how often they indicated that
they spoke/read/listened to Spanish in a variety of contexts (refer to chapter 3 for a
detailed description of the scoring procedure). Of the three continuous social variables,
the frequency of use of Spanish had the clearest effect on vowel height, backness, and
distance from the centroid. Although there was no overall main effect of the use of
Spanish on vowel height, backness, and dispersion, the interaction between vowel and
Spanish use was found to be significant for F1 (F(4, 3254.08) = 5.70, p < .001), F2 (F(4,
3254.13) = 30.54, p < .001), and Euclidean distance (F(4, 3254.14) = 16.95, p < .001).
Each of these interactions will be described in greater detail in the following paragraphs.
The effect of Spanish use on vowel organization and dispersion is presented in
Figure 4-34. The figure represents the overall vowel space of two male participants’
productions of vowels: speaker 1m and speaker 3m. Speaker 1m had a Spanish use score
of 40 points, indicating that he spoke and used Spanish in all of the contexts included in
the questionnaire on a daily basis (see Appendix C for all contexts). Speaker 3m had a
Spanish use score of 30 points, meaning that he spoke Spanish frequently, but not in
every context on a daily, or even weekly, basis. As will be explained in greater detail
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throughout this section, all vowels showed some kind of effect in terms of height,
backness, or Euclidean distance, such that the overall vowel space was greater for those
who spoke Spanish with the greatest frequency. The expansion effect is clearly presented
in the figure, except for the differences in the back vowel /u/, which for these two
speakers was situated in approximately the same location. The solid line represents the
overall vowel space for speaker 1m, and the dashed line represents the vowel production
of speaker 3m.
Figure 4-34. Representation of vowel production based on Spanish use. Speaker 1m (solid line) had a higher Spanish use score than speaker 3m (dashed line). Values averaged across stress, syllable type, and task.
The Table of Estimates of Fixed Effects indicated that the parameter estimates for
the vowels /a/ and /o/ were significant for F1. The coefficient for /a/ was positive,
indicating that as the use of Spanish increased (i.e., the participant reported speaking
Spanish more frequently), the F1 value of /a/ increased (2.39 t (3254.09) = 2.09, p =
.036). Thus, the /a/ was produced lower in the vowel space as the usage of Spanish
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increased. For the back vowel /o/, the coefficient was negative, revealing an inverse
relationship between Spanish use and vowel height (-2.72 t (3254.09) = -2.09, p = .036).
As Spanish use increased, the F1 value of /o/ decreased, resulting in it raising to a higher
position within the acoustic space.
Along the F2 dimension, every vowel had a parameter estimate that differed
significantly from zero.78 The parameter estimate for /u/, which also serves as the
comparison value, was -23.29 (t(10.02) = -2.77, p = .019). The negative coefficient
indicated an inverse relationship between the F2 value of this vowel and the Spanish use
score. As the Spanish use score increased, the value of F2 decreased, resulting in the /u/
situating itself farther back in the vowel space. The same pattern was observed for /o/,
which on its own had a positive coefficient (10.26 t (3254.14) = 2.58, p = .010), but the
interaction term (i.e., the sum of the coefficient for /o/ (10.26) and for /u/ (-23.29)) was
actually negative (-13.03). The negative interaction term for /o/ also indicate an inverse
relationship between Spanish use and the F2 value of /o/. As the Spanish use score
increased, the F2 value of /o/ decreased, indicating that the /o/ moved farther back in the
78 Determining the coefficient (+/-) of the parameter estimate and thus the direction and size of the effect is determined by comparing the parameter of the individual vowel to that of the main effect (which in this analysis is also the parameter for the vowel /u/). The parameter estimates are thus relative to the main effect parameter value. This relationship is referred to as the “interaction term” and it is calculated by adding the parameter estimate of the main effect to that of the individual vowel. In some cases, this results in the changing of the coefficient for the parameter value. Thus far, the comparisons between the individual vowels and the parameter estimates, or at least the significant comparisons, have not resulted in the changing of the coefficient from negative to positive or vice-versa. For F1, for example, the parameter estimate for /u/ is 1.97, and all other values are compared to it in order to determine the direction of the effect. The parameter estimate for /a/ is also positive (2.39), so the direction of the effect positive. In the case of /o/, the parameter estimate is negative (-2.722). The relative parameter estimate of /o/, or the interaction term, is thus actually -.75, but still negative. In examining the interaction between vowel and Spanish use along the F2 dimension, the parameter estimate of /u/, which is added to the other estimates to determine the interaction term, is a relatively large negative number (-23.29). All other values by themselves are positive, but when their values are determined relative to -23.29, the parameters for /a/ (18.51) and /o/ (10.26) are actually negative: -4.53 and -12.78, respectively. In the discussion of the interaction of Spanish use and vowel for F2, the parameter estimates for individual vowels will be used in parenthetical citations, but reference to their interaction terms (relative values) will also be made. This interaction term most accurately describes the direction of the effect.
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acoustic space. The low vowel /a/ also exhibited this same pattern (18.51 t(3254.14) =
5.30, p < .001; relative to /u/, the estimate is -4.53). As Spanish use increased, the F2
value of /a/ decreased, resulting in a vowel that was produced farther back in the vowel
space. The front vowels exhibited the same pattern, but in the opposite direction. Both
/i/ and /e/ had parameter estimates that were positive, thus as Spanish use increased, so
did the F2 value (for /i/: 38.38 t (3254.18) = 10.09, p < .001; for /e/: 24.91 t(3254.29) =
6.90, p < .001). The front vowels were therefore produced farther front in the vowel
space as the use of Spanish increased.
The relationship between vowel and Spanish use and the effect on Euclidean
distance confirms the results reported for F1 and F2. The parameter estimates for all
vowels except /i/ were found to be significantly different from zero. The parameter
estimate for /u/, which also serves as the comparison value, had a positive coefficient
(16.07 t(10.86) = 2.79, p = .018). Thus, as Spanish use increased, the Euclidean distance
of /u/ from the centroid also increased. The same behavior was observed for /o/, /a/, and
/e/: the distance of these vowels from the centroid also increased as Spanish use
increased.79 The overall trend revealed is that as the Spanish use score increased, the
overall dispersion in the vowels within the acoustic space also increased. Those speakers
who indicated that they spoke Spanish more frequently and in a larger number of contexts
exhibited vowel productions that were farther dispersed from the centroid.
79 On its own, the coefficient for /o/ was -9.28 (t(3254.16) = -2.89, p = .004). The interaction term, however, is positive: 6.79. As explained in the previous footnote, the coefficient, which determines the direction of the effect, is the comparison value for the main effect of Spanish use (in this case, 16.071). The same procedure was used to determine that the coefficients for /e/ and /a/ were actually positive. The parameter estimates reported in the Table of Parameter Estimates of Fixed Effects for /e/ was -6.87 (t(3254.37) = -2.36, p = .018) and for /a/ was -14.47 (t (3254.16) = -5.13, p < .001. Their relative values are both positive, however, with values of 9.19 and 1.6, respectively.
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Based on the findings presented above, there is a strong relationship between
vowel production and Spanish use. Taking into consideration the results of the analysis
on F1, F2, and Euclidean distance, the overall pattern that emerges is that those who use
Spanish more exhibit an expansion of vowels within the acoustic space and an expansion
relative to their own centroid.
4.2.5 Cultural sensitivity
The final continuous social variable to be discussed is cultural sensitivity. Each
participant completed a cultural sensitivity questionnaire at the start of the experiment
(see chapter 3, section 3.4.2.5 and Appendix E). This questionnaire contained a number
of statements that were grouped into different categories (e.g., Empathy scale, Behavioral
scale) based on the type of cultural sensitivity and/or awareness they aimed to examine.
As there were a small number of participants in this investigation, only the total score
was included in the analysis and not the scores tabulated for the different subscales. The
decision to use the total score was based partly on the inability of the statistical model to
maintain its power with so many interactions containing vowel, and partly on the small
sample size. Thus, the results reported in this section pertain only to the overall cultural
sensitivity as calculated by the sum of each of the subscales within the questionnaire.
The Mixed Linear Model again indicated no significant main effects of cultural
sensitivity on any of the four dependent variables. The interaction between vowel and
cultural sensitivity, however, was significant for F1 (F(4, 3254.07) = 2.86, p = .002) and
for Euclidean distance (F(4, 3254.14) = 4.83, p = .001). The relationship between vowel
and cultural sensitivity will be explained in greater detail below, and a comparison
between two speakers is presented in Figure 4-35.
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Although the Type III Tests of Fixed Effects indicated that the interaction
between vowel and cultural sensitivity was significant along the F1 dimension, an
examination of the parameter estimates indicated that none of the parameter estimates
were significantly different from zero. Because of the lack of significance found within
the parameter estimates of this interaction, it is again likely that the interaction was
driven by the differences between the intercepts for /u/ (-.760) and /i/ (.275). The
parameter estimate and negative coefficient for /u/ suggest that as cultural sensitivity
increased, the F1 value of /u/ decreased. In other words, /u/ was produced higher in the
acoustic space as cultural sensitivity increased. The reverse could be hypothesized for /i/,
which had a positive coefficient. Thus, as cultural sensitivity increased, the F1 of /i/ also
increased, resulting in a lower vowel. The p-values for these parameters were not
significant, however, indicating that statistically, there was no effect of cultural
sensitivity on these vowels. On a final note, the parameter for /e/ approached
significance (-.556 t (3254.03) = -.367, p = .051), suggesting that as cultural sensitivity
increased, there was a tendency for the F1 of /e/ to decrease (i.e.,, the /e/ was produced
higher in the acoustic space). Due to the lack of statistical significance and a clear and
observable pattern, however, it is inconclusive how cultural sensitivity affected the height
of HS Spanish vowels.
The interaction between vowel and cultural sensitivity was also significant for
Euclidean distance, but only the parameter estimate for the vowel /i/ was found to differ
significantly from zero ( -2.00 t (3254.03) = -2.71, p = .007). The significant effect
observed for /i/ may be related to the fact that /i/ had the largest positive parameter
estimate in the analysis of F1. The negative coefficient of the parameter estimate
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indicated that as cultural sensitivity increased, the Euclidean distance of /i/ from the
center of the vowel space decreased. In addition, and as with the analysis of F1, the
parameter estimate for /e/ also approached significance (-1.36 t (3254.11) = -1.93, p =
.053). The negative coefficient indicates an inverse relationship with cultural sensitivity:
as cultural sensitivity increased, the Euclidean distance of /e/ from the centroid decreased.
Thus, with respect to the connection between cultural sensitivity and vowel dispersion,
there was a tendency for the front vowels to move closer to the center of the vowel space
as cultural sensitivity increased, although this trend was only significant for /i/.
The effects described for F1 and Euclidean distance are represented in the Figure
4-35. The figure contains the overall vowel space for two female speakers. Speaker 2f
earned a higher score on the cultural sensitivity questionnaire (186 points) than speaker
7f (151 points). As described in the results section above, the distance of the vowel /i/
from the center of the space decreased as the cultural sensitivity increased. Also notable
is the marginal effect of /e/ raising in speaker 2f.
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Figure 4-35. Vowel distribution based on Cultural Sensitivity. Speaker 2f (dashed line) scored higher on the cultural sensitivity questionnaire than speaker 7f. Values averaged across stress, syllable type, and task.
Taken together, the results of this analysis suggest that although cultural
sensitivity may have some effect on the positioning of the front vowels and their
proximity to the center of each speaker’s vowel space, the relationship between cultural
sensitivity and vowel pronunciation was minimal. Only the parameter estimate for /i/
was found to differ significantly in the analysis of Euclidean distance. There were no
effects on F2 or duration, indicating that for this group of participants, cultural sensitivity
was not a major factor in determining how they pronounced the Spanish vowels.
4.2.6 Summary of between-subjects effects
The results of the analyses discussed in sections 4.2.1 – 4.2.5 indicated that
several of the individual variables affected vowel production. Although there were no
significant main effects on any parameter, there were significant interactions between the
variable “vowel” and all of the covariates for F1, F2, and Euclidean distance. An
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examination of the significant interactions showed that certain vowels were produced
differently based on the participants’ course level, travel frequency, grammar proficiency,
Spanish use, and cultural sensitivity.
The overall findings of course level revealed several interesting differences
between those participants who were enrolled in an intermediate-level Spanish course
and those who had already completed this course. The intermediate-level participants
produced /a/ higher in the acoustic space, and /o/ and /u/ were farther front in the vowel
space. The back vowel /u/ and marginally /i/ were closer to the centroid for the
intermediate-level participants. This suggests that the intermediate-level participants’
vowels were more condensed and that they utilized a smaller portion of the acoustic
space when compared to the advanced group. The advanced group also showed less /u/-
fronting than the intermediate group.
The effects of grammar proficiency and cultural sensitivity on HS vowel
pronunciation were less clear and less robust. The analysis on the effect of grammar
proficiency indicated that /o/ tended to lower as grammar score raised, and that the front
vowels showed a movement farther back in the vowel space as the grammar score
increased. As very few parameter estimates were found to differ significantly from zero,
it can be concluded that there is not a strong relationship between formal knowledge of
prescriptive Spanish grammar and vowel pronunciation. For cultural sensitivity, the only
significant effect was found with the vowel /i/: the Euclidean distance of /i/ decreased as
the cultural sensitivity score increased. The lack of significance in these analyses leads to
the conclusion that cultural sensitivity did not have a major impact on HS Spanish vowel
production.
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Travel frequency and Spanish use were the two individual variables that appeared
to have the greatest effect on HS vowel pronunciation. With respect to the frequency of
travel, those speakers who indicated that they traveled frequently (once every 1-2 years)
differed significantly from the other two travel groups. Most notable is that the overall
vowel space was expanded relative to the other two groups, but this difference was only
significant for the point vowels. A similar trend was observed for the use of Spanish.
Those participants who scored the highest on the Spanish use questionnaire, indicating
that they spoke the language more frequently and in a larger number of contexts, showed
greater degrees of vowel dispersion from the center of the vowel space. Thus the front
vowels were produced farther front, the back vowels farther back, and the /a/ was
lowered. These findings suggest that speakers who have a stronger connection with the
heritage culture by traveling and speaking Spanish more frequently utilize a larger
portion of the acoustic space than those who are less connected.
Interestingly, there were no overall main effects or significant interactions
between the individual variables and vowel duration. The lack of significance in these
analyses indicated that duration did not vary or show any consistent effects based on the
between-subjects variables examined in this study. Thus, although the formant values
and acoustic distribution of the vowels for each speaker significantly different, and at
times robust, the duration of HS vowels was fairly stable across the participant groups.
The lack of effects of the between-subjects variables on duration contrasts with the
results reported for the within-subjects variables, in which vowel duration was found to
be affected fairly consistently for stress, syllable type, and speech style.
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4.3 Overall summary of results
Sections 4.1 and 4.2. provided an explanation of the statistical results for the
analyses of the within- and between-subjects variables, respectively. All of the within-
subjects variables were shown to have a significant influence on the acoustic and
durational properties of HS Spanish vowels. In terms of the organization of the system,
the results indicated that the HS system exhibits five degrees of phonetic height and four
degrees of backness—subtle differences in height and backness that have not been
included in traditional descriptions of the Spanish vowel system. Upon examining the
overall vowel space, one can observe that the /i/ is produced far front in the vowel space,
the /e/ is raised and more central than what is typically described for Spanish, and the /u/
is much farther front than what would be expected in a Spanish vowel system. The
dispersion of the vowels also indicates that the system it is not symmetrical. Although
most researchers would argue against total symmetry of the Spanish vowel system, the
HS vowels analyzed in the present study occupy a shape that barely resembles a
“triangle” – a term often used to describe the Spanish vowel space.
The within-subjects variables examined in this investigation were stress, syllable
type, and speech style. All of these variables had a significant impact on the
pronunciation of HS vowels in terms of both acoustic properties (formant values and
Euclidean distance) and duration. Lexical stress had the most robust effects. Overall,
atonic vowels were found to have lower F1 values, more centralized F2 values, shorter
Euclidean distances, and shorter duration. The overall effect of lexical stress on HS
vowel production is thus shortening and centralizing atonic vowels. Although previous
research has argued for minor differences in quality and duration based on lexical stress,
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the findings reported in this study show much greater effects. As will be discussed in
greater detail in chapter 5, the stress effects may be conditioned by a variety of external
factors.
Syllable type also significantly affected HS vowel quality and quantity. In terms
of quality, the overall pattern based on the results of F1, F2, and Euclidean distance
suggests that vowels produced in closed syllables are slightly more central than those
produced in open syllables. This effect was observed especially for the point vowels /i/,
/a/, and /u/. The analysis of the Euclidean distance measure offered more insight into this
effect by showing that vowels produced in closed syllables were overall closer to the
center of the vowel space than vowels produced in open syllables. The effect of syllable
type on duration was fairly robust. Overall, vowels produced in closed syllables were
longer in duration than those produced in open syllables. A secondary analysis revealed,
however, that the voicing characteristics and manner of articulation of the following
sound played a role in duration. Vowels in contact with voiced consonants were longer
in duration than those in contact with voiceless consonants. Interesting, however, is that
the consonant which was shown to have the greatest lengthening effect on vowel duration
was voiceless: /s/. As many syllables were closed with this consonant, the longer
duration observed for vowels produced in closed syllables may have been due to a
contextual effect. This limitation and imbalance will be addressed further in the
discussion chapter.
HS vowel quality and duration were also affected by speech style. Vowels that
were produced in the most controlled speech task (i.e., the carrier phrase task) were
shown to occupy a more peripheral location the vowel space. They were dispersed
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significantly farther from the center of the vowel space when compared to the vowels
produced in the other two tasks. Vowels produced in the spontaneous speech task (i.e.,
narrative retelling) tended to be the most centralized. The vowels produced in the semi-
spontaneous speech task (i.e., picture/memory task) tended to pattern more with the
spontaneous speech than with the controlled speech, although there were some significant
differences in quality between these two tasks. Vowel duration was also significantly
affected by speech style. The shortest vowel durations were observed in the spontaneous
speech sample and the longest in the controlled speech. The overall pattern that emerges
from these analyses is that as speech style becomes more controlled, the degree of
centralization and proximity to the centroid decrease, and the vowel duration increases.
The analyses of the between-subjects variables offered insight into which
individual characteristics had the greatest influence on the pronunciation of Spanish
vowels. These analyses revealed that some of the individual characteristics might be
considered better predictors of, or more closely related to, HS vowel pronunciation.
Grammar proficiency score and cultural sensitivity were found to have little influence on
the pronunciation of HS vowels. The only vowels that were affected by grammar
proficiency were /i/, /e/, and /o/. As grammar proficiency score increased, the analyses
revealed a tendency for /o/ to be produced lower in the vowel space and for /i/ and /e/ to
be produced farther back in the vowel space. The other vowels did not exhibit any
significant effects based on grammar score. The only significant effect revealed by the
analysis of cultural sensitivity was the movement of /i/ closer to the center of the vowel
space. That there were so few effects of cultural sensitivity and grammar proficiency
suggest that these characteristics have little influence on the vowel pronunciation of this
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group of HS. The lack of effect may be due in part to the small sample size—a limitation
that will be discussed further in the following chapter.
Course level, travel frequency, and Spanish use were found to have greater
impacts on pronunciation. Although at the start of this project the inclusion of course
level was not intended, the analysis based on each participant’s class level revealed a
trend.80 Overall, the participants who formed the “advanced” group (i.e., had already
completed the intermediate-level Spanish course designed for HS), produced /u/
significantly farther back in the vowel space than those in the intermediate-level classes.
The advanced group also exhibited a vowel space that was expanded relative to the
intermediate group of HS, although the expansion was not statistically significant. The
expansion effect was also observed in the analysis of travel frequency. The statistical
tests revealed that those HS who travel abroad every year or every other year pronounced
vowels that were more dispersed. Thus, the “frequent travel” group exhibited the largest
vowel space, whereas the other two travel groups pronounced vowels that occupied a
smaller and slightly more central portion of the vowel space. The frequency of use of
Spanish also had an effect on HS vowel quality. Those participants who spoke Spanish
more frequently also produced vowels that were more peripheral and spread out within
the acoustic domain. The analyses of the parameter estimates for this variable suggest
that, in a general sense, for this group of HS, the distance of the vowels relative to the
center of the vowel space increases as Spanish use increases.
80 Interestingly, the trend observed for course level seems to contradict with the findings of the analyses on grammar score. As grammar score increased, the front vowels were shown to move backward in the acoustic space. The opposite pattern was observed based on course level. The advanced-level participants, or those who were enrolled in 300-level Spanish classes, exhibited a fronting of these vowels relative to the intermediate group. This contradiction will be addressed further in chapter 5.
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Taken together, these analyses portray the HS Spanish vowel system as differing
considerably from traditional descriptions of the Spanish vowels. Characteristics that are
typically described as not having a significant effect on Spanish vowel pronunciation
were found to have significant effects on HS vowel quality and quantity. In other cases,
differences that were expected to occur were not found to be significant (i.e., the absence
of the effect of syllable type on /e/ and /o/). Information pertaining to each individual’s
background and language use also proved to be insightful, and suggested that some
factors play a larger role in determining how the HS Spanish vowels are pronounced. A
generalized summary of all of the results is presented in Table 4-18.
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Table 4-18
Independent variable Effect
Lexical stress Atonic vowels were centralized along the F2 dimension, had shorter Euclidean distances, and shorter duration than tonic vowels.
Syllable type
Few consistent effects on height and backness; Shorter Euclidean distances (i.e., less dispersion) for vowels produced in closed syllables; Longer vowel duration in closed syllables, only significant for front vowels.
Speech style
Vowels in spontaneous speech were the most centralized and showed less dispersion than controlled speech; Shortest duration in spontaneous speech, although significant effects only observed for /o/ and /a/.
Course level Intermediate-level participants produced /u/ that was significantly farther front when compared to advanced-level participants.
Travel frequency Frequent travelers produced point vowels more peripherally and exhibited greater dispersion overall when compared to the other two travel groups.
Grammar proficiency Front vowels were produced farther back in the vowel space and /o/ was produced lower in the vowel space by those participants who scored higher on the grammar proficiency test.
Spanish use Participants who reported speaking Spanish more produced vowels that were more peripheral than those who reported less Spanish use.
Cultural sensitivity The high front vowel /i/ was produced less peripherally (i.e., closer to the centroid) as cultural sensitivity score increased.
A more in-depth analysis and explanation of the effects described in the results
chapter will be presented in the following chapter, which contains the discussion.
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5 DISCUSSION
The goal of this chapter is to revisit the research questions that guided the
investigation, explain the extent to which the hypotheses were confirmed or refuted by
the acoustic analyses, and discuss the implications of the findings. Sections 5.1 through
5.3 address each of the main research questions separately, providing a brief summary of
the findings and a more in-depth explanation of their significance. Section 5.4 provides
further discussion and interpretation of the expansion effect described in section 5.3. The
limitations of this investigation and suggestions for future research are discussed in
section 5.5. Finally, section 5.6 provides a brief summary of the discussion points.
5.1 Overall distribution and organization of HS vowels
The first research question guiding this study is presented below:
Q1: How are HS vowels organized and dispersed throughout the system, and
how does this organization and dispersion compare to traditional and acoustic
descriptions of monolingual Spanish varieties?
The analyses of the vowel pronunciation of the HS in this study revealed that the
distribution of their vowels throughout the acoustic space differs from traditional
impressionistic and acoustic descriptions of monolingual Spanish varieties in several
ways. Figure 4-1, presented in the results chapter, is replicated below as Figure 5-1, and
depicts the overall vowel space of the HS investigated in this study. The primary
differences will be described in greater detail below.
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Figure 5-1. Overall vowel space for HS of Spanish averaged across all speakers, stress contexts, syllable types, and tasks.
First and foremost, the most notable characteristic presented in the figure above is
the asymmetrical distribution and organization of HS vowels within the acoustic space.
The asymmetry conflicts with previous descriptions of Spanish vowels, which argue for a
simple, stable, symmetrical, five-vowel system (Hualde, 2005). The statistical analyses
of vowel dispersion from the center of the vowel space of each individual speaker
indicated that the lack of symmetry was significant.81 The low vowel /a/ was found to be
located the closest to the center of the vowel space, followed by the front vowel /e/. The
back vowels /o/ and /u/ did not differ and were the third closest to the center, and the
81 It could potentially be argued that the centroid measure calculated for each speaker is not the true center of the vowel space. Previous studies which have calculated the center of the vowel space for a particular speaker, or group of speakers, have employed various methods. Harmegnies and Poch Olivé (1992), for example, determined the center of the vowel space based on a projected measure of schwa. In the present study, calculating the center of the space based on the F1 and F2 values of the point vowels assumed an equal weight along the F1 and F2 dimensions. That is, there was no adjustment made to account for the fact that small differences in F1 may be more perceptible than a small difference in F2 given the different frequency ranges that the formants tend to occupy. Even if this were not the exact center of the space, however, the distance of each of the vowels was at the very least measured from a stable point within the vowel space. This limitation will be discussed later on in this chapter.
/i/
/e/
/a/
/o/
/u/
300
400
500
600
700
800
90011001300150017001900210023002500
F1 H
z
F2 Hz Overall vowel space
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front vowel /i/ was found to be the farthest from the center. If the HS vowel space were
symmetrical, as has been suggested, then one would expect that the high vowels /i/ and
/u/ would be roughly the same distance from the center of the space, and that /e/ and /o/
would be slightly closer and not differ significantly from one another. The statistical
analyses revealed that the triangular pattern typically attested for the Spanish vowel
system is not observed in the speech of bilingual HS of Spanish. The distinct pattern of
dispersion may be a characteristic specific to this group of speakers, but may also reveal
that some of the assumptions about the nature and organization of the Spanish vowel
system are not borne out when the acoustic properties of vowels are taken into
consideration.
Not only are the vowels not distributed symmetrically, but there are noticeable
differences in the interplay of height and backness between the high and the mid vowels.
The front vowels /i/ and /e/ were situated higher in the acoustic space than their back
vowel counterparts, /u/ and /o/. The statistical analyses presented in chapter 4 revealed
that the height differences were indeed significant, resulting in a five-level distinction in
phonetic vowel height. O’Rourke (2010) also reported a five-vowel distinction in height
for the bilingual and monolingual Peruvian speakers analyzed in her study. Thus, the
results of the present study support O’Rourke’s findings, suggesting that bilingual and
monolingual vowel systems exhibit fine-grained distinctions in height that cannot be
observed impressionistically.
Differences in displacement along the F2 (i.e., front-back) dimension are also
visible in Figure 5-1. The most outstanding characteristic is the position of the /u/. In
comparison to traditional descriptions of monolingual systems, the /u/ in heritage Spanish
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is significantly farther front than would be expected. For several speakers, the /u/ was
actually pronounced farther front than the /o/, and the statistical analyses revealed that the
two back vowels were not significantly different from each other with respect to F2.
O’Rourke (2010) reported similar findings for the Peruvian bilinguals, and argued that
perhaps the distinction between the back vowels in Peruvian Spanish was due to
differences in F1 (height) and not F2 (backness). The results of the present study suggest
a similar conclusion: while the front vowels /i/ and /e/ are distinguished both in terms of
height and backness, the back vowels are only differentiated by height. The cue for
vowel identity for these speakers, thus, might be differences in F1 and not F2.
Further insight into the HS vowel system is gained by examining the distribution
of all vowels within the acoustic space, as well as the overall area of the acoustic space
they occupy. Figures 5-2 and 5-3 represent all of the vowel tokens produced by the
female and male HS analyzed in this study. As the figures below contain the raw formant
frequencies and not normalized values, the female and male data are presented separately.
Each color represents one of the five Spanish vowel categories, and the shapes represent
different speakers. Although they are particularly difficult to see for the female speakers
given the large number of data points, the ellipses represent one standard deviation from
the mean.
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Figure 5-2. All vowel tokens produced by female HS (N = 2703). Green represents /i/, blue /e/, red /a/, orange /o/, and purple /u/.
Figure 5-3. All vowel tokens produced by male HS (N = 639). Purple represents /i/, blue /e/, green /a/, red /o/, and orange /u/
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The individual vowel productions presented in Figures 5-2 and 5-3 demonstrate
that the vowels produced by HS occupy specific regions within the acoustic space.
Generally speaking, the acoustic areas are maintained separately, with each vowel
occupying its own specific region within the acoustic space. The figures do, however,
reveal that some vowel categories overlap slightly, and that the degree of overlap varies
by gender.82 The greatest degree of overlap is observed for the back vowels /o/ and /u/
for both genders. The front vowels /i/ and /e/ exhibit a greater degree of separation, with
only slight overlap between these two categories. As shown in Figure 5-2, some of the
female productions of /e/ were produced far back in the vowel space, so much so that
they overlap with the most fronted productions of /o/. In contrast, the male speakers did
not exhibit as much convergence of the mid vowel categories. Some male speakers did,
however, produce a few tokens that were extremely high and back, falling within the
boundaries of the space established for /i/ and /u/. Unlike the other vowels, the acoustic
space occupied by /a/ varies height-wise for both the male and female speakers. The low,
central vowel /a/ exhibited F1 values that varied roughly between 1100 Hz and 500 Hz
for the females, and 800 Hz and 600 Hz for the males. Thus, Figure 5-2 and Figure 5-3
indicate that HS Spanish vowels tend to cluster in separate regions within the acoustic
space, and that certain vowels show more variability in their productions along the front-
back dimension (F2) whereas others vary primarily in height (F1).
82 A comparison between the female data presented in Figure 5-2 and the male data presented in Figure 5-3 suggests that the amount of overlap between the vowel categories may be somewhat greater for females than for males. The unequal number of male and female participants, however, may have resulted in Figure 5-2 (females) appearing more crowded than Figure 5-3 (males). Figure 5-2 contains 4 times as many data points as Figure 5-3, leading to the appearance of greater overlap. Although it is possible that male and female speakers would exhibit differences in pronunciation, it is not possible to address this question further given the unequal distribution of gender in this study.
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The overall cloud data presented in the figures above demonstrated some
separation of vowel categories for male and female speakers with the exception of the
back vowels. By examining just the mean values and the standard deviations from the
mean, however, a slightly different picture emerges when compared to the cloud data.
Figure 5-4 and Figure 5-5 illustrate the acoustic regions occupied by each of the vowel
categories by female and male HS, respectively. The ellipses represent two standard
deviations of F1 and F2, and the symbol in the center of the ellipse represents the mean
value of each vowel as averaged across all speakers of the same gender. The values
presented in Figure 5-4 and Figure 5-5 are non-normalized, and for this reason females
and males are presented in their own separate plots.
Figure 5-4. Dispersion of vowel categories for female HS (N = 2703). Ellipses represent two standard deviations from the non-normalized mean, and the symbol in the center of the ellipse represents the mean F1 and F2 value for each particular vowel category.
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Figure 5-5. Dispersion of vowel categories for male HS (N = 639). Ellipses represent two standard deviations from the non-normalized mean, and the symbol in the center of the ellipse represents the mean F1 and F2 value for each particular vowel category.
Figures 5-4 and 5-5 above reveal several additional characteristics regarding the
organization and dispersion of HS vowels. First of all, the shape and size of the ellipses
confirm that certain vowels showed greater variation in terms of height, whereas others
showed more movement along the front-back continuum. The low vowel /a/ in particular
showed more variation along the height (F1) dimension and less dispersion along the
front-back continuum when compared to the high vowels /i/ and /u/. The mid vowels
exhibited somewhat equal amounts of variation in terms of both height and backness, as
evidenced by the near circular shape of the area it encompassed, especially for the /e/.
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Thus, the type of variation that HS vowels exhibit is not uniform for all vowels, but rather
varies according to the vowel category. For this group of speakers, the majority of the
variation in /a/, for example, was observed in terms of height. The back vowel /u/, in
contrast, exhibited some height variation, but the movement was primarily observed
along the front-back (F2) dimension.
In addition, an examination of the ellipses confirms that there is some degree of
overlap between the vowel categories for both male and female speakers, especially when
two standard deviations from the mean are plotted.83 As can be observed above, there is
a considerable amount of overlap between the back vowel categories /o/ and /u/. This
result is not surprising given the proximity of the back vowels in the acoustic space (see
Figure 5-1). There is less overlap between /i/ and /e/, which follows given that the front
vowels exhibited a greater distance from one another in terms of pure averages when
compared to the back vowels. The mid vowel categories /e/ and /o/ showed very little
overlap, but the low vowel /a/ does encroach upon the space occupied by the mid vowels,
especially /e/.
In order to gain more perspective about the organization of the HS vowel space, the
non-normalized values for the male and female speakers in this study were compared to
those obtained by Servín and Rodríguez (2001) for male and females speakers of
Mexican Spanish. Although comparing across studies is less than ideal given that the
tasks and analysis techniques differ considerably, this comparison does offer an important
visual which illustrates the distinction between monolingual and bilingual Spanish
varieties. Figure 5-6 compares the vowel space for the female speakers based on their
83 When only one standard deviation is represented in the figures, all of the vowel categories are maintained separate, and there is no overlap.
252
utterances in the carrier phrase task to the values reported by Servín and Rodríguez
(2001). Figure 5-7 represents the same comparison for the male speakers. The dashed
lines represent the overall space produced by the HS, and the solid lines represent the
monolingual Spanish productions. Only the vowels produced in the carrier phrase tasks
are included here in order to maintain as much consistency across studies as possible.
Note also that these are the raw averages, whereas other figures have presented the
estimated marginal means determined by the statistical model. For this reason, the values
presented in these figures differ somewhat from those presented previously in chapter 4.
Figure 5-6. Comparison of vowels (N = 2703) produced by 13 female HS to vowels (N = 60) produced by 2 monolingual females in S&R (2001).
2003004005006007008009001000
7001200170022002700
F1 H
z
F2 Hz
Female HS compared to monolingual Mexican speakers in S&R (2001)
Female HS Female S&R (2001)
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Figure 5-7. Comparison of vowels (N = 639) produced by 3 male HS to vowels (N = 60) produced by 2 monolingual males in S&R (2001).
Figures 5-6 and 5-7 demonstrate that the organization of HS vowels in the
acoustic space and the amount of space they occupy differ considerably from the
monolingual speakers of Mexican Spanish examined in Servín and Rodríguez (2001).
Generally speaking, the monolingual vowel space is larger than the bilingual HS vowel
space: the high front vowel /i/ is farther front, and the /u/ is positioned farther back in the
vowel space for the monolinguals. In addition, the /a/ is positioned farther back for the
HS females, and the male and female HS also produced this vowel lower than the
monolingual speakers. The mid back vowel /o/ is slightly lowered for both the male and
the female HS when compared to the native speakers. The HS /o/ is produced farther
front than the monolingual /o/, and farther back for the female HS. Finally, as discussed
previously, the HS /u/ is situated considerably farther front than the monolingual Spanish
productions of /u/.
200
300
400
500
600
700
800
900
6001100160021002600
F1 H
z
F2 Hz
Male HS compared to monolingual Mexican speakers in S&R (2001)
Male HS Male S&R (2001)
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The fronted position of the back vowel /u/ in HS Spanish may be a consequence of
these speakers also being fluent, and some even dominant, speakers of English. The
location of the back vowel /u/ in English is known to differ from the position traditionally
described for Spanish. Bradlow (1994), for example, directly compared the production of
vowels across English, Spanish, and Greek. She reported F2 values for English ranging
between 1100 and 1300 Hz, whereas the average F2 value of Spanish /u/ was less than
1000 Hz (992 Hz in CVCV words). Chang et al. (2009) reported an even higher (i.e.,
more fronted) F2 value for English /u/-- nearly 1500 Hz. In contrast, the typical F2 value
of Spanish /u/ reported in acoustic studies of Spanish vowels falls between 700 and 900
Hz (Quilis & Esgueva, 1983; Servín & Rodríguez, 2001). In addition, the position of /u/
is known to exhibit even more fronting in certain varieties of American English as well as
in Mexican American varieties of English (Fought, 1999). Given that /u/ is produced
farther front in the vowel space in English than in Spanish, and that /u/-fronting has been
attested in varieties of Mexican American English, the fronted position of the /u/ in HS
Spanish may be induced by contact with English.84
Another distinct characteristic of the HS vowel system is the lowering and
backing of the /e/ relative to monolingual Spanish vowels. As shown in Figure 5-6, the
female participants in this study produced /e/ considerably farther back and lower than
the female monolingual speakers from Mexico City. The male HS also produced /e/
lower in the space and slightly farther back, but the degree is not nearly as great as that
exhibited by the female speakers. The pronunciation of /e/ for the HS is somewhat
consistent with the description provided by Lipski (2008) for Mexican American Spanish.
84 It is important to note, however, that O’Rourke (2010) also reported the fronting of /u/ among Spanish monolinguals and Quechua-Spanish bilinguals in Peru who do not have extensive contact with English.
255
He argued that there is a tendency for this vowel to be laxed and pronounced more like
/ɛ/, as in the word let, especially in final syllables, and that this characteristic was most
prevalent in the Midwestern United States. Although all of the vowels analyzed in this
study were non-final, it is possible that the lowering and backing of /e/ has extended to all
productions of this vowel for this group of HS, especially among the female speakers.
Whereas large differences in vowel quality were observed for HS, the analyses of
vowel duration revealed that the HS vowels patterned similarly to what has been
described for monolingual Peninsular Spanish (Marín Gálvez, 1995). Like the
monolingual speakers examined by Marín Gálvez, HS exhibited intrinsic vowel duration:
as vowel height increased, the overall duration of the vowel decreased. In this way, the
HS vowels patterned like monolingual Spanish speakers. It is important to mention,
however, that although the pattern of duration exhibited by HS and monolinguals is
similar, the HS vowels were overall longer than those produced by the monolingual
speakers reported in Marín Gálvez. The differences in monolingual and HS duration are
presented below in Figure 5-8. The black bars represent the HS vowel duration in the
CPT, and the gray bars the monolingual duration reported in Marín Gálvez, which were
obtained from a reading task.
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Figure 5-8. HS and monolingual vowel duration in controlled speech. Marín Gálvez’s (1995) data represents Peninsular Spanish.
An examination of the vowel durations for each group of speakers indicates that
HS vowels were always slightly longer than those produced by monolinguals. The
durational differences were greatest for the low vowel /a/ and least for the high vowels /i/
and /u/. As no statistical comparisons between these two populations were made,
however, it is not possible to determine if these differences were significant. Even
though HS vowel duration is slightly longer than monolingual vowel duration, the former
is more similar to the monolingual productions than it is to the L2 learner durations
reported in Stevens (2011).85 The learner durations reported in Stevens’ study exhibited
intrinsic vowel duration as well, but were upwards of 200 milliseconds in length, even for
the high vowels. Thus, unlike vowel quality, the HS vowel durations were found to differ
85 As will be discussed in greater detail in section 5.3.2, Stevens (2011) examined the Spanish vowel durations of L2 learners in study abroad and at-home contexts. He compared L2 vowel duration to monolingual Peninsular vowel duration, and reported that L2 learners produced Spanish vowels that were significantly longer than monolingual productions. The vowels he analyzed were word-final, which, as mentioned previously in chapter 3, are often lengthened in some varieties of Spanish.
0 10 20 30 40 50 60 70 80 90
/i/
/e/
/a/
/o/
/u/
Duration in ms HS and monolingual vowel duration
HS vowels Marín Gálvez (1995)
257
very little from those reported in previous studies for monolingual Peninsular Spanish.
Overall vowel duration was therefore perhaps less affected by the influence of English
than was vowel quality. This assumption will be addressed further in section 5.2.1
pertaining to lexical stress.
The analyses of HS vowel quality and duration and the comparisons between their
productions and those of monolinguals indicate that HS of Spanish exhibit a unique
system of vowel pronunciation. The aforementioned finding therefore confirms two of
the hypotheses presented in chapter 2: 1) HS of Spanish would exhibit patterns of
pronunciation that conform to sociocultural norms associated with the population, and 2)
HS vowel productions would reflect influence from English. The pronunciation of the
vowels /e/ and /u/ in HS Spanish suggests that the participants in the present study may
be integrating some characteristics of English into their Spanish vowel pronunciations,
while at the same time maintaining pronunciations associated with their heritage variety
of Spanish. The production of /u/ is more similar acoustically to the English /u/, whereas
the /e/ was produced lower and farther back, especially for females—a characteristic
described by Lipski (2008) as typical of Mexican American Spanish in the Midwestern
United States.86 As will be discussed in greater detail in sections 5.2.1 and 5.2.2 below,
however, the lowering and backing of /e/ may have been the consequence of the contact
of many of the /e/ tokens with /s/. Central Mexican varieties of Spanish are argued to
exhibit unstressed vowel reduction, especially when the vowel is followed by /s/ (Lope
Blanch, 1972). Thus, the centralized position of the /e/ could be the result of contextual
effects, as many of the stressed and unstressed productions of /e/ occurred in this context.
86 It is important to note that Mexican American Spanish is a contact variety. Thus, the laxing of /e/ described for this variety of Spanish could be contact induced. Lipski (2008) does not offer any explanation as to the cause of this lowering and backing of /e/.
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A final important aspect to discuss is the position of the /a/ in HS Spanish. As the
HS described in this investigation are residents of Chicago and surrounded by speakers
who exhibit the Northern Cities Vowel Shift in English (NCVS), it is interesting that the
position of the /a/ is still central, or at least farther back in the space than the monolingual
Spanish speakers’ /a/. The F2 values exhibited by the HS are within the range of possible
fronted /a/ tokens associated with the NCVS, but the range of variation exhibited by the
/a/ is primarily in height and not in backness. The lack of variation along the F2
dimension for /a/ suggests that the HS in this study have most likely not integrated this
particular characteristic of the NCVS into their Spanish. The lack of /a/ fronting is
somewhat consistent with Konopka and Pierrehumbert (2008; in press) who reported that
speakers of Mexican American English in Chicago did not exhibit all of the
characteristics of this English vowel shift. Thus, as the NCVS is not entirely present in
Mexican American English varieties in Chicago, the lack of /a/ fronting in heritage
Spanish is not surprising.
This section of the chapter has offered an analysis of the HS vowel system, its
internal organization and dispersion, and a comparison between HS vowel properties and
those reported for monolingual Mexican Spanish. The following sections discuss each of
the between- and within-subjects variables separately, and offer greater insight into the
role of these variables in determining the organization of the HS vowel system.
5.2 Within-subjects variables
The second research question addressed in the present investigation pertains to the
effects of three within-subjects variables on HS vowel pronunciation. This question is
presented again below:
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Q2. How do lexical stress, syllable type, and speech style affect HS vowel quality,
quantity, and dispersion?
The effects of each of the within-subjects variables are described in their own
separate subsection. Lexical stress is discussed in section 5.2.1, syllable type in section
5.2.2, and speech style in section 5.2.3.
5.2.1 Lexical stress
Of all of the analyses conducted in this dissertation, the influence of lexical stress
on HS vowel production was the most robust. HS vowels exhibited significant
differences in atonic and tonic vowel production in terms of quality, dispersion, and
quantity. The main finding was that atonic vowels were more centralized, exhibited
smaller Euclidean distances from the center of the vowel space, and were significantly
shorter in duration when compared to their tonic counterparts. The distinctions between
tonic and atonic vowels were also observed to some degree in all of the speech styles.
Thus, it was not the case that differences in stress were only observed in the most
spontaneous speech productions, but that the distinction between tonic and atonic vowels
as also observed, and was significant, in the controlled speech task.
That HS exhibit differences in quality conflicts with the argument that Spanish
vowels do not exhibit quality differences based on lexical stress (Delattre, 1969).
Although the former did report very small degrees of reduction in the form of
centralization for Spanish, the degree of reduction was considerably less than what was
reported for English. The stress differences observed for HS are, however, consistent
with the impressions of Navarro-Tomás (1918) and the findings of the acoustic
investigation conducted by Menke and Face (2010). Based on impressionistic data,
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Navarro-Tomás did argue that vowels exhibited, albeit slight, differences in quality based
on stressed context. Menke and Face (2010) also reported that L2 learners of Spanish at
varying levels, as well as the monolingual control group, produced atonic vowels that
were more centralized when compared to tonic vowels. The latter reported that the
difference was more robust along the F2 dimension, in that the atonic vowels exhibited
greater movement along the front-back continuum when compared to the height
continuum. This same tendency was also observed in HS Spanish, as all vowels except
for /a/ exhibited significant degrees of centralization along the F2 dimension, but only the
non-high vowels varied significantly according to height. Taken together, the height and
backness differences resulted in atonic productions that were raised and centered, but like
Menke and Face’s (2010) findings, the centralization effect was greater along the F2
dimension. The raising and centering of atonic vowels was further reflected by their
shorter Euclidean distances from the center of the vowel space, confirming the robustness
of the stress effect.
The atonic vowels produced by HS were also significantly shorter in duration than
the tonic vowels. The durational differences between tonic and atonic vowels are
consistent with Navarro-Tomás’s (1918) impressionistic description that atonic vowels in
Spanish are reduced. The present study also corroborates Marín Gálvez´s (1995) acoustic
results, which reported that atonic vowels were significantly shorter than tonic vowels.
However, as with the previous comparison between overall HS duration and the
monolingual values reported by Marín Gálvez, an important difference emerges. The
degree of shortening between the tonic and atonic vowels is greater for HS than for
monolinguals. The monolingual tonic vowel durations reported in Marín Gálvez were
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argued to be 20.3% longer than the atonic vowels (tonic = 70.17 milliseconds, atonic =
58.31 milliseconds). The HS in this study, however, showed more than a 45% increase in
duration between the atonic and tonic vowels (tonic = 82.04 milliseconds, atonic =
52.34). In other words, although monolingual speakers of Spanish do exhibit some
differences in duration as a consequence of lexical stress, the effect is nearly two times
greater for HS of Spanish.
Taken together, the quality and quantity differences observed in HS Spanish
indicate that this bilingual variety of Spanish exhibits robust differences in vowel
production based on lexical stress. There are two potential explanations for these
differences in quality and duration: 1) the HS in this study exhibit the unstressed vowel
reduction (UVR) that is argued to exist in central Mexico (Boyd-Bowman, 1952; Lope
Blanch, 1972; Matluck, 1952), or 2) HS have integrated characteristics typically
associated with English vowel reduction into their Spanish.87
As described in chapter 2, section 2.2.2, one notable characteristic of central
Mexican Spanish is the reduction of unstressed vowels, especially the mid vowels when
in contact with /s/. The reduction observed in this bilingual variety of Spanish could,
thus, represent the reduction reported by Boyd-Bowman (1952), Lope Blanch (1972), and
Matluck (1952). If the input that these speakers received as children consisted of a
variety which exhibited this reduction, the HS in this study could have adopted this
characteristic into their Spanish as adults.
Delforge (2008), however, argued that “reduction”, at least in Andean Spanish,
was better characterized acoustically as devoicing. The acoustic analyses of the HS
87 As few acoustic studies of monolingual Spanish vowels have directly examined the effects of lexical stress in recent years, a third possible explanation is that all Spanish dialects exhibit unstressed vowel reduction.
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vowel productions in this study, however, did not reveal great amounts of devoicing of
unstressed vowels. What is more is that the reduction affected all vowels fairly equally.
Although the mid vowel /e/ did exhibit a noticeable degree of centralization, especially
for the female speakers, all atonic vowels were centralized based on the Euclidean
distance measures calculated for each speaker. Matluck (1952) argued that /a/ in
particular was somewhat resistant to reduction in monolingual Spanish. The HS in this
study, however, produced atonic /a/ significantly higher in the vowel space than their
productions of tonic /a/. All unstressed vowels exhibited a tendency to centralize,
although the non-low vowels exhibited a greater movement along the F2 dimension
whereas the low vowel was primarily only raised. In terms of reduction with respect to
duration, all vowels again exhibited shortening in unstressed syllables as opposed to
stressed syllables. Thus, the vocalic reduction was not restricted to only the front vowels
as might be expected if this effect were attributed to a characteristic of the input variety
that these speakers overheard during childhood.88
A second potential explanation for the reduction of atonic vowels in HS Spanish
is influence from English. As mentioned previously, English is characterized by great
degrees of unstressed vowel reduction both in terms of quality and quantity. Delattre’s
(1969) instrumental study confirmed this tendency, revealing that unstressed vowels in
English reduced and centralized to the neutral vowel schwa /ǝ/ more than French,
German, and Spanish vowels. In addition, Spanish and English are typically classified as
belonging to two different rhythm classes. English is generally described as a stress-
88 Another notable finding is that the /i/ and /e/ were found to be significantly longer when produced in closed syllables as compared to open syllables. Interestingly, many of the syllables were closed by /s/. That /i/ and /e/ were longer and not shorter in this context provides further evidence against UVR (as described by Lope Blanch, 1972) as the primary cause of the lexical stress differences in HS Spanish. Further description of the effect of syllable type on duration will be provided later on in this chapter.
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timed language, meaning that it exhibits more variability in vowel durations based on the
placement of stress and a greater degree of vowel reduction (Pike, 1945; Grabe & Low,
2002; Harris & Gries, 2011). Spanish, in contrast, is typically considered a syllable-
timed language, characterized by less variability in syllable durations and lesser amounts
of reduction of unstressed vowels (Pike, 1945; Grabe & Low, 2002; Harris & Gries,
2011).
Bilingual speakers who have access to languages with different rhythmic profiles
have been shown to integrate the rhythmic characteristics of one language into their other
language. Carter (2007), for example, examined the Pairwise Vowel Variability Index
(PVI) of speakers of Spanish, Latino varieties of English in North Carolina and Texas,
Anglo-American English, and Afro-American English. He reported that the speakers of
Latino English in both North Carolina and Texas produced their English with a pattern
that was more syllable-timed (i.e., more Spanish-like) than Anglo- and Afro-American
English speakers. The Latino English PVI, however, was greater than that of the
monolingual Spanish speakers, thus indicating that their rhythmic patterns fell between
that exhibited by monolingual English and Spanish speakers. In addition, an examination
of the rhythmic pattern of one female speaker from North Carolina indicated that over the
course of two years, her English became slightly more stress-timed (i.e., English-like)
than it was when she was first interviewed shortly after her arrival to the United States
from Mexico. Therefore, these reports suggest that not only can bilingual speakers create
a modified rhythmic system, but that over time the prosodic characteristics of one of their
languages can impact the other. With reference to the HS in this study, it is possible that
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the large differences in vowel quality and quantity due to stress exhibited in their vowel
production are the result of exposure to and use of English.
The overall findings from the present investigation and the others cited above
indicate that bilingual systems of pronunciation exhibit stress effects that are traditionally
argued to be non-existent in monolingual varieties of Spanish. For HS of Mexican
heritage residing in Chicago, these lexical stress differences are manifested in terms of
both quality and quantity. Although it is possible that the lexical stress differences
produced by this group of speakers are representative of UVR known to exist in central
Mexico, it is perhaps more likely that the influence of English has resulted in the robust
degrees of centralization and reduction observed in these speakers’ productions. As
English atonic vowels are known to reduce to schwa and exhibit shorter durations, it is
possible that this stress effect is so noticeable that it is one of the first to transfer into the
speech of bilingual Spanish HS in this region.
5.2.2 Syllable type
In contrast to the results of lexical stress discussed above, the analyses of syllable
type were less robust, and revealed several unanticipated findings. The analyses of
syllable type revealed that at least for this population of HS, syllable structure had little
effect on vowel production. The effects that did emerge were not consistent: only certain
vowels exhibited differences in pronunciation based on syllable type, and some vowels
showed opposite effects in the different speech styles. One of the most interesting
findings of this analysis, however, is that not only did the mid vowels /e/ and /o/
generally not exhibit the supposed allophony claimed in previous descriptions of Spanish
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vowels (Navarro-Tomás, 1918), but that the point vowels did exhibit minor differences in
production.
Averaging across all speech styles and stress contexts, none of the HS vowels
exhibited significant differences in height based on syllable type. The lack of height
differences conflicts with the description provided by Navarro-Tomás (1918), who
claimed that the high vowels, for example, exhibited more close productions (i.e., higher)
when produced in open syllables and more open (i.e., lower) productions when they
occurred in closed syllables. An examination of the high vowels (see Figure 4-9) does
show that the vowels produced in open syllables had higher F1 values than those
produced in closed syllables, but the differences were not statistically significant.
Significant differences on the F2 dimension were interestingly only revealed for the point
vowels when averaging across all three tasks. The /u/ and /a/ were produced significantly
farther front in closed syllables and the /i/ significantly farther back when compared to
those produced in open syllables. Thus, there is some indication that the high vowels do
exhibit some of the distinctions argued by Navarro-Tomás in that they are slightly
centralized and lowered when produced in closed syllables. The finding that /a/ differed
along the F2 dimension is also interesting, given that Navarro-Tomás argued that the /a/
was central regardless of whether it was produced in a closed or open syllable. He did,
however, describe that the /a/ exhibited differences in quality when in the context of velar
and palatal consonants and diphthongs.
The analyses of the Euclidean distance measures, however, indicated a more
robust pattern. As Euclidean distance is based off of both F1 and F2, it may offer a
clearer picture of how the vowels are dispersed and organized throughout the space. The
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overall analysis of Euclidean distance showed that vowels produced in closed syllables
were closer to the center of the vowel space than those produced in open syllables. This
trend was statistically significant for all vowels when averaging across all three speech
styles. The smaller Euclidean distance measures for vowels produced in closed syllables
lead to two potential conclusions: 1) Vowels produced in closed syllables are slightly
more centralized (i.e., /a/ is higher, the non-high vowels are lower, the front vowels have
lower F2 values, and the back vowels have higher F2 values) than vowels produced in
open syllables, or 2) Vowels produced in open and closed syllables do exhibit minor
differences in pronunciation, but these differences are not noticeable when height and
backness are considered alone.
When the effects of syllable type on vowel production were examined in each of
the three tasks, significant differences in /e/ and /o/ did emerge, but were uncommon.
The closed and open tokens of /e/ were only found to differ significantly from one
another in the PIT, and only along the F2 and Euclidean dimensions. In the PIT, the /e/
in closed syllables was produced significantly farther back in the vowel space than the /e/
produced in open syllables; it was also slightly higher, although not statistically. The
backing and slight raising of /e/ in this task could be attributed to the allophonic variation
described by Navarro-Tomás, but if this were the case, then we might expect the /e/ to
have been produced lower (i.e., more open). Another explanation for this effect is the
influence of the following consonantal context, and more specifically, contact with /s/.
The PIT contained the greatest number of /e/, and also /i/, tokens in contact with /s/.
Front vowels in contact with postdental consonants typically show a lower F2 value than
those produced in null contexts, and the effect of consonantal context has generally been
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argued to affect F2 more than F1 (Stevens and House, 1963). Thus, although the /e/ may
have exhibited the allophony argued to exist by Navarro-Tomás, it is perhaps more likely
that the effect of syllable type on /e/ can be attributed to consonantal context.
The /o/ exhibited differences in height, backness, and Euclidean distance in the
NRT and only in height in the CPT. In the NRT, the /o/ produced in closed syllables was
produced farther front and lower than the /o/ produced in open syllables. The lowering
and fronting of /o/ in closed syllables is consistent with Navarro-Tomás’s description: as
predicted, /o/ produced in closed syllables had a more open articulation. In the CPT,
however, the /o/ was actually produced higher in the closed syllables than in the open
syllables, contradicting what would be expected if the effects of syllable type on vowel
pronunciation were consistent. Although no clear explanation for this reverse height
pattern can be presented at this time, it is possible that the differences in height were the
result of a task effect. The spontaneous nature of the NRT resulted in greater degrees of
centralization, thus the lowering and fronting effect observed for /o/ in this task may have
less to do with syllable structure and more to do with task. The CPT, in contrast, resulted
in more peripheral vowel productions, thus the raising of /o/ in this task could be a form
of hyperarticulation, or overshoot. The varying position, and the fact that /o/ exhibited no
differences based on syllable type in the PIT, could also indicate that syllable structure
does not have a consistent or robust effect on the pronunciation of this vowel.
That the mid vowels /e/ and /o/ exhibited few significant differences in height and
backness is perhaps the most striking finding of the overall analysis of syllable type. The
lack of an effect of syllable type on the pronunciation of the mid vowels differs greatly
from Navarro-Tomás’s detailed description of the variation argued to exist for the mid
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vowels. In contrast, the results from the present study confirm the results of other
acoustic investigations (e.g., Morrison, 2004), which suggest that the distinctions
between open and closed mid vowels do not exist in monolingual varieties. One potential
factor which could have influenced this lack of effect, however, pertains to how the
vowel tokens were coded and categorized in the present study. Navarro-Tomás argued
that syllables closed by /s/ actually resulted in a close articulation (i.e., [e] as opposed to
[ɛ]), and thus perhaps should have been coded as “open” instead of “closed” in the coding
scheme. Henríquez Ureña (1921) and Matluck (1952), however, argued that in Mexican
varieties of Spanish, /e/ in a syllable closed by any consonant (including /s/) was
produced with the open variant [ɛ] and thus differed from the Castilian variety of Spanish
described by Navarro-Tomás (1918). Servín and Rodríguez (2001), in fact, also
classified syllables closed by /s/ as “closed” syllables. To maintain consistency with
Servín and Rodríguez, syllables closed by /s/ were coded as closed syllables in the
present investigation. If Navarro-Tomás was correct, however, the coding of /e/ in the
context of /s/ as “closed” could have skewed the results, in that the analysis would have
included a disproportionate number of /e/ tokens in open syllables.
In addition to vowel quality, vowel duration also varied according to syllable
type. Vowels produced in closed syllables were found to be significantly longer than
those produced in open syllables. This lengthening effect observed in closed syllables is
consistent with the results of Marín Gálvez (1995), although the length differences
reported in his study were not statistically significant. An additional analysis of vowel
durations in the present study revealed that the voicing characteristics and manner of
articulation affected the length of the preceding vowel. Vowels tended to be longer
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when followed by voiced consonants, and were also found to be the longest when
followed by a fricative. The only vowels to show significant effects of duration based on
syllable type were /e/ and /i/. Interestingly, these vowels frequently occurred in syllables
closed by /s/. Thus, the /e/ and /i/ may have exhibited durational differences based on
syllable type as a consequence of their contact with /s/.89
The analyses conducted on syllable type indicated that HS vowels did not exhibit
consistent quality differences based on the type of syllable in which they were produced,
the mid vowels did not exhibit distinct categories based on syllable structure, and that
only the front vowels exhibited differences in duration. The aforementioned findings do
not support the hypothesis that if differences in syllable type were revealed, that they
would be the most robust for the mid vowels. The overall effect of syllable type on
duration partially confirmed the hypothesis that vowels produced in closed syllables
would be longer than those produced in open syllables, but again, the duration effect was
only found for the front vowels. As discussed previously, it is likely that the longer
durations in closed syllables were due to the front vowels’ contact with the consonant /s/.
The statistical analyses of syllable type thus have implications for how the
Spanish vowel system is described. Most traditional accounts of Spanish vowels argue
for the presence of distinct mid vowel allophones based on syllable type, and this
argument appears in numerous textbook descriptions of the system (see Hualde, 2005,
among others). The acoustic results of the present study, coupled with those of Morrison
89 The duration of /i/ and /e/ also relates to the question of whether or not the reduction of atonic vowels in HS is a consequence of UVR or a transfer effect from English. The front vowels /i/ and /e/ are argued to be the two vowels that are most subject to reduction and/or devoicing in Mexican Spanish, and especially when they are in contact with /s/. That the front vowels actually exhibited a lengthening effect when in contact with /s/suggests that HS do not exhibit the same UVR that characterizes central Mexican Spanish. The reduction of the front vowels, thus, might be better described as centralization in terms of quality, and to a lesser degree reduction in duration.
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(2004) and Servín and Rodríguez (2001), suggest that the differences attested for the
Spanish mid vowels may not be consistent or robust enough to result in statistically
distinct categories. Although slight differences in quality may emerge as a consequence
of articulatory timing and/or coarticulation, they may be so slight as to not be manifested
acoustically. The slight differences in articulation may even exist below the perceptual
level, which could explain why the HS in this study did not exhibit substantial vowel
quality differences based on syllable type. Only one of the tasks in this study was
somewhat balanced by syllable type (the PIT). A more carefully controlled study that is
balanced by consonantal context, like Morrison’s (2004) investigation, could reveal
distinct mid vowel categories. In light of his results, however, the present investigation
seems to provide further evidence against mid vowel allophony based on syllable
structure.
5.2.3 Speech style
The final within-subjects variable analyzed in this dissertation was speech style.
The main goal was to determine if and how different styles of speech influenced vowel
quality and vowel quantity in heritage Spanish. Like the results for lexical stress, the
analyses of speech style revealed robust effects on vowel quality, dispersion, and
quantity. The main findings of the analysis of speech style revealed that vowels
produced in controlled speech (the CPT) were produced more peripherally in the vowel
space than those produced in the spontaneous (NRT) and semi-spontaneous (PIT) speech
tasks and had greater Euclidean distances from the center of the vowel space. The
vowels produced in the NRT exhibited shorter durations than the other two tasks. In
many instances, the vowels produced in the NRT and PIT did not differ significantly
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from one another with respect to quality, indicating that the PIT results in speech
production that resembles that obtained from a spontaneous speech task. The vowels
produced in the PIT were more centralized than those produced in the CPT, also
suggesting that a picture identification task results in speech that differs from that
obtained in a controlled task that requires participants to read written text. Taken
together, the results described above confirm the hypotheses that vowels produced in
spontaneous speech would exhibit greater degrees of quality and quantity reduction when
compared to vowels produced in controlled speech samples.
The differences in vowel centralization, overlap, and dispersion are more clearly
represented in the vowel cloud diagrams presented below. Figure 5-9, Figure 5-10, and
Figure 5-11 plot all of the vowels produced in the CPT, PIT, and NRT, respectively. The
male and female speaker data were combined and normalized using the Lobanov (1971)
method in NORM (Thomas & Kendall, 2007) so that all of the data could be presented
together in one figure.
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Figure 5-9. Dispersion of normalized male and female vowels in the CPT (N = 984).
Figure 5-10. Dispersion of normalized male and female vowels in the PIT (N = 1247).
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Figure 5-11. Dispersion of normalized male and female vowels in the NRT (N = 1111).
As demonstrated in Figure 5-9, Figure 5-10, and Figure 5-11, the clustering and
overlap of vowel categories differ considerably based on the speech style in which the
vowels were produced. Figure 5-9, for example, represents the vowels produced in the
CPT—the most controlled speech task. There is almost complete separation of the vowel
categories in this task, with the exception of the back vowels. As shown in Figure 5-10,
which represents the PIT, there is overlap between the vowel spaces and the positions of
the vowels are more centralized than those in the CPT (Figure 5-9), but slightly less so
than the vowels produced in the NRT (Figure 5-11). Finally, in Figure 5-11, all of the
vowel categories converge upon one another, and occupy a more centralized location in
the space when compared to the vowels produced in the PIT (Figure 5-10) and CPT
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(Figure 5-9). The findings of the analyses of dispersion and overlap of vowels in the
three tasks employed in the present investigation are similar to those reported by
Harmegnies and Poch-Olivé (1992), Poch-Olivé et al (2008), and Martín Butragueño
(2011). All three of the studies mentioned above reported that vowels produced in
spontaneous speech gathered in a narrative task were more centralized and showed
greater overlap than vowels produced in a carrier phrase task. The similarities between
the previous studies and the current investigation indicate that HS, like native Spanish
monolinguals from Spain and Mexico, also produce vowels differently based on the
spontaneity of speech style.
Vowel duration also differed as function of speech style, but the effects were not
as robust as those reported for vowel quality and Euclidean distance. The overall main
effect of speech style revealed that vowels produced in the NRT had overall shorter
durations than those produced in the PIT and CPT, but that the latter two tasks did not
differ significantly from one another. The pairwise comparisons indicated that only two
vowels, namely /a/ and /o/, exhibited significantly shorter durations in the NRT when
compared to the other two tasks. The results of the analyses of duration, then, are not
identical to those revealed for vowel quality. Whereas quality and Euclidean distance
measures were similar between the NRT and PIT, similarities in duration were observed
for the PIT and CPT. In other words, the two most spontaneous speech tasks patterned
together with respect to quality, but the most controlled speech task (CPT) and the semi-
spontaneous speech task (PIT) were more similar with respect to duration.
The lack of a significant difference in duration between the PIT and the CPT may
be due to the similar nature of these two tasks. Although the PIT required identifying and
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naming objects that were presented on a screen and perhaps involved more cognitive load
than simply reading a word out loud, the utterance type was similar to that of the CPT.
The words containing the target vowels were produced at the end of a phrase in an
isolated sentence for both tasks, and the speaking rate was somewhat similar. The
similarity in the utterance type and speed at which the CPT and PIT were completed may
explain why the duration of the vowels produced in these two tasks did not differ
significantly from one another. The NRT, on the other hand, prompted rapid and
spontaneous speech, and vowels were extracted from different points throughout the
phrase, not just utterance-finally. The combination of speaking rate differences and the
analysis of vowels produced at all points throughout the phrase may explain why vowel
length was significantly shorter in the NRT than in the other two tasks. Taken together,
these findings 1) indicate that vowels produced in spontaneous speech are shorter and
more reduced in quality than those produced in carrier phrase-like tasks, and 2) suggest
that vowels produced in picture identification tasks exhibit durations that are similar to
those produced in carrier phrase tasks, but result in greater degrees of quality reduction
similar to that observed in spontaneous speech.
The quality and quantity differences observed in the different speech styles could
be further explained within the framework of H&H theory (Lindblom, 1990). According
to Lindblom, speech varies along a continuum of hypoarticulated speech, in which
phonetic targets are undershot, and hyperarticulated speech, in which the phonetic targets
are overshot. A complex interplay of listener-oriented and speaker-oriented processes
determine where along the H&H continuum a speech utterance will fall. In situations
when a lexical item is predictable and/or there are sufficient contextual cues as to the
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identity of a lexical item, the speaker will often default to a more economic means of
speaking – hypo speech. When lexical access could be impeded, a speaker may
hyperarticulate in order to ensure that the listener is able to perceive and process the
necessary lexical item or items in an utterance.
In the controlled speech task when emphasis was placed on one target word but
there were fewer contextual cues, speakers had a tendency to overshoot the vowel targets
to ensure that the target lexical item was produced and subsequently perceived clearly.
As a result, the vowels in the CPT were produced with more extreme and peripheral
formant values. In contrast, in the spontaneous speech task (NRT) when more contextual
cues to the lexical items’ identity were present, the participants undershot the vowel
target, resulting in more centralized formant values. Thus, the vowels produced in the
CPT could be classified as hyperarticulated, whereas the vowels produced in the NRT
might best be described as hypoarticulated. Evidence for hypoarticulated speech in
spontaneous speech tasks has also been reported in the studies conducted by Harmegnies
and Poch-Olivé (1992) for Spanish and Savy and Cutugno (1998) for Italian.
All in all, the analyses of speech style yield three important conclusions. First of
all, like monolingual speakers of Spanish, HS also exhibit greater centralization of
vowels in spontaneous speech when compared to controlled speech. Thus, the
aforementioned finding suggests that speech style effects are robust even in bilingual
populations. Second of all, the similarities between the NRT and the PIT indicate that a
picture identification task is an adequate means to gather semi-spontaneous speech data.
That the PIT and CPT differed also suggest that speech production tasks that do not
involve reading result in pronunciation that differs from that obtained from read-speech
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tasks. Third of all, the analyses of speech style indicate that in order to fully understand
the vowel system of a language, it is important to examine vowels produced in different
types of speech. The general consensus in the vowel literature has remained that the
Spanish vowel system is relatively stable and exhibits little variation. The assumption of
stability has been supported by acoustic studies of vowels, but most investigations have
only examined isolated vowels or words produced in highly controlled speech tasks. As
explained above and illustrated in Figure 5-9, vowels produced in controlled speech
styles are more peripheral and more closely represent the vowel triangle typically
associated with the Spanish system. An examination of vowels produced in more
spontaneous speech samples, however, offers insight into the type of variation vowels can
exhibit and the acoustic dimension on which the variation occurs.
5.3 Between-subjects variables
The third and final point of investigation in this study was to assess how several
individual variables affected HS vowel production. The third research question is
presented below:
Q3: Do individual variables influence the way in which HS pronounce their
vowels?
5.3.1 Course level
The first between-subjects variable analyzed was the relationship between each
speaker’s course level (intermediate or advanced) and vowel production. The results
indicated that participants who were enrolled in the intermediate-level grammar course
for HS produced /u/ farther front in the vowel space than those enrolled in advanced-level
courses. In addition, even though the production of the front vowels did not differ
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significantly for the two groups, the representation of the vowel space presented in
chapter 4, Figure 4-30, suggested that the vowels produced by the intermediate-level
group occupied a smaller, more centralized portion of the acoustic space when compared
to those who were enrolled in upper-level courses. The difference in the overall use of
the acoustic space between these groups is consistent with the findings reported by
Menke and Face (2010). Their analysis of advanced L2 learners of Spanish at different
levels revealed that as a speaker gained more experience with the Spanish language and
passed through different course levels, their vowel space expanded. That is, the higher
the course level, the more expanded the vowel space became. Chang et al. (2009)
reported the same pattern of expansion for native speakers, HS, and L2 learners of
Mandarin Chinese: as the level of experience with Mandarin increased, the F2 of the
back vowel /u/ decreased (i.e., moved farther back) and the F2 of the front rounded /y/
increased (i.e., moved farther front).90 The findings from the present study thus suggest
that formal classroom instruction may result in HS of Spanish producing vowels in a
more “native-like” way, if “native-like” refers to an expansion of the vowel space.91
The differences in the overall size of the vowel space produced by the
intermediate and advanced-level participants could potentially be explained, however, by
taking into consideration the distribution of male and female speakers in each of the
groups, and the fact that the statistical analyses were conducted with data that had not
90 Although Chang et al. (2009) described an expansion effect similar to that reported in this dissertation, it is important to note that the Mandarin Chinese and Spanish vowel systems differ considerably (e.g., inventory size, contrastive rounding). While the findings are parallel, the effects observed in Chang et al. may be more complex, relating to the phonemic contrast between /y/ and /u/. 91 As will be explained in section 5.4, the expansion of the vowel space may indicate that some speakers have acquired the formal speech register. In other words, it is possible that all HS are “native-like” with respect to their pronunciation of the Spanish vowels, but that only the most experienced speakers have acquired the formal register: the controlled speech style obtained in the CPT that was also the most expanded.
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been normalized using a traditional method (i.e., Lobanov, 1971). The intermediate-level
group contained two male speakers, and the advanced group only one male speaker. The
statistical analyses were conducted with non-normalized data, and generally speaking,
male speakers produce vowels with lower formant frequencies than female speakers as a
consequence of vocal tract size. Thus, the males’ low vowel /a/ was produced higher in
the acoustic space than the female speakers’ /a/, and the males’ front vowels were farther
back in the vowel space than those produced by the female speakers. The lower F1 and
F2 values of the male speakers who formed part of the intermediate-level group of
participants may have lowered the average formant frequencies of the low and front
vowels, effectively skewing the overall size and shape of the vowel space and leading to
the appearance of a smaller, more centralized space for the intermediate group. The
advanced group of speakers, however, contained more participants overall and more
female speakers, thus resulting in overall higher formant values and the appearance of
greater expansion.
In order to test the potential influence of gender distribution throughout the
groups, the normalized formant values were analyzed statistically. The analyses of
normalized F1, F2, and Euclidean distance seem to confirm that the gender distribution
may have been partly responsible for the group effect, but only with respect to the height
of the vowel /a/. Figure 5-12 below plots the normalized formant values for the
intermediate and advanced-level speakers. The gray line represents the vowel space of
the intermediate-level participants, and the black line represents the vowel production of
the advanced-level participants.
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Figure 5-12. Normalized formant values for speakers enrolled in intermediate and advanced-level courses.
When formants were normalized (see chapter 3, section 3.4.1.6) and analyzed
statistically, the effect of course level was no longer significant along the F1 dimension.92
The production of /a/ by the intermediate-level group was no longer higher in the acoustic
space than the /a/ produced by the advanced-level speakers. The effect of vowel height
for /a/ revealed in the analysis of the non-normalized formant values reported in chapter 4
thus may have been caused by the higher productions of /a/ by the two male speakers in
this group. When the values were normalized and the gender differences were removed,
the height effect was no longer observed.
The analysis of the normalized formant values also revealed that interestingly, the
vowel by course level interaction was still significant along the F2 and Euclidean
92 The vowel by stress interaction along the F1 dimension with the non-normalized data was marginal, and in fact, the only vowel that approached significance was /a/. The intermediate-level group exhibited a lower F1 value for /a/ (i.e., a higher production) than the advanced-level group. As explained with the non-normalized results, the interaction between course level and vowel was driven by the large mean difference values between the two groups’ productions of /a/, even though none of the pairwise comparisons themselves revealed significant differences.
300
350
400
450
500
550
600
100012001400160018002000
F1 H
z
F2 Hz
Normalized formant values by course level
intermediate advanced
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distance dimensions, indicating that the male participants’ lower F2 values for the front
vowels did not cause the apparent centralization effect observed for the intermediate-
level participants.93 The vowel by group interaction conducted with normalized data was
significant for F2 (F(4, 3255.05) = 4.81, p = .001) and for Euclidean distance
(F(4,3255.53) = 3.29, p = .011). In both of the interactions, the only vowel to exhibit a
significant effect was /u/. The results were therefore essentially identical to those
conducted on the non-normalized data. The pairwise comparisons of F2 indicated that
the /u/ produced by the participants in the intermediate-level course was significantly
farther front than the /u/ produced by those in the advanced courses (p = .003). The
pairwise comparisons of the Euclidean distance of /u/ indicated that the Euclidean
distance was smaller (i.e., closer to the center of the vowel space) for the intermediate-
level participants than for the advanced speakers (p = .020). Thus, even with normalized
values, the effect of course level still emerged as significant, but only for one vowel.
The analyses of normalized and non-normalized formant values thus indicate that
only /u/ exhibited significant differences in production based on course level. That the
same result was obtained in both analyses suggests that the overall vowel space of the
participants enrolled in the advanced classes was not expanded overall. Additional
classroom instruction therefore has little effect on HS vowel pronunciation. That the /u/
was the only vowel affected, however, is an important result. The /u/ was produced
farther back in the vowel space for the advanced-level group, and therefore more similar
93 Note that the analysis conducted with non-normalized formant values did not reveal a significant difference between groups with respect to their production of /i/ and /e/. Although the figure representing the overall vowel space led to the appearance of more retracted front vowels for the intermediate-level speakers, the differences were not statistically significant.
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to the position of this vowel in monolingual Spanish varieties as it is typically described
in the literature.
5.3.2 Grammar proficiency
Each participant’s score on the grammar proficiency exam was also correlated
with their pronunciation of the Spanish vowels. The results of the statistical analyses
with non-normalized data revealed that as grammar proficiency increased, the F2 values
of /i/ and /e/ decreased, resulting in front vowels that were more centralized than those
with lower grammar scores. The position of the low vowel /a/ was marginally correlated
with grammar score, such that as grammar score increased, the position of the /a/ raised.
The mid vowel /o/ also exhibited differences in F1 frequency as a function of grammar
score, exhibiting higher F1 frequencies (i.e., a lower position) as grammar proficiency
increased. Taken together, the effects of grammar proficiency on vowel production
suggested that participants with higher grammar proficiency scores had a more
condensed vowel space.
The results of the analysis of grammar proficiency thus conflict with previous
arguments that increased proficiency in a second language or heritage language results in
a more expanded vowel space (Menke & Face, 2010; Chang et al., 2009). An additional
confounding aspect is that although no official statistical tests were conducted, there
could be a connection between grammar proficiency and course level (described in the
previous section). The average grammar proficiency score for each of the course level
groups (i.e., intermediate and advanced) was calculated, revealing that the advanced-level
participants scored higher on the grammar proficiency exam (average 22.1 points) than
those enrolled in the intermediate-level classes (average 18.7 points). Based on the
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potential relationship between grammar proficiency and course level it thus might be
expected that the statistical analyses would yield similar results; the higher grammar
scores would be correlated with back vowels that were produced farther back in the
vowel space just like they were for course level, and potentially with front vowels that
were produced farther front, resulting in vowels occupying a larger acoustic space for
those with higher grammar proficiency scores.
The analysis of the connection between grammar proficiency and vowel
pronunciation described in the first paragraph of this section, however, revealed the
opposite trend: those who scored higher on the grammar proficiency exam produced the
front vowels /i/ and /e/ farther back in the vowel space – so less expanded – than those
who scored lower on the grammar proficiency test. The seemingly conflicting results of
the analyses of grammar proficiency score and course level on vowel pronunciation could
again potentially be explained based on gender distribution. For this reason, an additional
analysis was conducted with the Lobanov (1971) normalized formant values to test if the
retraction of the front vowels by the participants with higher grammar scores was at all
influenced by gender.94
The analyses of the non-normalized formant values described in section 4.2.3
indicated that as grammar proficiency increased, the F2 value of the front vowels /i/ and
/e/ decreased, resulting in a production that was farther back in the vowel space. When
the normalized formant values were analyzed statistically, however, there was no main
effect or interaction involving the F2 frequencies or the Euclidean distance measures.
Thus, the backing effect observed with non-normalized formant values was no longer
94 An examination of the grammar scores for each participant revealed that one of the males scored 24 out of 25 points. The average scores for the males and females were somewhat similar, however, with the females averaging 20.3 points and the males 19.6 points.
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significant when the normalized values were analyzed statistically. The Mixed Linear
Model conducted with the normalized formant values only revealed a significant vowel
by grammar interaction for F1 (F(4,3255.54) = 10.89, p < .001). The pairwise
comparisons of this interaction revealed that only the height of the vowel /o/ was
correlated with grammar proficiency score (4.55t(3254.37) = 4.17, p < .001). The
positive coefficient indicated that as grammar proficiency increased, the F1 value of /o/
also increased, resulting in a lower production of the vowel.
Thus, an examination of the effect of grammar proficiency on the normalized
formant values revealed a trend that differs from that revealed for the non-normalized
formant values. Only the /o/, and not the /i/ and /e/, exhibited a significant difference
based on grammar score. The combined results of the analyses conducted on course level
described in the previous section and grammar proficiency described in this section
indicate that only /u/ and /o/ differed significantly based on course level and grammar
proficiency, respectively. These results suggest that formal classroom instruction and
knowledge of prescriptive grammar may only affect the pronunciation of the back
vowels. The high back vowel /u/ was produced farther back (i.e., more “Spanish-like”)
by the participants enrolled in the advanced-level Spanish courses, and the /o/ was
produced lower by those participants with higher grammar proficiency scores, indicating
that the combination of higher course level and higher grammar proficiency scores may
result in a greater separation of the back vowel categories. Thus, as HS gain more
experience with the Spanish language and receive more formal language instruction, their
back vowel space may become more separated, and more closely resemble the
configuration that is traditionally described for monolingual Spanish vowels.
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In summary, the analyses of HS grammar proficiency and course level combined
indicated that even HS of Spanish, who are typically argued to be “native-sounding,”
may “benefit” or alter their pronunciation as a result of more formal language instruction
and increased knowledge of prescriptive grammatical structures. That the analyses
conducted with normalized and non-normalized formant values were somewhat
conflicting for grammar proficiency, however, indicates that the relationship between HS
vowel production and grammar proficiency in particularshould be interpreted with
caution. Research on HS has also suggested that paper-based grammar proficiency tests
may not be appropriate for heritage populations, given that their experience with the
Spanish language has been primarily aural and oral (Montrul, 2005). Heritage speakers
are less accustomed to formal, written proficiency tests, which may have resulted in the
grammar proficiency exam yielding inaccurate assessments of their knowledge of formal
grammatical concepts. Thus, the connection between HS course level, grammar
proficiency, and vowel production should be addressed in future investigations with
different (or additional) instruments, and with a larger sample size.
5.3.3 Travel
The frequency with which HS traveled abroad to their heritage country was found
to influence the pronunciation of their Spanish vowels.95 To briefly summarize the
results presented in section 4.2.2, only the vowels /i/ and /a/ exhibited statistically
significant differences along the F1 and F2 dimensions, respectively. The low vowel /a/
was produced significantly lower in the vowel space by participants who traveled
frequently when compared to those who traveled infrequently (i.e., every 3-4 years). The
95 The language background questionnaire only inquired how frequently each speaker traveled abroad and not how long they typically stayed in Spanish-speaking country.
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front vowel /i/ was produced significantly farther front in the vowel space by the frequent
travelers, but only when compared to those who never traveled. The Euclidean distance
of /i/ from the center of the vowel space was also found to be significantly greater for the
frequent travel group when compared to the other two groups of participants. Finally, the
same pattern was observed for /u/. The frequent travelers exhibited larger Euclidean
distances of /u/ from the center of the vowel space when compared to those who never
traveled and those who traveled infrequently, although the results only approached
significance.
Taken together, the statistical results of the vowel by travel interaction suggest
that HS who travel and spend more time abroad produce their Spanish vowels more
peripherally and exhibited greater dispersion or expansion of the vowels within the
acoustic space than those who travel less frequently. The trend of an expansion effect for
frequent travelers is an important result, and could potentially be interpreted to mean that
frequent travelers pronounce Spanish point vowels that more closely resemble
monolingual productions. Menke and Face (2010) reported that the native speakers of
Spanish examined in their study produced vowels that occupied the largest portion of the
acoustic space and were more peripheral than those produced by the groups of L2
learners. In addition, the comparisons presented in Figures 5-6 and 5-7 suggest that
native monolingual speakers of Spanish produce the point vowels more peripherally and
utilize a larger portion of the acoustic space than the HS investigated in this study.
Therefore, the expansion effect revealed via the vowel by travel interaction supports the
argument that frequent visits to the heritage country influence HS vowel pronunciation,
resulting in more native-like pronunciations.
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Although the analyses revealed few statistically significant comparisons, the
majority of the significant effects were observed between the frequent travel group and
those who never traveled. The comparisons between the speakers who never or rarely
traveled and those who traveled infrequently did not reach significance. The infrequent
travelers did, however, pronounce /a/ significantly higher than the frequent travelers, and
/i/ significantly closer to the centroid than the frequent travelers. The lack of statistically
significant differences between the infrequent travelers and those who never traveled
suggests that only regular and frequent travel has significant effects on HS vowel
production. That is, traveling every three to four years may not be sufficient exposure for
HS to alter their pronunciation. As there were a small number of participants in each of
the three groups (frequent travel N = 6, infrequent travel N = 6, no travel N=4), however,
the lack of effects between the no travel and infrequent travel groups should be
interpreted with caution.
Travel abroad may have an effect on HS vowel pronunciation for a few reasons.
First of all, traveling abroad provides additional opportunities to speak and hear Spanish
in a wider variety of contexts. Although most participants in this study indicated that
they spoke Spanish outside of the classroom on a fairly regular basis, complete
immersion results in more contact with the heritage language and the ability to speak
Spanish in contexts where it might not be understood or appropriate in the United States.
Secondly, increased input via hearing Spanish more often could also result in greater
awareness of the fine-grained details of Spanish pronunciation. Large quantities of input
may facilitate HS in creating or maintaining the phonetic categories associated with
Spanish vowels. Thirdly, HS who travel abroad more frequently may receive pressure
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from family and friends abroad to maintain their “accent” in Spanish. During informal
conversations after the experiments had been completed, several participants in this
investigation reported that their friends and grandparents abroad had commented on how
their Spanish had become English-accented. In order to maintain a stronger connection
with the heritage culture and “fit-in” during their stays abroad, some HS may make a
concerted effort to pronounce Spanish in a way that they feel is more “correct.” Those
who travel abroad more frequently may thus have more motivation to assimilate to the
native monolingual norm of vowel pronunciation than those who do not spend a
significant amount of time in their heritage country.96
The results of the present investigation also have an important connection with the
L2 literature examining the effects of context of learning (i.e., study abroad versus at-
home) on the acquisition of L2 phonology. Although some investigations have provided
mixed results in terms of the benefits of studying abroad on L2 segmental production
(e.g., Díaz-Campos, 2004), the general literature argues that study abroad learners exhibit
gains in pronunciation accuracy when compared to learners in traditional foreign
language classrooms, or “at-home” learners.97 Díaz-Campos (2006), for example,
reported that L2 learners who studied abroad exhibited higher rates of target-like
pronunciation of word-initial unaspirated /p t k/, lateral /l/, and palatal /ɲ/ in
conversational speech styles when compared to at-home learners.98 An earlier study
96 During a recent presentation, an anonymous audience member asked if I had inquired about how much Spanish the HS spoke when they traveled abroad. She indicated that when she visits her family in Mexico, she speaks English because her friends and relatives want to practice speaking English with her. The questionnaire utilized in this dissertation did not ask participants to specify which language they spoke when they traveled abroad. In the future, additional questions pertaining to how much English and Spanish is spoken while traveling should be included. 97 For a full review, see Lafford (2006). 98 Díaz-Campos (2006) is a follow up study to Díaz-Campos (2004). His 2004 investigation provided mixed results, in that the study abroad learners did not exhibit significant gains in pronunciation of the
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conducted by Simões (1996) revealed that two of the five learners who studied abroad in
Costa Rica produced fewer instances of schwa and exhibited less vowel reduction in the
posttest as compared to the pretest.99 Finally, Stevens (2011) compared the Spanish
vowel durations of study abroad learners, at-home learners, and monolingual Spanish
speakers from Spain.100 He reported that while the at-home learners did not exhibit any
gains in vowel duration, the study-abroad learners produced Spanish vowels with
significantly shorter durations in the posttest as compared to the pretest. As the
monolingual native speakers who participated in this study had shorter durations when
compared to the two L2 groups, Stevens (2011) interpreted the decrease in duration for
the study abroad learners to indicate that their vowel duration “improved” and became
more “native-like”. Another important finding of Stevens’ study was that only the point
vowels /i a u/ exhibited significant degrees of duration reduction for the study abroad
learners: the same vowels that exhibited the expansion effect (i.e., more “native-like”
pronunciation) for the HS who traveled the most frequently.
voiceless aspirated stops, voiced approximants, alveolar lateral /l/, and palatal nasal in a read-aloud text (i.e., controlled speech). The subsequent 2006 study compared not only context of learning (i.e., study abroad vs. at-home) but also the effect of speech style. When conversational speech was analyzed, the study abroad learners exhibited more target-like pronunciation than the at-home learners with respect to all segments except for the voiced approximants. 99 The methodology employed in Simões (1996) is unclear. Speech was obtained from the ACTFL Oral Proficiency Interview, and then random segments of the speech were analyzed acoustically. He explains that he randomly selected 25-30 two second segments of speech within the interviews for each speaker and then calculated the syllable nuclei “when targeted correctly” (p. 90). He does not provide further information as to what “targeted correctly” means, or exactly which portions of the syllable nuclei he examined. 100 The investigation conducted by Stevens (2011) analyzed the vowel durations produced in 40 randomized sentences containing all five Spanish vowel phonemes in stressed and unstressed position at the end of the word. The first analysis he conducted compared the durations of the L2 learners’ vowels to those of the monolinguals. The findings indicated that L2 learner Spanish vowels were significantly longer than those of the monolingual speakers. Unfortunately, no formal method was employed to control for speaking rate. Thus, the differences in duration observed between the L2 and monolingual groups could have been due to native monolingual speakers’ ability to speak faster than the L2 learners, resulting in shorter vowel durations.
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Overall, the results of the vowel by travel interaction confirmed the hypothesis
that traveling abroad would impact HS pronunciation. In addition, the findings from the
present study further support Mikulski (2010) and Duprey-Almeyda (2009), who
reported that traveling abroad and maintaining strong connections with the heritage
culture were positively correlated with HS morphosyntactic knowledge and vowel
pronunciation, respectively. The results of the present study combined with those of
Mikulski (2010), Duprey-Almeyda (2009), Díaz-Campos (2004; 2006), Simões (1996)
and Stevens (2011) suggest that just like L2 learners, HS benefit from additional
experience abroad both in terms of grammatical knowledge and pronunciation. Even HS,
who are already argued to exhibit “native-like” pronunciation, can benefit and alter their
pronunciation of vowels as the result of increased exposure to their heritage language.
5.3.4 Spanish use
Of all of the between-subjects variables analyzed in this dissertation, the use of
Spanish outside of the classroom proved to have the greatest impact on HS vowel
production. The results of the statistical analyses revealed a very clear and robust trend:
as Spanish use increased, HS Spanish vowels were more greatly dispersed and produced
in more peripheral locations within the acoustic space. As described previously in this
chapter, an expansion of the vowel space may indicate that HS more closely approximate
the vowel productions of native monolinguals of Spanish. The results of the analyses of
Spanish use and vowel production therefore confirm the hypothesis that HS who speak
Spanish more would produce vowels differently than those who use Spanish less
regularly outside of the classroom.
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The connection between Spanish use and HS morphosyntax and pronunciation on
the one hand, and Spanish use and L2 pronunciation accuracy on the other hand, has
already been established in the literature. Mikulski (2010), for example, reported that the
HS who reported speaking Spanish more outside of the classroom performed better on an
editing task when compared to HS who reported speaking Spanish less often. Au et al.
(2008), who analyzed HS who were further divided into childhood “speakers” and
childhood “overhearers,” suggested that Spanish use may have an impact on
pronunciation. They reported that HS who spoke Spanish more outside of the classroom
outperformed those who reported speaking Spanish less often, but the differences were
not statistically significant.101 Finally, although the goal of Díaz-Campos (2004) was to
examine the effects of context of learning on L2 segmental pronunciation accuracy, the
analyses revealed that speaking Spanish more regularly (i.e., 4-7 days a week and 4+
hours per day) positively correlated with L2 pronunciation accuracy. That is, those L2
learners who reported speaking Spanish more often produced Spanish sounds that were
more native-like than those who spoke Spanish less frequently. The findings of the
present dissertation indicate that additional speaking outside of the classroom does have a
significant impact on HS pronunciation as suggested by Au et al. (2008) for HS of
Spanish and by Díaz-Campos (2004) for L2 learners.
Much of the same logic used to explain the expansion effect for frequent travelers
abroad can also be applied to Spanish use. As with traveling abroad, additional speaking 101 As explained in section 2.1.2, Au et al. (2008) examined childhood speakers’ and childhood overhearers’ performance on a series of morphosyntactic and production tasks. The estimated number of hours that childhood speakers and childhood overhearers were exposed to Spanish impacted their pronunciation and the well-formedness of the constructions they produced in a narrative task. Those who were exposed to Spanish more during childhood produced a greater number of well-formed constructions in the narrative task, and exhibited more native-like VOT values. Spanish use and motivation to speak Spanish did not correlate with pronunciation, although the authors argue that the lack of an effect could have been due to the fact that they only analyzed the speech of 10 childhood speakers.
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allows for greater opportunities to establish and maintain the Spanish vowel categories.
Participants who watch movies and listen to music in Spanish on a regular basis also
receive additional auditory input that may shape pronunciation. Thus, “native-sounding”
heritage speakers benefit from additional speaking and listening practice both inside and
outside of the classroom in much the same way as L2 learners.
5.3.5 Cultural sensitivity
The final between-subjects variable examined in this dissertation was cultural
sensitivity. Previous research conducted by Alvord and Christiansen (2009) with L2
learners found a connection between cultural sensitivity and the pronunciation of the
Spanish intervocalic stops. Their findings for learners suggested that there may be a
relationship between a HS’s level of cultural sensitivity and his or her pronunciation of
Spanish vowels. The statistical analyses of cultural sensitivity conducted in the present
investigation revealed that there was little connection between this particular individual
variable and HS vowel production. The only statistically significant effect involving
cultural sensitivity was found for the Euclidean distance of /i/: the Euclidean distance of
/i/ decreased as cultural sensitivity increased. The effect of cultural sensitivity also
approached statistical significance for /e/ on the F1 and Euclidean distance measures,
suggesting that like /i/, as cultural sensitivity increased, the /e/ was produced closer to the
center of the vowel space.
As was previously mentioned in sections 5.3.2 and 5.3.3, comparisons between
native monolingual speakers of Spanish and HS both in the present study and in Menke
and Face (2010) indicate that monolinguals utilize a larger area of the acoustic space and
may pronounce Spanish vowels more peripherally than HS and L2 learners, at least on
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formal tasks. Thus far, HS who traveled more and reported speaking Spanish more often
have exhibited an expansion effect, leading to the conclusion that a more expanded vowel
space is more similar to the native-speaker norm for formal speech. Alvord and
Christiansen (2009) reported that L2 learners who scored higher on the motivation and
empathy scales produced intervocalic /b,d,g/ in a more native-like way, suggesting that
high degrees of cultural sensitivity resulted in native-like pronunciation for learners.
Thus, it might be hypothesized that HS with higher cultural sensitivity scores would
produce Spanish vowels more peripherally if there were a strong connection between
cultural sensitivity and vowel production. High levels of cultural sensitivity resulted in
/i/, and to some degree /e/, exhibiting shorter Euclidean distances, resulting in a retracted
position. If high cultural sensitivity were correlated with native-like pronunciation, the
front vowels would have been produced with longer Euclidean distance measures and
therefore more peripherally. That the front vowels were not produced farther front in the
vowel space by the participants with higher cultural sensitivity scores therefore conflicts
with the initial prediction that high degrees of cultural sensitivity would result in native-
like pronunciation.
The general lack of an effect of cultural sensitivity on HS vowel production could
be attributed to 1) the small sample size and lack of variability in scores, or 2) that only
the total cultural sensitivity score, and not the subscales, were submitted to the analysis.
Only 16 participants took part in the present study, whereas Alvord and Christiansen’s
(2009) investigation consisted of 34 participants. The sample size in the present study
may not have been large enough to statistically correlate cultural sensitivity and vowel
production. In addition, the range in cultural sensitivity scores may have been too small
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to show an effect. Although the lowest score was 151 points and the highest 203 points –
a total range of over 50 points – many of the participants exhibited scores in the range of
172 to 186 points. Thus, there may not have been sufficient variability in the scores to
reveal a significant and consistent effect. Finally, Alvord and Christiansen (2009)
analyzed the scores on the different subscales (i.e., attitudes, behavioral, motivation, etc.),
and not the total cultural sensitivity score, which is the sum of all of the subscales. As
explained in chapters 3 and 4, only the total cultural sensitivity score was analyzed in the
present study in order to maintain as much statistical power as possible given the small
number of participants. Initial exploratory statistical analyses also revealed that none of
the subscales correlated with any of the dependent variables and that only the total score
emerged as significant. Future investigations with a large sample size could potentially
test the effect of the total cultural sensitivity and each of the subscales. A larger sample
size and additional analyses could more reliably tease apart which aspects of cultural
sensitivity impact HS vowel production.
The general lack of results, and the conflict between the analysis of cultural
sensitivity and the other between-subjects variables, suggests that the effect of cultural
sensitivity on vowel production in this investigation should be interpreted with caution.
Future studies including larger subject populations may reveal a more consistent and
robust effect. At present, however, the connection between HS vowel production and
cultural sensitivity is somewhat unclear.102
102 Although the statistical analyses examining the relationship between cultural sensitivity and vowel production were not robust, the total scores on the questionnaire did reveal that overall, HS of Spanish living in Chicago exhibit high levels of cultural sensitivity. The scores ranged between 151 and 203 points. The highest possible score on the ICCS is 224 points.
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5.4 Interpreting the expansion effect
The discussion of the results presented in sections 5.3.3 and 5.3.4 of this chapter
have revealed a consistent and robust trend for expansion of the vowel space for those HS
who speak Spanish more regularly and travel more frequently. Interestingly, the
expansion effect observed for travel and Spanish use parallels the same effect reported
for speech style: vowels produced in the most controlled speech task, the CPT, were
produced more peripherally than those produced in the spontaneous and semi-
spontaneous speech tasks. If the controlled speech task represents the most formal
speech style, this parallelism could evidence that the more experienced HS have acquired,
or are closer to acquiring, the formal speaking register. In other words, does increased
exposure to, and use of, the heritage language result in the ability to modulate vowel
productions based on speech style? If so, then one might expect that the HS with more
experience with Spanish would show greater task effects than those who are less
experienced.
In order to test the possibility that more experience with the heritage language
leads to the ability to fine-tune vowel productions to represent different speech styles, an
additional interaction between vowel, task, and travel was added into the statistical model
post-hoc.103 The results of the statistical analyses indicated that this interaction was
significant for F1 (F(20, 3234.16) = 3.63, p < .001), F2 (F (20, 3234.24) = 2.68, p <
.001), and Euclidean distance (F(20, 3234.20) = 3.00, p < .001). Figures 5-13, 5-14, and
5-15 represent HS vowel production in each of the three speech styles produced by the
103 Only the interaction involving travel frequency, and not course level or Spanish use, will be discussed in this section. An exploratory analysis including the vowel by task by course level interaction was not found to be significant. An additional test including the vowel by task by Spanish use interaction was found to be significant, but only for F1, and only the height of the vowel /a/ was correlated with Spanish use.
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non-travelers, infrequent travelers, and frequent travelers, respectively. Given the
complexity of this interaction (five vowels by three travel groups by three tasks), a more
generalized description will be presented following the figures and will be organized by
dependent variable (i.e., F1, F2, Euclidean distance). The tables of Fixed Effects and the
pairwise comparisons of this interaction can be viewed in Appendix M.
Figure 5-13. Vowel production in three speech tasks for the non-travel group (N = 4). Values based on the estimated marginal means, and averaged across all stress and syllable types.
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Figure 5-14. Vowel production in three speech tasks for the infrequent travel group (N = 6). Values based on the estimated marginal means, and averaged across all stress and syllable types.
Figure 5-15. Vowel production in three speech tasks for the frequent travel group (N = 6). Values based on the estimated marginal means, and averaged across all stress and syllable types.
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Vowel production in three tasks by infrequent travelers
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The results of the interaction on F1 did not reveal a clear and consistent pattern to
suggest greater or lesser height differences across tasks based on travel frequency.
Generally speaking, all three groups showed significant differences in height for all
vowels between the NRT (most spontaneous) and the CPT (most controlled). The
infrequent travelers presented in Figure 5-14 did not produce /o/ with any significant
differences in height across the three tasks. The frequent travelers presented in Figure 5-
15 did not exhibit any significant height differences across tasks for the vowel /u/. The
non-travelers, shown in Figure 5-13, actually exhibited the largest number of differences
in height across tasks. For the non-travelers, the F1 values in the NRT and CPT differed
for all vowels: /a/ produced in the CPT was significantly lower than the /a/ in the NRT,
and /e/, /i/, /o/, and /u/ produced in the CPT were significantly higher than the same
vowels in the NRT. The statistical results, therefore, do not support the hypothesis that
more experienced HS would show greater task effects, at least not with respect to vowel
height.
The analyses conducted with F2 and Euclidean distance, however, suggest that
non-travelers did exhibit fewer distinctions in vowel backness and dispersion across the
three tasks than those who reported traveling abroad more often. The pairwise
comparisons of the interaction involving F2 revealed that the non-travelers did not
produce the vowels /a/ and /o/ significantly differently across tasks. In contrast, all
vowels produced by the infrequent travelers, and all vowels except for /a/ for the frequent
travelers, exhibited significant differences in backness: the front vowels produced in the
CPT were produced significantly farther front than those produced in the NRT, and the
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back vowels produced in the CPT were significantly farther back than those produced in
the NRT.
The analyses of the interaction with Euclidean distance revealed findings similar
to those reported for F2. For the infrequent and frequent travelers, the Euclidean
distances of all vowels were significantly longer (i.e., farther from the centroid and more
peripheral) in the CPT when compared to at least one of the other tasks.104 The
Euclidean distances of the vowels /a/ and /o/ produced by the non-travelers, however,
were not statistically different when comparing across tasks. That is, speech style did not
significantly impact the distance of /a/ and /o/ from the center of the vowel space for this
group of HS. Therefore, the results of the analysis indicate that while the infrequent and
frequent travelers produced all vowels in the CPT more peripherally and more dispersed
than the vowels produced in the other two tasks, the non-travelers did not exhibit this
distinction for all five vowels.
The results of the additional interaction between vowel, task, and travel suggest
that more experience with Spanish via traveling to the heritage country regularly not only
results in a more expanded vowel space, but may also promote the acquisition of fine-
grained differences in pronunciation associated with speech style. The non-travelers did
not produce /a/ and /o/ significantly differently across tasks, indicating that they may not
have the experience and ability to adjust their pronunciation of these two vowel sounds to
correspond with speech style. As there were few participants in each group, however, the
results of this interaction should be interpreted cautiously. Future investigations with a
104 Differences were primarily significant between the CPT (most controlled) and the NRT (most spontaneous), although in some cases all three comparisons were significant. For the frequent travelers, the Euclidean distance of /u/ in the CPT was significantly longer than that produced in the PIT, but not the NRT.
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larger number of participants should be conducted, and may reveal more robust and
consistent effects than those described here. Additional variables such as 1) length of
stay and 2) which languages and language registers are used during visits abroad may
offer additional insight into the connection between traveling abroad and the acquisition
of fine-tuned distinctions in speech styles.
5.5 Limitations and future directions
Despite the interesting and important findings described in chapter 4, the present
investigation does have some limitations. The purpose of this section of the chapter is to
discuss some of these limitations, and describe how they might be addressed in future
studies. Section 5.5.1 discusses some of the issues with the experimental design and how
they might be addressed in future studies. Section 5.5.2 explains the connection between
language and identity that was unfortunately not examined in the present study. Finally,
section 5.5.3 acknowledges the lack of comparison between HS vowel productions and
monolingual control groups.
5.5.1 Experimental design
The instruments utilized in this investigation were designed to examine the
production of vowels in different speech styles. The narrative retelling task (NRT) was
aimed at gathering spontaneous speech while at the same time providing some control
over the lexical items and vowels produced by each speaker. In other words, based on
the objects that appeared throughout the video, there was some consistency among
speakers as to how they retold the story and the words they used to describe the plot of
the film. Unfortunately, some participants were much more detailed in their retelling of
the story than others, resulting in an unequal number of vowels produced by each
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speaker. Whereas some participants spent nearly five minutes recalling as many details
as possible, others only spoke for one to two minutes and provided a basic summary of
the movie. Thus, although some participants produced well over 100 analyzable vowels
in this task, others produced only 50.
The NRT posed two additional difficulties. First, it was not always possible to
obtain examples of all five Spanish vowels in the four contexts of interest (i.e., atonic
open, atonic closed, tonic open, tonic closed). Although tonic and atonic vowels in open
syllables were easily obtained for all speakers, analyzable vowels in closed syllables were
infrequently encountered in this task. The lack of examples in all four categories for each
individual speaker was part of the reason why individual analyses of three-way
interactions were not always possible, and motivated the need for a pooled analysis. In
other words, the vowel by task by syllable type interaction would not have provided
sufficient data to yield interpretable findings for a participant who did not produce atonic,
closed /u/ in the narrative retelling task, because there would have no vowel to compare
across the three speech styles. When the data were pooled across all speakers, however, a
sufficient number of tokens in all four categories were present, allowing for the
comparison of stress type and syllable type across the three tasks. Ideally, multiple
examples of each of the five Spanish vowels should have been analyzed in each of the
four contexts for each participant in all tasks. In spontaneous speech samples, however,
the investigator is not always afforded the ability to control the output enough to obtain a
balanced corpus. Thus, future investigations of HS Spanish vowels could focus on
creating narrative retelling/spontaneous speech instruments that are carefully designed to
prompt sufficient tokens in both stress types and syllable types.
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Second, in contrast to the PIT and CPT, vowels were extracted from different types
of lexical items in the NRT, and also from different portions throughout the phrase. In
addition to analyzing vowels produced in nouns, vowel tokens were also extracted from
verbs and adjectives. In the other two tasks (the PIT and CPT), only nouns were
analyzed. Although lexical words (i.e., nouns, verbs, adjectives, and adverbs) tend to
pattern together with respect to lexical stress, there may be differences in the way that
vowels are produced in the different word classes. In addition, the vowel tokens analyzed
in the NRT occurred in varying positions within the phrase, and were not phrase-final as
they were in the other two tasks. As Schmidt and Willis (2011) showed that phrase
position can result in different rates of /s/ voicing in Mexican Spanish, it may also be
possible that phrasal position influences vowel pronunciation as well. Thus, the
combination of different word classes and different positions within the phrase may have
introduced more variability into the analyses than was intended. Word class and phrasal
position are thus two variables that could be included in future investigations of vowel
pronunciation.
The picture identification task (PIT) and carrier phrase tasks (CPT) also posed
several difficulties. First and foremost, the vowels analyzed in the PIT and CPT were
embedded within a variety of consonantal contexts. Thus, neither of the tasks was
completely phonetically balanced (see Appendix A for the words presented in the PIT
and Appendix B for the CPT). The PIT was balanced by stress type and syllable type,
but as the goal of the task was to obtain speech that was not read, the lexical items had to
be represented by pictures. It was too difficult to find words that were frequent enough
and identifiable enough to be represented by images in addition to phonetically balancing
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the PIT. The CPT was slightly more balanced in that it included all five Spanish vowels
embedded within the context of /p,t,k,s/. The CPT included additional words in order to
obtain atonic vowels and vowel tokens in closed syllables, but the following consonantal
context was variable and included many voiceless consonants. Although the F1 and F2
measurements were extracted at the midpoint of each vowel in an attempt to reduce the
influence of the following context, Stevens and House (1963) reported differences in
vowel pronunciation based on context even when the steady-state portion was measured.
The lack of phonetic balance in the CPT and especially the PIT could have introduced
unintended variability into the vowel productions of the HS examined in the present
study.
Secondly, in both tasks, many of the syllables were closed by the consonant /s/.
The inclusion of /s/ as a closing consonant could have significantly impacted the formant
values of vowels, as well as potentially introduced a new variable into the analyses of
syllable type. With respect to the effect of /s/ on the formant values of vowels, Stevens
and House (1963) reported differences in vowel pronunciation based on both voicing and
manner of articulation. Vowels produced in the context of voiceless consonants
exhibited higher F1 values than those produced in the context of voiced consonants.
Thus, a voiceless consonantal context resulted in a vowel that was produced lower in the
acoustic space when compared to vowels produced in a voiced context. An examination
of stop, fricative, and null contexts in Stevens and House’s study revealed additional
differences in vowel pronunciation based on manner of articulation. The effect of
manner of articulation was not consistent along the F1 dimension, but the F2 values of
the front vowels especially were shown to differ. Front vowels produced in the context
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of a fricative consonant exhibited lower F2 values than those produced in the context of
stops and in the null context. Thus, front vowels in the context of a fricative were
produced farther back in the acoustic space than vowels produced in the other two
contexts.
Based on Stevens and House’s (1963) findings, one might predict that front vowels
in the context of a voiceless fricative /s/ would be produced lower and farther back in the
acoustic space: the exact pattern observed for the pronunciation of HS /e/. The peculiar
position of the HS /e/ has already been described in this chapter in section 5.1. Although
the lowering and backing could be the result of laxing and the influence of English as
described by Lipski (1994), contact with /s/ may also be partly responsible for the
lowered and backed position of the /e/ in HS Spanish when compared to monolingual
Spanish varieties (see Figure 5-6 and Figure 5-7 for a comparison). That the /e/ was also
produced farther back in the vowel space in the NRT (spontaneous speech task) in which
there was much less contact with /s/, however, indicates that consonantal context may not
be the sole reason for the position of /e/ within the acoustic space. Although it is possible
that a combination of these influences (i.e., English contact or contact with /s) contributed
to the way in which HS produced their /e/ in Spanish, the influence of /s/ could be
determined by simply excluding all of the vowel tokens in contact with /s/ and
reanalyzing the data. A reanalysis without /s/ would reveal the influence of this
particular voiceless fricative consonant on the acoustic properties of vowels, and indicate
if the lowered and backed articulation of the /e/ was indeed due to contact with /s/ or if it
was more likely caused by contact with English.
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The consonant /s/ was included primarily as a means to close a syllable in which a
vowel occurred so that the effect of syllable type on HS vowel production could be
analyzed. The phonotactic constraints of Spanish are more restrictive than English, and
therefore Spanish exhibits a simpler syllable structure and fewer consonant clusters than
English. Consonant clusters beginning with /s/ are prohibited in the onset in Spanish,
resulting in the /s/ forming part of the coda of the preceding syllable. As designing the
PIT was already difficult due to the necessity of including common items representable
by pictures, one of the simplest ways to close a syllable in this task was to select words
that included /s/ plus another consonant. The /s/ was the most frequent closing consonant,
almost to the exclusion of all other consonants (see Appendix A and Appendix B).
Including /s/ as a closing consonant resulted in a conflict with Navarro-Tomás’s
(1918) description of the contexts in which the close and open vowel allophones were
argued to occur. He argued that for peninsular Spanish, syllables closed by /s/ actually
prompted the close allophone of /e/ (i.e., [e]), and not the open [ɛ] that was argued to
occur in syllables closed by most other consonants. In contrast, Matluck (1952) argued
that in Mexican varieties of Spanish, the open [ɛ] did occur in syllables closed by /s/.
Thus, the vowel tokens that were closed by /s/ were coded as “closed” in the present
study as opposed to “open” had the analysis provided by Navarro-Tomás been strictly
followed. The absence of the effect of syllable type may have been due to the coding
scheme utilized in the present study and the lack of a variety of consonants in the words
containing closed syllables. Future investigations of HS vowels and Spanish vowels in
general could focus on including more phonetically balanced instruments, excluding /s/
entirely, or analyzing vowels in contact with /s/ separately from vowels in contact with
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other consonants. The vowels in contact with /s/ in the present study could also be
recoded as “open,” and the analyses could be conducted a second time. The results of a
secondary analysis with recoded data could offer insight into the effect of the following
consonant /s/ on HS vowel production. Robust syllable type effects with recoded data
would indicate that the tokens were initially coded incorrectly, and lend evidence in
support of Navarro-Tomás’s (1918) argument that /e/ in the context of /s/ is actually
produced as close [e].
A final limitation in the experimental design of the present study is that the lexical
items included in the PIT and CPT were not balanced by lexical frequency or
neighborhood density, and included some cognates. Although both tasks, and especially
the PIT, were designed to include identifiable items and terms for common objects, food,
and animals, some of the lexical items were arguably less common than others. Several
participants had difficulty remembering terms like ostras (“oysters”), or difficulty
pronouncing words in the CPT such as cuscurro (“crouton”). Previous research has
indicated that lexical frequency and neighborhood density influence spoken word
recognition as well as speech production (Luce & Pisoni, 1998; Bybee, 2001; Vitevitch &
Stamer, 2006; Vitevitch & Stamer, 2009; Munson & Solomon, 2004; Yao, 2011).
Words with high lexical frequency have a greater tendency to exhibit reduction than low
frequency words (Bybee, 2001). Additional studies have indicated that neighborhood
density (i.e., whether a word has a high or low number of phonological neighbors) also
plays a role in speech production (Munson & Solomon, 2004; Yao, 2011). Munson and
Solomon (2004), for example, reported that lexically difficult words (i.e., low frequency
words with many phonological neighbors) were produced with greater vowel space
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expansion than lexically easy (i.e., high frequency words with few phonological
neighbors). Yao (2011) also reported that words in high density neighborhoods consisted
of vowels that were shorter in duration and also more centralized than those in sparse
neighborhoods. Although the centralization and shortening effects of lexical frequency
and neighborhood density are well-supported for English, two investigations by Vitevitch
and Stamer (2006; 2009) suggest that processing may vary across languages. Their
investigations of picture naming tasks in Spanish revealed a trend that is the opposite of
what is typically described for English: participants named Spanish words from dense
phonological neighborhoods more slowly than those in sparse neighborhoods.
As no formal measures of lexical frequency or neighborhood density were
calculated for the words included in this study, it is not possible at this time the analyze
the extent to which these characteristics influenced HS vowel pronunciation. Based on
Vitevitch and Stamer’s (2006; 2009) findings, which conflict with those reported for
English, it is unclear how frequency and density would affect the pronunciation of HS
Spanish vowels. The complex nature of the bilingual lexicon, lexical access and priming
effects, and the role of frequency and neighborhood density could be explored in future
investigations. The corpora utilized in future studies could carefully control for
frequency and density in order to compare the pronunciation of vowels in high and low
frequency words that belong to dense and sparse neighborhoods.
In addition, several words utilized in the PIT and CPT were cognates with English
words. The word eclipse (“eclipse”), for example, was sometimes pronounced in its
English form, resulting in its elimination from the analysis. In fact, the inclusion of
eclipse in the third task may have resulted in the extremely high and fronted /e/ that was
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produced in the CPT. As discussed in 4.1.2.1, the atonic /e/ in the CPT did not exhibit
centralization like it did in the other two tasks, which may have been caused by the some
of the atonic tokens being extracted from the word eclipse. In English, the first vowel is
pronounced as the high front vowel /i/. The participants’ knowledge and familiarity with
the English translation of “eclipse” may have resulted in their altering their pronunciation
and producing a vowel that was higher and farther front. Additional cognates included
eskeletos (“skeletons”), tostadora (“toaster”), cristales (“cristals”), and espaguetis
(“spaghetti”). The inclusion of cognates in these two tasks was a methodological
oversight that could have a significant impact on the pronunciation of the vowels within
these particular words. When the cognates were pronounced in their English form or
were Anglicized, they were excluded from the statistical analyses.105 Future
investigations of Spanish vowels, and especially of bilingual vowels, should focus on
excluding cognates, or examining cognate and non-cognate words separately.
Taken together, the limitations described in this section of the chapter suggest ways
in which speech elicitation instruments could be improved in future studies of HS and
monolingual Spanish vowels. Future investigations could utilize different spontaneous
speech instruments to ensure that a more equal number of Spanish vowels are obtained.
True spontaneous speech data in the form of sociolinguistic interviews could also be
examined, which may yield results that differ from spontaneous speech gathered in semi-
directed narratives. In addition, picture identification and carrier phrase tasks should be
comprised of more phonetically balanced corpora, and the inclusion of vowels in contact
105 Cognates were selectively excluded based on a variety of cues. If the lexical items were pronounced in English or were Anglicized, they were not included in the analysis. For example, if the /t/ in “espaguetis” was pronounced as a flap, the vowels were not included in the analysis. If the final /e/ was not produced in “eclipse,” or the initial vowel was not produced with F1 and F2 values within the range of /e/ tokens for that particular speaker, the vowels extracted from this word were excluded.
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with /s/ could be analyzed separately and with caution. Finally, lexical frequency and
neighborhood density may have a significant impact on HS vowel pronunciation and
could be examined in greater detail in future studies.
5.5.2 Language and identity
One individual characteristic that may have a significant impact on HS vowel
pronunciation is the connection between pronunciation and identity. As explained by
Gatbonton et al. (2005, p. 491), a speaker’s accent, or pronunciation of certain segments,
is one of the most “visible” indicators of one’s ethnic group, and can also prompt
stereotyping. They suggest that bilingual speakers and language learners with more than
one social group affiliation will sometimes alter speech to avoid stereotyping and
ridicule, or change their speech practices in order to suppress or emphasize one of their
identities (p. 492). An L2 learner, for example, who wishes to remain loyal to the home
ethnic group may purposely pronounce the L2 with an accent in order to maintain ties
with their home identity, whereas in other situations, the learner may strive to pronounce
the L2 differently because they see a reward in mastering the L2 and gaining membership
in another ethnic or social group (Gatbonton et al, 2005, p. 505). A third alternative is
that the learner or bilingual will learn which aspects of the pronunciation signal group
affiliation, and choose to only alter those specific characteristics when speaking in one or
the other of their two languages (Gatbonton et al, 2005, p. 506). In many ways, the
bilingual speaker and the L2 learner are faced with the challenge of deciding in which
ethnic or social group they desire membership, how they can signal that membership, and
the consequences of this decision with respect to social ties with other groups.
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Not all instances of language contact result in suppressing or stressing one of the
bilinguals’ identities, however. In fact, in some cases, bicultural speakers will integrate
characteristics associated with both heritages in order express their cultural and linguistic
hybridity. Potowski and Matts (2008), for example, investigated the connection between
language and identity among MexiRican young adults living in Chicago. MexiRicans are
speakers of mixed parentage, with one parent of Mexican heritage and the other of Puerto
Rican heritage. Twenty-four MexiRican young adults responded to a series of questions,
including how they would categorize their own speech (i.e., as either Mexican Spanish or
Puerto Rican Spanish), how they self-identified, and how strongly they felt that speaking
Spanish signaled their identity.106 In addition, the participants completed several speech
elicitation and vocabulary tasks that were later rated as either “Mexican” or “Puerto
Rican” by a group of outside observers with varying backgrounds.107
Potowski and Matts (2008) reported that many of the participants were clearly
rated as either Mexican or Puerto Rican, and that the ratings assigned by the outside
listeners often coincided with the way the speakers had identified their own speech.108
Several participants, however, were found to exhibit dialectal characteristics associated
with both Mexican and Puerto Rican varieties of Spanish, such as mixing syllable-final
/s/ retention (typically Mexican) with rhotacism (typically Puerto Rican). Some
106 Potowski and Matts (2008) examined several other aspects of the MexiRican community. In addition to basic questions about family history, background, and language use, participants were also asked to discuss their participation in cultural activities, what type of music they listened to, their attitudes towards Spanish, and to explain their awareness of stereotypes associated with each of their heritages. 107 The outside raters were the following: two Mexican Americans, one mainland US-raised Puerto Rican, one island-raised Puerto Rican, one island-raised Dominican, and three Anglo-Americans who were fluent in Spanish. The raters were asked to listen to the story told by each of the participants and indicate if the speaker was 1) definitely Mexican, 2) probably Mexican, 3) unsure/neither, 4) probably Puerto Rican, and 5) definitely Puerto Rican. Each rater was then asked to indicate why they made their choice, and which characteristics signaled the dialect they chose. 108 Another important finding of this investigation is that speakers often adopt the dialectal characteristics of the mother into their own speech.
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participants also argued that they were able to “switch” dialects, which Potowski and
Matts (2008, p. 156) argue indicates that these particular speakers “consciously used
language to mark either their MX or PR identity in given contexts.”
Although none of the HS who participated in the present investigation were
MexiRican and only two were of mixed parentage, all could possibly be described, to
some extent, as bi-cultural. All of the HS were raised in Spanish-speaking households
and communities, but were also current residents of the United States, attended an
American university, and were fluent (and some even dominant) speakers of English.
These facts lead to the questions 1) could HS of Spanish combine characteristics of
English and Spanish vowels as a means to emphasize their hybrid identity? or 2) could
language dominance, social or familial pressures, and the desire to “fit in” to a particular
social or ethnic group result in their stressing or deemphasizing characteristics of one of
their two languages?
Although the present study intended to examine the connection between identity
and Spanish vowel pronunciation by means of the language background questionnaire,
methodological difficulties prevented the analysis. The background questionnaire
included a series of questions which asked the participants to indicate which ethnic terms
they would use to self-identify, as well as statements about how strongly they felt
speaking Spanish helped them feel connected with their heritage. Nearly all participants
indicated that they identified as latino/as, mexicano/as, and americano/as. In addition,
they all indicated that they either “agreed” or “strongly agreed” with the statement
“Speaking Spanish helps me feel connected with my heritage.” There was thus very little
variability within the group of participants in terms of how they responded to these items
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on the background questionnaire. Future investigations could incorporate more detailed
and open-ended questions in order to further explore the connection between HS
language use, pronunciation, and identity. A larger subject population and more carefully
designed instruments may reveal that HS identity is linked to the pronunciation of their
vowels in Spanish.
5.5.3 Control data
The goal of the present study was first and foremost, to describe HS vowel
pronunciation in a systematic way by assessing the extent to which linguistic variables,
speech style, and individual characteristics known to affect monolingual and L2 learner
varieties also affect HS speech production. Although this study does provide a
comprehensive acoustic examination of HS vowels, several important questions about HS
speech production cannot be addressed in this dissertation due to the lack of control data.
One of the primary arguments in the heritage literature is that HS exhibit a “benefit” in
the domain of pronunciation due to their early exposure to Spanish, resulting in their
sounding more native-like when compared to L2 learners who acquired the language later
in life. Comparisons between HS vowels and monolingual Spanish vowel pronunciation
obtained in other studies offered some insight into which characteristics HS share with
native monolinguals and how they differ, but comparing across studies is less than ideal.
As studies employ different instruments and analysis techniques, the comparisons
between two separate investigations are often not reliable. In order to truly understand
how “native-like” HS pronunciation is, vowel productions of monolingual Spanish
speakers from a similar dialect region, as well as the pronunciation of late L2 learners of
Spanish, need to be obtained.
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An examination of monolingual Spanish vowels produced in the same tasks
utilized in this dissertation would reveal with greater reliability the characteristics that HS
share with monolinguals as well as how they differ. As few cross-dialectal studies of
Spanish vowels have been conducted, it remains unclear if the HS pronunciations of /e/
and /u/ actually fall within the range of possible productions among monolingual
speakers. In other words, the backed /e/ and fronted /u/ produced by HS may be a
characteristic of monolingual Spanish spoken in central Mexico, and not the result of
English influence as has been suggested throughout this dissertation. Most acoustic
studies of Spanish vowels have examined peninsular varieties (the exceptions being
Servín and Rodríguez (2001), Serrano (2006), and the impressionistic studies carried out
by Matluck (1952), Boyd-Bowman (1952) and Lope Blanch (1972), and therefore little is
known about the vowel system of central Mexico. Thus, obtaining monolingual vowel
productions with the same speech elicitation instruments employed in this dissertation
would not only indicate if the backing of /e/ and fronting of /u/ are present in
monolingual Spanish, but also contribute to the general body of literature pertaining to
Spanish vowels.
In order to understand how early exposure to a language affects HS vowel
production later in life and if HS actually do “benefit” in the domain of pronunciation, a
comparison between HS and late learners of Spanish is also necessary. A number of
investigations have indicated that age of learning and age of arrival to a foreign country
impact pronunciation in the heritage language or the L2 (Chang et al., 2009; Flege et al.,
1995; Godson, 2003, among others). A comparison between Spanish vowels produced
by HS and late L2 learners of Spanish could support previous findings if the HS vowel
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productions were found to more closely resemble the monolingual Spanish vowel
productions than the vowels produced by L2 learners.
Another question that cannot be fully answered based solely on the data obtained
from HS is the extent to which HS have integrated characteristics of English into their
Spanish. In order to understand if and how the heritage Spanish vowel system is
modified or hybridized directly due to English contact, an analysis of the English vowels
produced by the same HS who participated in this study should also be conducted and
compared to the English vowels of monolingual English speakers from the Chicago area.
Such an analysis would allow for three important comparisons. First of all, an analysis of
HS English vowels would allow for an examination of how lexical stress, syllable type,
and speech style affect their non-heritage language, and how the effects of the
aforementioned variables differ across their two languages. Second, comparing HS
English vowels to monolingual English vowels would indicate the extent to which HS
integrate characteristics of the Northern Cities Vowel Shift (NCVS) into their English.
Third, a comparison across languages between HS Spanish vowels and monolingual
English vowels would reveal if HS of Spanish have integrated characteristics of the
NCVS into their Spanish. Although several studies have examined Heritage English
pronunciation in the Northern Cities region (Konopka and Pierrehumbert, 2008, in press;
Roeder, 2010), none of the previous investigations have analyzed if and how the NCVS
in English affects the pronunciation of Spanish vowels.
To summarize this section briefly, analyses and comparisons between
monolingual Spanish, English, and L2 learner vowels would offer additional insight into
the HS vowel system. Comparisons between HS, monolingual Spanish speakers, and
315
advanced late L2 learners would indicate the extent to which HS pronounce Spanish in a
more native-like fashion, and potentially support the argument that early exposure to a
language results in a benefit in pronunciation later in life. An examination of HS English
and monolingual English vowels would reveal if the unique distribution of HS vowels
and the presence of robust stress effects are partly attributable to English influence.
Finally, a cross-language comparison between monolingual English vowels and HS
Spanish vowels might suggest that characteristics of the NCVS have influenced the
Spanish vowel pronunciation of this population of HS of Spanish from Chicago. Taken
together, the additional experiments and comparisons would allow for a more complete
understanding of HS vowel pronunciation and the factors that influence this population’s
productions of Spanish vowels.
5.6 Summary of discussion
This chapter focused on discussing the results of the statistical analyses described
in chapter 4. Section 5.1 described the overall distribution of Spanish vowels, comparing
the HS patterns of pronunciation to native speaker norms described in the literature. The
organization of the HS vowel system differed from traditional descriptions of the
monolingual Spanish vowel system in that it was less symmetrical than typically
described, and exhibited an /e/ that was produced farther back and an /u/ that was
produced farther front than traditional characterizations of monolingual Spanish vowels.
Section 5.2 of this chapter discussed how lexical stress, syllable type, and speech
style affected HS vowel production. The atonic vowels produced by the HS in this study
were more centralized and shorter than the tonic vowels: a pattern that is generally
unattested in monolingual Spanish varieties. As discussed in section 5.2.1, the shortening
316
and centralization could be attributed to HS exhibiting the unstressed vowel reduction
argued to exist in central Mexico, or could be the result of contact with English. Section
5.2.2 focused on discussing the influence of syllable type on HS vowel production.
Overall, the anticipated mid vowel allophony argued to exist for monolingual varieties of
Spanish was not observed in the HS system. The overall lack of a syllable type effect in
HS Spanish could indicate that the differences in vowel production based on syllable
structure are not robust enough to manifest themselves categorically or statistically.
However, the lack of an effect of syllable type on pronunciation could have been due, in
part, to the inclusion of /s/ as the coda consonant in many of the closed syllable examples.
Finally, section 5.2.3 discussed how speech style affected the organization of HS vowels.
Like monolingual speakers of Spanish, HS also exhibited greater degrees of
centralization and duration reduction in spontaneous speech when compared to controlled
speech. The differences in vowel dispersion revealed across the three tasks confirmed
that in order to truly understand the vowel space of a specific group of speakers, it is
important to analyze different speech styles.
A discussion of the effects of the between-subjects variables was presented in
section 5.3. The analysis of the connection between course level and vowel production
revealed that only the /u/ differed statistically between the groups: the advanced-level
participants produced an /u/ that was farther back in the vowel space than the
intermediate-level speakers. Section 5.3.2 discussed the relationship between grammar
proficiency and vowel production. The analyses of the non-normalized formant values
suggested that participants with higher grammar proficiency scores had a tendency to
produce vowels that occupied a smaller portion of the acoustic space than those with
317
lower grammar proficiency scores: a finding that conflicted with the results of Menke
and Face (2010) and Chang et al. (2009). When the analyses were conducted with the
normalized formant values, however, the only vowel to show a significant relationship
with grammar proficiency was /o/. Combined with the results of course level, it was
concluded that HS with more overt language instruction and more formal knowledge of
prescriptive grammar might exhibit a greater separation of the back vowel categories.
However, as traditional grammar proficiency tests are perhaps not the most appropriate
means of examining HS proficiency in Spanish, the results should be interpreted with
caution.
Section 5.3.3 and section 5.3.4 described how traveling abroad and speaking
Spanish outside of the classroom impacted HS vowel production. Those who traveled
abroad more frequently were found to produce the point vowels more peripherally than
those who traveled less frequently. A similar trend for expansion was revealed for
Spanish use. The participants who reported speaking Spanish more often and in a wider
variety of contexts tended to produce the Spanish vowels more peripherally. The trend
for expansion based on travel frequency and Spanish use was interpreted to mean that
traveling and speaking Spanish frequently promote more “native-like” vowel
pronunciation, if “native-ness” refers to expansion of the vowel space. The question of
“native-ness” was discussed further in section 5.4., which described an additional
interaction between vowel, task, and travel. The results of the interaction suggested that
more experienced HS have an expanded vowel space because they have acquired, or are
closer to acquiring, the formal speech style: the most hyperarticulated speech represented
by the controlled speech task (CPT).
318
The findings of the present study also revealed an important connection between
HS and L2 learners. A large body of literature suggests that traveling abroad and
speaking more Spanish outside of the classroom have a positive impact on the acquisition
of L2 pronunciation. That the same behaviors affected HS vowel production suggests
that even HS, who are argued to “sound” like native speakers, may benefit from increased
exposure to Spanish.
Section 5.3.5 discussed the connection between cultural sensitivity and HS vowel
production. Overall, only the vowel /i/ was found to correlate with cultural sensitivity:
the Euclidean distance of the /i/ from the centroid decreased as the cultural sensitivity
score increased. The results of this analysis suggest that, unlike the L2 learners in Alvord
& Christiansen (2009), there was very little connection between HS vowel production
and cultural sensitivity. Section 5.3.5 discussed two possible explanations for the
absence of a connection between cultural sensitivity and vowel production: 1) only the
total cultural sensitivity score was analyzed and not the subscales, and 2) there may not
have been sufficient variability within the total scores to show a consistent effect.
Last of all, this chapter discussed some of the limitations of the present
investigation and suggested directions for future research. One of the limitations of this
study was difficulty in creating phonetically balanced instruments (i.e., PIT and CPT that
could be performed by HS of Spanish). A second limitation was the inability to directly
examine the connection between HS language use and identity with the language
background questionnaire utilized in this study. Finally, as there were no control groups
included in this dissertation, the question of how “native-like” HS pronunciation really is
cannot be fully addressed until native monolingual vowel productions in multiple speech
319
styles are analyzed. In the future, additional studies of HS and monolingual Spanish
vowels may consider balancing the corpora by consonantal context and lexical frequency,
as well as integrating additional instruments that can more accurately address the
connection between language use and identity.
320
6 CONCLUSIONS
The present investigation has offered the first acoustic characterization of the HS
Spanish vowel system by systematically measuring the F1 and F2 frequencies and
duration, calculating a centroid and the Euclidean distance of vowels from the centroid,
and analyzing these measures statistically. The analyses examined the effects of several
variables on HS vowel production, indicating that both language internal and language
external factors play an important role in how HS of Spanish pronounce their vowels.
To summarize the general findings of this dissertation, HS exhibited robust
differences in vowel quality, dispersion, and duration based on lexical stress: atonic
vowels were produced in a more central location within the vowel space, were situated
closer to the centroid, and were shorter in duration than their tonic counterparts. The
effects of speech style on vowel production were similar to those described for lexical
stress, in that vowels were more centralized and shorter in spontaneous speech styles
when compared to vowels produced in controlled styles. The effects of syllable type
were less clear and robust, suggesting that the mid vowel allophony argued to exist in
monolingual Spanish vowel systems is not present in the HS system.
Extralinguistic influences such as Spanish use and travel frequency were found to
have the greatest effect on pronunciation. Heritage speakers who reported traveling more
and speaking Spanish more regularly were found to produce vowels that were more
peripheral than those produced by infrequent travelers and speakers of Spanish. The
expansion of the vowel space suggests a closer approximation to the native speaker
vowel configuration reported in other studies. Course level and grammar proficiency had
some effects on HS vowel pronunciation and also suggested an expansion effect for more
321
advanced HS and those with higher proficiency scores, but the effects were primarily
limited to the back vowels. Cultural sensitivity had the least robust effects on
pronunciation, indicating that at least for this group of HS, cultural sensitivity does not
play an integral role in shaping vowel pronunciation.
Taken together, the overall findings of this dissertation have important implications
for our understanding of Spanish vowel systems, the HS Spanish vowel system, and the
complex interplay of factors that influence HS pronunciation. First and foremost, this
investigation contributes to the growing number of acoustic studies of Spanish vowels.
The general description of the HS vowel space provided further evidence against a
simple, stable, symmetrical, five-vowel system typically argued for Spanish. Although
the HS in this study are bilingual and therefore the distribution and organization of their
vowels could be influenced by language contact, the examination of HS vowels indicates
that Spanish vowels can vary from the established norms and still potentially be
perceived as “native-sounding.” In addition, the description of the vowel space indicated
how vowel productions can vary within the acoustic space, on which dimensions they
exhibited greater or lesser variation, and which vowels showed the greatest degree of
overlap. Understanding the distribution of HS Spanish vowels and the dimensions on
which they vary and overlap may help establish the possible acoustic ranges that Spanish
vowels can occupy.
The effects (or lack thereof) of lexical stress, speech style, and syllable type also
have implications for how the Spanish vowel system is described and analyzed in future
studies. That atonic vowels reduced in HS Spanish, but not in the direction of schwa,
may suggest that 1) Spanish vowels exhibit more quality and quantity differences based
322
on lexical stress than previously believed, and 2) the way that lexical stress effects
manifest themselves in Spanish differs from what is observed in English. The analysis of
syllable type lends more evidence against the argument that the Spanish mid vowels
exhibit allophonic variation: an assumption that had been questioned and partially
disproven by Morrison (2004) and Servín and Rodríguez (2001). Instead of arguing for
distinct allophones for the mid vowels, future descriptions of the system might emphasize
that small differences in pronunciation may result as a consequence of coarticulatory
effects or gestural timing based on the surrounding consonantal context. Finally, an
examination of HS vowel quality and duration in the three different tasks confirmed the
influence of stylistic effects on vowel pronunciation. The similar effects observed for
both HS and monolingual speaker populations indicate that in order to truly understand
the Spanish vowel system, it is important to analyze pronunciation in multiple speech
styles and on multiple levels, and not base descriptions of the system on controlled
utterances alone.
Combined, the statistical analyses carried out in this dissertation offer insight into
which characteristics HS share with monolingual speakers of Spanish, and provide
further support for a modified system of pronunciation for bilingual speakers. Like
monolingual speakers of Spanish, HS exhibited vowel quality and quantity reduction in
spontaneous speech, as well as the intrinsic vowel duration described by Marín Gálvez
(1995). In addition, they patterned with the monolingual speakers of Morrison (2004)
and Servín and Rodríguez (2001) in that they did not produce the Spanish mid vowels
differently in closed and open syllables. Despite the similarities, however, HS vowels
differ from traditional descriptions of monolingual Spanish vowels in several important
323
ways. In contrast to what has traditionally been described for Spanish, the HS vowel
space is asymmetrical and is characterized by five degrees of height and four degrees of
backness. In addition, the position of the /e/ and /u/ in the acoustic space differed from
presupposed monolingual productions in that /e/ was produced further back and lower in
the space, and the /u/ was significantly fronted. Finally, the degree of unstressed vowel
reduction exhibited by HS is unattested in monolingual varieties, although the absence of
a stress effect has been mostly assumed for Mexican varieties of Spanish and not
thoroughly acoustically examined.
Thus, although HS of Spanish are typically argued to produce Spanish sounds in a
native-like way, the present study indicates that their productions are not identical to
those of a monolingual, or at least not to previous descriptions of monolingual Spanish
vowels; their system is modified, sharing some characteristics with monolingual varieties
but differing on other dimensions. This first acoustic analysis of HS vowels therefore
lays the foundation for future comparisons to monolingual Mexican Spanish vowels
using the same speech elicitation instruments employed here. In-depth comparisons with
monolingual Mexican age-matched peers will provide further insight into the similarity
between HS and monolingual vowel production.
Another important aspect of this dissertation is that it has revealed additional
similarities between HS and L2 learners in terms of which individual behaviors and
practices impact speech production. The same behaviors argued to have a positive impact
on HS and L2 morphosyntactic performance and on L2 acquisition of pronunciation were
also found to influence HS pronunciation. That is, although HS are argued to “sound”
like native speakers, behaviors that are typically encouraged for L2 learners to acquire the
324
language were found to impact HS vowel production. Traveling abroad resulted in a
greater expansion of the acoustic space, as did speaking Spanish outside of the classroom
more frequently. In addition, there is some suggestion that formal grammatical
knowledge and instruction can also alter the way that HS produce their vowels even
though the effects of grammar proficiency and course level reported in this investigation
were less robust than those obtained for travel and Spanish use.
The finding that extralinguistic factors influence HS pronunciation contributes to
our general understanding of HS populations and has important implications for how HS
are described in the literature. That traveling abroad and more Spanish use, two
behaviors known to facilitate L2 acquisition of pronunciation, also affect HS production
of vowels suggests that there may be more similarities between HS and learners than
previously believed. Investigations focusing on morphosyntactic knowledge and
pedagogical needs have already indicated that HS and L2 learners exhibit similar
behaviors in both domains, and that traveling abroad, formal language instruction, and
Spanish use outside of the classroom are three factors that correlate with morpho-
syntactic knowledge. The assumption present in the literature, however, is that HS
pronunciation is already superior to, or more native-like than, that of L2 learners at
similar levels of proficiency. The results of this dissertation lend evidence to the
variability of HS vowel categories: just like L2 learners, HS pronunciation may be
shaped by a number of language- external influences.
The effect of extralinguistic influences on vowel production also confirms that
seemingly homogenous populations may exhibit considerable variability in
pronunciation, and that small changes in behavior can have a significant impact on
325
speech production. Although all of the HS who participated in this study had similar
backgrounds, their pronunciation of vowels was not identical and was affected by
multiple factors. The morphosyntactic and pedagogical literature has already recognized
the wide-range of variation in HS abilities, but variation in HS pronunciation has received
little attention. Thus, future descriptions of HS should recognize the variability not only
in proficiency level, but also in pronunciation, and not assume that all HS “benefit” from
early exposure to Spanish in the same way.
In conclusion, the acoustic and statistical analyses presented in this study have
contributed to our overall understanding of the Spanish vowel system, and have provided
the first comprehensive description of HS vowels. Taken together, the findings depict
HS of Spanish as a unique population of bilingual individuals who, although often
equated with native speakers in terms of their pronunciation, exhibit a distinct
organization of vowels that is influenced by a complex interaction of linguistic, stylistic,
and extralinguistic factors. All in all, this investigation emphasizes the importance of
acoustic analyses of pronunciation and demonstrates how detailed, acoustic studies of
speech production can offer insight into the system that is not achievable by impressions
alone.
326
REFERENCES
Adank, P., Smits, R., & van Hout, R. (2004). A comparison of vowel normalization
procedures for language variation research. The Journal of the Acoustical Society
of America, 116(5), 3099-3107.
Alvord, S., & Christiansen, D. (2009). Acquisition of spirantization of voiced stops
during anextended stay abroad. Paper presented at the 9th Hispanic Linguistics
Symposium 21-24 of October, 2009. Universidad de Puerto Rico, Río Piedras,
Puerto Rico.
Alvord, S., & Rogers, B. (2011). Vowel quality and language contact in Miami-Cuban
Spanish. Paper presented at The 2011 Hispanic Linguistic Symposium 6-9 of
October, 2011. University of Georgia, Athens, GA.
Amastae, J. (1978). The Acquisition of English Vowels. Papers in Linguistics, 11(3-4),
423-457.
Amastae, J. (1982). Mid vowel raising and its consequences in Spanish. Linguistics, 20,
157-202.
Amengual, M. (2011). Spanish and Catalan in Majorca: Are there contact-induced
changes in the Catalan vowel system? In L. A. Ortiz-López (Ed.), Selected
Proceedings of the 13th Hispanic Linguistics Symposium (pp. 214-223).
Somerville, MA: Cascadilla Proceedings Project.
Au, T. K., Knightly, L. M., Jun, S.-A., & Oh, J. S. (2002). Overhearing a language during
childhood. Psychological Science, 13, 238–243.
Au, T.K., Oh, J.S., Knightly, L.M., Jun, S-A., & Romo, L. (2008). Salvaging a childhood
language. Journal of Memory and Language, 58, 998-1011.
327
Boersma, P., & Weenink, D. (2010). Praat: doing phonetics by computer [Computer
program]. Version 5.1.44, retrieved 4 October 2010 from http://www.praat.org/
Bolger, P., & Zapata, G. (2011). Psycholinguistic Approaches to Language Processing in
Heritage Speakers. The Heritage Language Journal, 8(1), 1-29.
Boomershine, A. (2011). The perception of English vowel contrasts: The case of
Monolingual, Bilingual, and Heritage Speakers of Spanish and English. Paper
presented at The 2011 Hispanic Linguistic Symposium 6-9 of October, 2011.
University of Georgia, Athens, GA.
Boyd-Bowman, P. (1952). La pérdida de vocales átonas en la altiplanicie Mexicana.
Nueva Revista de Filología Hispánica, 6(2), 138-140.
Bradlow, A. (1994). A comparative acoustic study of English and Spanish vowels. JASA,
97(3), 1916-1924.
Bullock, B. E. (2009). Prosody in contact in French: A case study from a heritage variety
in the USA. International Journal of Bilingualism, 13(2), 165–194.
Bybee, J. (2001). Phonology and language use. Cambridge,U.K.: Cambridge University
Press.
Carter, P. (2007). Phonetic variation and speaker agency: Mexicana identity in a North
Carolina Middle school. University of Pennsylvania Working Papers in
Linguistics, 13(2), 1-14.
Chang, C., Haynes, E., Yao, Y., & Rhodes, R. (2009). The Phonetic Space of
Phonological Categories in Heritage Speakers of Mandarin. In M. Elliott et al.
(Eds.), Proceedings from the 43rd Annual Meeting of the Chicago Linguistic
Society: The Main Session, 31-45. Chicago, IL: Chicago Linguistic Society.
328
Christiansen, D. (2009). Acquisition of spirantization of voiced stops during an
extended stay abroad. Master’s Thesis, Brigham Young University.
Clopper, C., Pisoni, D., & de Jong, K. (2005). Acoustic characteristics of the vowel
systems of six regional varieties of American English. Journal of the Acoustical
Society of America, 118 (3), 1661-1676.
Cushner, K. (1986). The Inventory of Cross-Cultural Sensitivity. Kent State University:
School of Education.
Delattre, P. (1969). An acoustic and articulatory study of vowel reduction in four
languages. International Review of Applied Linguistics in Language Teaching,
7(4), 295-325.
Delforge, A. (2008). Unstressed vowel reduction in Andean Spanish. In L. Colantoni & J.
Steele (Eds.), Selected Proceedings of the 3rd Conference on Laboratory
Approaches to Spanish Phonology (pp.107-124). Somerville, MA: Cascadilla
Proceedings Project.
Díaz-Campos, M. (2004). Context of learning of Spanish second language phonology.
Studies in Second Language Acquisition, 26, 249-273.
Díaz-Campos, Manuel. (2006). The effect of style in second language phonology: an
analysis of segmental acquisition in study abroad and regular-classroom students.
In C. Klee & T. Face (Eds.), Selected Proceedings of the 7th Conference on the
Acquisition of Spanish and Portuguese as First and Second Languages (pp. 26-
39). Somerville, MA: Cascadilla Proceedings Project.
329
Duprey-Almeyda, M. (2009). Language use, attitudes, perception and production of
English vowels among tenth graders in a public high school in Aguadilla, Puerto
Rico. University of Puerto Rico: Mayaguez, Puerto Rico.
Flege, J. (1991). Age of learning affects the authenticity of voice-onset time (VOT) in
stop consonants produced in a second language. Journal of the Acoustical Society
of America, 89(1), 395-411.
Flege, J. & Eefting, W. (1987). The production and perception of English stops by
Spanish speakers of English. Journal of Phonetics, 15, 67-83.
Flege, J. & Eefting, W. (1988). Imitation of a VOT continuum by native speakers of
English and Spanish; Evidence for phonetic category formation. Journal of the
Acoustical Society of America, 83(2), 729-740.
Flege, J., Munro, M., & MacKay, I. (1995). Factors affecting degree of perceived foreign
accent in a second language. Journal of the Acoustical Society of America, 97,
3125-3134.
Fought, C. (1999) A majority sound change in a minority community: /u/-fronting in
Chicano English. Journal of Sociolinguistics, 3, 5-23.
Geeslin, K. & Gudmestad, A. (2010). An exploration of the range and frequency of
occurrence of forms in potentially-variable structures in second language Spanish.
Studies in Second Language Acquisition, 32(3), 433-463.
Godinez, M. & Maddieson, I. (1985). Vowel differences between Chicano and general
Californian English? International Journal of the Sociology of Language,
43-58.
330
Godson, L. (2003). Phonetics of Language Attrition: Vowel Production and Articulatory
Setting in the Speech of Western Armenian Heritage Speakers. Doctoral
dissertation, University of California, San Diego.
Goldstein, U. (1980) An articulatory model for the vocal tracts of growing children.
Doctoral dissertation ,M . I . T .
Grabe, E., & Low, E. (2002). Durational variability in speech and the rhythm class
hypothesis. In C. Gussenhoven & N. Warner (Eds.), Papers in Laboratory
Phonology 7 (pp. 515-546). Berlin: Mouton de Gruyter.
Guirao, M., & Borzone de Manrique, A. (1975). Identification of Argentine Spanish
vowels. Journal of Psycholinguistic Research, 4(1), 17-25.
Guion, Susan G. (2003). The vowel systems of Quichua-Spanish bilinguals. Phonetica,
60, 98-128.
Harmegnies, B., & Poch-Olivé, D. (1992). A study of style-induced vowel variability:
Laboratory versus spontaneous speech in Spanish. Speech Communication, 11(4-
5), 429-437.
Harris, M., & Gries, S. (2011). Measures of speech rhythm and the role of corpus-based
word frequency: a multifactorial comparison of Spanish(-English) speakers.
International Journal of English Studies, 11(2), 1-22.
Henríquez Ureña, P. (1938). El español en Méjico, los Estados Unidos y la América
Central. Buenos Aires: Biblioteca de Dialectología Hispanoamericana 4.
Hillenbrand, J., Getty, L., Clark, M., & Wheeler, K. (1995). Acoustic characteristics of
American English vowels. Journal of the Acoustical Society of America, 97,
3099-3111.
331
House, A. & Fairbanks, G. (1953). The influence of consonant environment upon the
secondary acoustical characteristics of vowels. In N. Lass, (Ed.), UC Berkeley
Phonology Lab Annual Report (2011) (pp. 79-99).
Hualde, J.I. (2005). The Sounds of Spanish. Cambridge: Cambridge University Press.
Johnson, K. (2003). Acoustic and Auditory Phonetics. Malden: Blackwell.
Jurado, M., & Arenas, M. (2005). La fonética del español: Análisis e investigación de
los sonidos del habla. Buenos Aires: Editorial Quorum.
Kagan, O. (2005). In support of a proficiency-based definition of Heritage Language
learners: The Case of Russian. The International Journal of Bilingual Education
and Bilingualism, 8(2-3), 213-221.
Knightly, L., Jun, S.A., Oh, J., & Au, T. (2003). Production benefits of childhood
overhearing. Journal of the Acoustical Society of America, 114(1), 465-474.
Koenig, W., Dunn, H. K., & Lacey, L. Y. (1946). The sound spectrograph. Journal of the
Acoustical Society of America, 18, 19-49.
Konopka, K. & Pierrehumbert J.B. (in press). Vowel dynamics of Mexican Heritage
English: Language contact and phonetic change in a Chicago community. Papers
from the 46th Annual Meeting of the Chicago Linguistic Society.
Konopka, K. & Pierrehumbert, J.B. (2008) Vowels in Contact: Mexican Heritage English
in Chicago. SALSA, 10, 94-104.
Labov, W. (1972). Sociolinguistic Patterns. Philadelphia: University of Pennsylvania
Press.
Labov, W., Ash, S., & Boberg, C. (2006). Atlas of North American English. New York:
Mouton de Gruyter.
332
Lafford, B. (2006). The effects of study abroad vs. classroom contexts on Spanish SLA:
Old assumptions, new insights and future research directions. In C. A. Klee & T.
L. Face (Eds.), Selected proceedings of the 7th Conference on the Acquisition of
Spanish and Portuguese as First and Second Languages (pp. 1-25). Somerville,
MA: Cascadilla Proceedings Project.
Ladefoged, P. (1980). What are linguistic sounds made of? Language, 56 (3), 485-502.
Ladefoged, P. (2001). A course in phonetics (4th ed.). Boston: Thomson.
Ladefoged, P. (2003). Phonetic data analysis. Malden: Blackwell.
Ladefoged, P. (2005). Vowels and consonants (2nd ed.). Malden: Blackwell.
Lennes, M. (2002). Calculate_segment_durations.praat. http://www.helsinki.fi/
~lennes/praat-scripts/ (15 October 2010).
Lennes, M. (2003). Collect_formant_data_from_files.praat. http://www.helsinki.fi/
~lennes /praat-scripts/ (15 October 2010).
Lindblom, B. (1990). Explaining Phonetic Variation: a Sketch of the H&H Theory. In H.
J. Hardcastle & A. Marchal (Eds.), Speech Production and Speech Modeling,
NATO ASI Series D: Behavioural and Social Sciences (Vol. 55, pp. 403–439).
Dordrecht: Kluwer.
Lipski, J.M. (1994). Latin American Spanish. London: Longman.
Lipski, J.M. (2008). Varieties of Spanish in the United States. Washington, D.C.:
Georgetown University Press.
Lope Blanch, J. (1972). En torno a las vocales caedizas del español mexicano. Estudios
sobre el español de México. México: Editorial Universidad Nacional Autónoma
de México.
333
Lobanov, B.M. (1971). Classification of Russian vowels spoken by different listeners.
Journal of the Acoustical Society of America, 49, 606-08.
Luce, P., & Pisoni, D. (1998). Recognizing spoken words: The neighborhood activation
model. Ear and Hearing, 19 (1), 1–36.
Lynch, A. (2003). The Relationship between Second and Heritage Language
Acquisition:Notes on Research and Theory Building. The Heritage Language
Journal, 1(1), 1-18.
Malovrh, P. (2008). A multifaceted analysis of the interlanguage development of
Spanish direct-object clitic pronouns observed in L2-learner production. Doctoral
Dissertation, Indiana University, Bloomington.
Marín Gálvez, R. (1995). La duración vocálica en español. E.L.U.A., 10, 213-226.
Martín Butragueño, P. (2011). Vocales en contexto. In El homenaje a Thomas C. Smith-
Stark. Mexico: Colegio de Mexico.
Martínez-Celdrán, E. (1984). Cantidad e intensidad en los sonidos obstruyentes del
castellano: Hacia una caracterización acústica de los sonidos aproximantes.
Estudios de fonética experimental, 1, 73–129.
Martínez-Celdrán, E. (1995). En torno a las vocales del español. En torno a las vocales
del español: análisis y reconocimiento. Estudios de Fonética Experimental, VII,
PPU, 195-218.
Matluck, J. (1952). La pronunciación del español en el valle de México. Nueva Revista
de Filología Hispánica, 6(2), 109-120.
Mendoza-Denton, N. (1999). Sociolinguistics and linguistic anthropology of US Latinos.
Annual Review of Anthropology, 28, 375-379.
334
Menke, M., & Face, T. (2010). Second language Spanish vowel production: An acoustic
Analysis. Studies in Hispanic and Lusophone Linguistics, 3(1), 181-214.
Mikulski, A. (2010). Age of onset of bilingualism, language use, and the volitional
subjunctive in heritage learners of Spanish. Heritage Language Journal, 7(1), 28-
45.
Montrul, S. (2005). Second language acquisition and first language loss in adult early
bilinguals: exploring some differences and similarities. Second Language
Research, 2(3), 199–249.
Montrul, S. & Bowles, M. (2010). Is Grammar Instruction Beneficial for Heritage
Language Learners? Dative Case Marking in Spanish. Heritage Language
Journal, 7(1), 47-73.
Montrul, S., Foote, R., & Perpiñan, S. (2008a). Gender Agreement in Adult Second
Language Learners and Spanish HeritageSpeakers: The Effects of Age and
Contextof Acquisition. Language Learning, 58(3), 503–553.
Montrul, S., Foote, R., & Perpiñán, S. (2008b). Knowledge of Wh-movement in Spanish
L2 Learners and Heritage speakers. In J. Bruhn de Garavito & E. Valenzuela
(Eds.), Selected Proceedings of the 10th Hispanic Linguistics Symposium (pp. 93-
106). Somerville, MA: Cascadilla Proceedings Project.
Morrison, G. (2004). An acoustic and statistical analysis of Spanish mid-vowel
allophones. Estudios de Fonética Experimental, 13, 11-37.
Morrison, G., & Escudero, P. (2007). A cross-dialect comparison of Peninsular- and
Peruvian-Spanish vowels. Proceedings of the 16th International Congress of
Phonetic Sciences: Saarbrücken 2007.
335
Mrak, A. (2011). Heritage speakers and the Standard: Fighting linguistic hegemony. In
L. Ortiz-López (Ed.), Selected Proceedings of the 13th Hispanic Linguistics
Symposium (pp. 161-168). Somerville, MA: Cascadilla Proceedings Project.
Munson, B., & Solomon, N. (2004). The effect of phonological neighborhood density on
vowel articulation. Journal of Speech, Language, and Hearing Research, 47,
1048–1058.
Munro, M., Flege, J., & MacKay, I. (1996). The effect of age of second-language
learning on the production of English vowels. Applied Psycholinguistics, 17, 313-
334.
Navarro Tomás, T. (1918). Manual de pronunciación español (12th ed.). Madrid, Spain:
CSIC.
Navarro Tomás, Tomás. (1917). Cantidad de las vocales inacentuadas. Revista de
Filología Española, 4, 371–388.
Oh, J. S., Jun, S.-A., Knightly, L. M., & Au, T. K. (2003). Holding on to childhood
language memory. Cognition, 86, B53–B64.
O’Rourke, E. (2010). Dialect differences and the bilingual vowel space in Peruvian
Spanish. In O. Ortega-Llebaria (Ed.), Selected Proceedings of the 4th Conference
on Laboratory Approaches to Spanish Phonology (pp. 20-30). Somerville, MA:
Cascadilla Proceedings Project.
Peterson, G.E., & Barney, H.L., (1952). Control methods used in a study of the vowels.
Journal of the Acoustical Society of America, 24, 175-184.
Perrisinotto, G. (1975). Fonología del español hablado en la Ciudad de México. Ensayo
de un método sociolingüístico. México: El Colegio de México.
336
Poch-Olive, D., Harmegnies, B.,& Butragueño, P. (2008). Influencia del estilo de habla
sobre las características de las realizaciones vocálicas en el español de la ciudad
de México. Actas del XV Congreso Internacional ALFAL. Montevideo,
Uruguay, 18-21 de agosto de 2008, CD.
Pike, K. (1945). The intonation of American English. Ann Arbor: University of Michigan
Press.
Potowski, K. (in press). Identity and heritage languages: Moving beyond essentializations. In
S. Beaudrie & M. Fairclough (Eds.), Spanish as a heritage language in the U.S.:
State of the science. Washington, DC: Georgetown University Press.
Potowski, K., & Matts, J. (2008). MexiRicans: Interethnic Language and Identity.
Journal of Language, Identity, and Education, 7, 137–160.
Potowski, K., Potowski, Jegerski, J., & Morgan-Short, K. (2009). The effects of
instruction on linguistic development in Spanish heritage language speakers.
Language Learning, 59 (3), 537-579.
Prieto, P., Mar Vanrell, M., Astruc, L., Payne, E., Brechtje, P. (In Press). Phonotactic
and phrasal properties of speech rhythm: Evidence from Catalan, English, and
Spanish. Speech Communication. doi: 10.1016/j.specom.2011.12.001.
Quilis, A., & Esgueva, M. (1983). Realización de los fonemas vocálicos españoles en
posición fonética normal. In M. Esgueva & M. Cantarero (Eds.), Estudios de
fonética (pp. 159-251). Madrid: Consejo Superior de Investigaciones Científicas.
Roeder, R. (2010). Effects of consonantal context on the pronunciation of /æ/ in the
English of speakers of Mexican heritage from south central Michigan. In N.
Niedzielski and D. Preston (Eds.), Studies in Sociophonetics (pp. 71-89). Mouton
de Gruyter.
337
Rosner, B., & Pickering, J. (1994). Vowel perception and production. Oxford: Oxford
University Press.
Rothman, J. (2007). Heritage speaker competence differences, language change, and
input type: Inflected infinitives in Heritage Brazilian Portuguese. International
Journal of Bilingualism, 11(4), 359-389.
Sadowsky, S. (2010). Los alófonos vocálicos como marcadores de identidad
sociocultural en el discurso oral del castellano de Chile. VI Encuentro Nacional
de Estudios del Discurso Santiago, Chile – 27 y 28 de septiembre de 2010.
Savy, R., & Cutugno, F. (1998). Hypospeech, vowel reduction, and centralization: how
do they interact? Proceedings of the XVIth International Congress of Linguistics.
Schmidt, L., & Willis, E. Systematic Investigation of Voicing Assimilation of Spanish /s/
in Mexico City. In S. Alvord (Ed.), Selected Proceedings of the 5th Conference
on Laboratory Approaches to Romance Phonology (pp. 1-20). Somerville, MA:
Cascadilla Proceedings Project.
Serrano, J. (2006). En torno a las vocales caedizas del español mexicano: una
aproximación sociolingüística. Líderes lingüísticos. México: El Colegio de
México.
Servín, E., & Rodríguez, M. (2001). Estrcutura formántica de las vocales del español de
la ciudad de México. In E. Herrera (Ed.), Temas de fonética instrumental (pp.
39-58). México, D.F.: El Colegio de México, Centro de Estudios Lingüísticos y
Literarios.
Simões, A. (1996). Phonetics in second language acquisition: An acoustic study of
fluency in adult learners of Spanish. Hispania, 79(1), 87–95.
338
Skelton, R B. (1969). The pattern of Spanish vowel sounds. International Review of
AppliedLinguistics in Language Teaching, 7, 231-237.
Stevens, J. (2011). Vowel duration in second language Spanish vowels: Study abroad
versus at-home learners. Arizona Working Papers in SLA & Teaching, 18, 77-104.
Stevens, K. N., & House, A. S. (1963). Perturbation of vowel articulations by
consonantal context: An acoustical study. Journal of Speech and Hearing
Research, 6, 111–128.
Thomas, E.R. (2001). An Acoustic Analysis of Vowel Variation in New World English.
Publication of the American Dialect Society 85. Durham, NC: Duke University
Press.
Thomas, E. R. (2011). Sociophonetics: An Introduction. Basingstoke, England: Palgrave
Macmillan.
Thomas, E.R. & Kendall, T. 2007. NORM: The vowel normalization and plotting suite. [
Online Resource: http://ncslaap.lib.ncsu.edu/tools/norm/ ]
Valdés, G. (2005). Bilingualism, heritage language learners, and SLA research:
Opportunities lost or seized? The Modern Language Journal, 89(3), 410-426.
Valdés, G., and Geoffrion-Vinci, M. (1998). Chicano Spanish: The Problem of the
'Underdeveloped' Code in Bilingual Repertories. The Modern Language Journal,
82, 473-501.
Vitevitch, M., & Stamer, M. (2006). The curious case of competition in Spanish speech
production. Language and Cognitive Processes, 21(6), 760–770.
339
Vitevitch, M., & Stamer, M. (2009). The influence of neighborhood density (and
neighborhood frequency) in spanish speech production: A follow-up report. In
Spoken Language Laboratory Technical Report, Volume 1, pp. 1–6. University of
Kansas.
Watt, D., & Fabricius, A. (2002). Evaluation of a technique for improving the mapping
of multiple speakers' vowel spaces in the F1 ~ F2 plane. In D. Nelson (Ed.), Leeds
Working Papers in Linguistics and Phonetics 9 (pp. 159-73).
Willis, E. (2005). An Initial Examination of Southwest Spanish Vowels. Southwest
Journal of Lingusitics, 24, 185-198.
Willis, E. (2008). No se comen, pero sí se mascan: Variación de las vocales plenas en la
República Dominicana. Actas del XV Congreso Internacional de la Asociación
de Lingüística y Filología de AméricaLatina (ALFAL). Montevideo, Uruguay,
August 18-21, 2008. 6pp.
Yao, Y. (2011). The effects of phonological neighborhoods on pronunciation variation
in conversational speech. Doctoral Dissertation, University of California,
Berkley.
Yavas, M. (1996). Differences in voice onset time in early and later Spanish-English
bilinguals. In A. Roca & J. Jensen (Eds.), Spanish in Contact (pp. 131-141).
Sommerville, MA: Cascadilla Press.
Zampini, M., & Green, K. (2001). The voicing contrast in English and Spanish: The
relationship between perception and production. In J. L. Nicol (Ed.), One Mind,
Two Languages: Bilingual Language Processing (pp. 23-48). Oxford: Blackwell
Publishers.
340
Appendix A: List of words presented in the picture identification task (PIT)
Vowel Syllable type Tonic Atonic
A open lápiz, pescado, llaves, taza, cucharas paquetes, café, avispas,
espaguetis, avestruz, mariscos, tostador
closed máscaras, cáscaras, durazno, tanque sandía, bacteria, pasteles,
langostas
E open espaguetis, bacteria, pasteles, peces, eskeletos, espejos, panqueques
películas, lechugas, revistas, pelota, eskeletos
closed bistéc, insectos, césped pescado, espaguetis, espejos,
escobas, eskeletos
I open películas, cursiva, cuchillos, piscinas, oxígeno piscinas, bicicleta, chicharrones
closed avispas, revistas, mariscos bistéc, insectos, cristal
O open chicharrones, osos, escobas fotografías, autobúses
closed langostas, ostras, tostador tostador, oxígeno
U open lechugas, luces, uvas, estufa, pelota, burbujas, autobúses
cuchillos, cucharas, judías verdes
closed fútbol, avestruz cursiva, durazno, burbujas
341
Appendix B: List of words presented in the carrier phrase task (CPT)
Vowel Syllable type Tonic Atonic
A open mano, masa, caso, paco, papa, paso, pata, codazo, taco, tapa, taza, papaya
closed pasto, atlas atleta
E open mesa, atleta, pecho, pepe, peso, quepo, queso, sistema, techo equipo
closed peste eclipse
I open misa, pico, pipa, piso, pupila, quiso, quito, tico, tipo, tiza, tiburón
closed Eclipse, equipo, pista sistema
O open coco, copa, cosa, mono, mozo, pozo, toco, toso codazo
closed poste conduzco, costumbre, oscura
U open cupo, cuscurro, oscura, puso, sutura pupila, sutura
closed conduzco, costumbre, susto cuscurro
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Appendix C: Language Background questionnaire Participant Background questionnaire
Gender: M F
Date of birth : __________ Current age: _______
Where did your mother live until age 14? ______________________
Where did your father live until age 14? ______________________
In what country were you born? ____________________________
What do you consider to be your native language? ______________________________
Do you speak another language(s) fluently other than your native language? __________
Please list the countries and states in which you have lived in the last 10 years. If you need more space, please continue on the back of this page. If you do not wish to list the specific location, you may leave this blank.
Number of years spent
Ages spent City, State, Country
1.
2.
3.
4.
Please list any foreign languages you have studied, the duration for which they were studied, and rate your abilities in each language. If you need more space, please continue on the back of this page.
Language Ages, years, and place studied
Abilities
1. Listening: good fair poor Reading: good fair poor Speaking: good fair poor
2. Listening: good fair poor
343
Reading: good fair poor Speaking: good fair poor
3. Listening: good fair poor Reading: good fair poor Speaking: good fair poor
Please rate the frequency with which you complete the following activities in ENGLISH.
Activity Daily Weekly Monthly Every few months
(Almost) Never
Speak with friends
●
●
●
● ●
Speak with family
● ● ●
● ●
Watch television ● ● ●
● ●
Read books or magazines
● ● ●
● ●
Listen to the radio or music
● ● ●
● ●
Watch movies ● ● ●
● ●
At the workplace ● ● ●
● ●
At school/ in class
● ● ●
● ●
Please rate the frequency with which you complete the following activities in SPANISH.
Activity Daily Weekly Monthly Every few months
(Almost) Never
Speak with friends
●
●
●
● ●
Speak with family
● ● ●
● ●
Watch television ● ● ●
● ●
Read books or magazines
● ● ●
● ●
Listen to the radio or music
● ● ●
● ●
344
Watch movies ● ● ●
● ●
At the workplace ● ● ●
● ●
At school/ in class
● ● ●
● ●
Please respond to the following questions. If there is a question you do not wish to answer, you may leave this part blank.
Do you ever travel abroad to visit family or friends in a Spanish-speaking country? If so, which countries to you visit, and how often to you travel there?
__________________________________________________________________
__________________________________________________________________
How comfortable do you feel speaking English? Do you feel as though you have any difficulties with the language?
__________________________________________________________________
__________________________________________________________________
How comfortable do you feel speaking Spanish? Do you feel as though you have any difficulties with the language?
__________________________________________________________________
__________________________________________________________________
345
Please rate on a scale of 1-5 (one being STRONGLY DISAGREE, 5 being STRONGLY AGREE) your feelings about the following statements.
STRONGLY DISAGREE
1
AGREE
2
NO OPINION
3
DISAGREE
4
STRONGLY AGREE
5 I like speaking Spanish because it feels natural.
● ● ● ● ●
It is NOT difficult for me to UNDERSTAND Spanish.
● ● ● ● ●
I like speaking English because it feels natural.
● ● ● ● ●
It is NOT difficult for me to UNDERSTAND English.
● ● ● ● ●
I read a lot of books and magazines in Spanish.
● ● ● ● ●
I read a lot of books and magazines in English.
● ● ● ● ●
I understand Spanish grammar well.
● ● ● ● ●
I wish I spoke more Spanish at home and with friends.
● ● ● ● ●
I understand English grammar well.
● ● ● ● ●
I wish I spoke more English at home and with friends.
● ● ● ● ●
Speaking Spanish helps
● ● ● ● ●
346
me feel connected with my heritage. There are a lot of Spanish words that I don’t know.
● ● ● ● ●
There are a lot of English words that I don’t know.
● ● ● ● ●
I wish I understood more about Spanish grammar.
● ● ● ● ●
I wish I understood more about English grammar.
● ● ● ● ●
Speaking both English and Spanish is important to me.
● ● ● ● ●
Please indicate YES or NO for the following questions. If the answer is yes, please indicate the language spoken. If you do not wish to answer any of the following questions, you may circle NR for “No Response”.
I have family members who are non-native speakers of English. Yes No NR
I have classmates who are non-native speakers of English. Yes No NR
I have co-workers who are non-native speakers of English. Yes No NR
I have friends who are non-native speakers of English. Yes No NR
347
Appendix D: Language Proficiency Test (Spanish) From:
Geeslin, K. and Gudmestad, A. (forthcoming, 2010). An exploration of the range and frequency of occurrence of forms in potentially-variable structures in second language Spanish. Studies in Second Language Acquisition, 32, 3.
Read the story below about a Hispanic female college student and select the answer that best completes each sentence.
Creo que es muy interesante _____ de los hábitos alimenticios de la gente. Yo, por mi parte,
a. hablo b. hablar c. hablando
_____ vegetariana. Cuando voy a eventos sociales, como por ejemplo fiestas, bodas o bailes,
a. soy
b. estoy
c. tengo
espero que _____ comida vegetariana allí. Algunas personas dicen que _____ representa un
a. hay a. le
b. haya b. los
c. sea c. les
inconveniente proveer _____, pero yo creo que no _____ que ser así. De hecho, la comida
a. lo a. tiene b. la b. tenga
c. le c. tengo
vegetariana es muy fácil _____ preparar. Y cuando no _____ ofrece, puede ser _____ gran
a. en a. la a. un
348
b. a b. le b. una
c. de c. se c. el
problema. Yo recuerdo una vez que _____ a una fiesta de cumpleaños y _____ ser todo un
a. fui a. resultó
b. iba b. resultaba
c. voy c. resulté
desastre. La fiesta _____ en la casa de un amigo, y él había invitado a mucha gente. Me
a. estaba
b. era
c. fue
sorprendió porque _____ ser un estudiante de postgrado con poco dinero, _____ una gran
a. entre a. tuvo
b. por b. tenía
c. para c. tuviera
variedad de comida para los invitados. Yo creo que si me _____ tocado a mí dar la fiesta, no a. hubiera
b. habría c. había
_____ dado ni la mitad de lo que _____ allí. Pero pronto me _____ cuenta que él no había
a. hubiera a. era a. doy
b. habría b. había b. daba
c. había c. hubiera c. di
preparado nada vegetariano. Yo no pongo problemas por ese tipo de cosas, pero una amiga
349
_____ sí _____ hace. _____ a quejarse en frente de todo el mundo, mientras el anfitrión sólo
a. mía a. le a. Empezó
b. mi b. se b. Empezaba
c. de mí c. lo c. Empezado
sólo _____ la escena con _____ boca abierta. Yo le dije a mi amiga que _____ de causar tanto
a. miró a. su a. dejaba
b. miraba b. una b. deje
c. miraría c. la c. dejara
escándalo, pero no me puso atención. Por fin, el anfitrión dijo: “La próxima vez que tenga una
fiesta, _____ algo vegetariano.” Yo le dije después a mi amiga: “Mejor tarde que nunca, ¿no?”
a. prepararé
b. prepararía
c. preparara
350
Appendix E: Language attitude and cultural sensitivity questionnaire
From : Cushner, K. (1986). The Inventory of Cross-Cultural Sensitivity. Kent State University: School of Education.
-------------------
Circle the number that best corresponds to your level of agreement with each statement below.
1 = Strongly Disagree 7 = Strongly Agree
1. I speak only one language.
1 2 3 4 5 6 7
2. The way other people express themselves is very interesting to me.
1 2 3 4 5 6 7
3. I enjoy being with people from other cultures
1 2 3 4 5 6 7
4. Foreign influence in our country threatens our national identity.
1 2 3 4 5 6 7
5. Others’ feelings rarely influence decisions I make.
1 2 3 4 5 6 7
6. I cannot eat with chopsticks.
1 2 3 4 5 6 7
7. I avoid people who are different from me.
1 2 3 4 5 6 7
8. It is better that people from other cultures avoid one another.
1 2 3 4 5 6 7
9. Culturally mixed marriages are wrong.
1 2 3 4 5 6 7
351
10. I think people are basically alike.
1 2 3 4 5 6 7
11. I have never lived outside my own culture for any great length of time.
1 2 3 4 5 6 7
12. I have foreigners over to my home on a regular basis.
1 2 3 4 5 6 7
13. It makes me nervous to talk about people who are different than me.
1 2 3 4 5 6 7
14. I enjoy studying about people from other cultures.
1 2 3 4 5 6 7
15. People from other cultures do things differently because they do not know any other way.
1 2 3 4 5 6 7
16. There is usually more than one good way to get things done.
1 2 3 4 5 6 7
17. I listen to music from another culture on a regular basis.
1 2 3 4 5 6 7
18. I decorate my home or room with artifacts from other countries.
1 2 3 4 5 6 7
19. I feel uncomfortable when in a crowd of people.
1 2 3 4 5 6 7
20. The very existence of humanity depends upon our knowledge about other people.
1 2 3 4 5 6 7
21. Residential neighborhoods should be culturally separated.
352
1 2 3 4 5 6 7
22. I have many friends.
1 2 3 4 5 6 7
23. I dislike eating foods from other cultures.
1 2 3 4 5 6 7
24. I think about living within another culture in the future.
1 2 3 4 5 6 7
25. Moving into another culture would be easy.
1 2 3 4 5 6 7
26. I like to discuss issues with people from other cultures.
1 2 3 4 5 6 7
27. There should be tighter controls on the number of immigrants allowed into my country.
1 2 3 4 5 6 7
28. The more I know about people, the more I dislike them.
1 2 3 4 5 6 7
29. I read more national news than international news in the daily newspaper.
1 2 3 4 5 6 7
30. Crowds of foreigners frighten me.
1 2 3 4 5 6 7
31. When something newsworthy happens I seek out someone from that part of the world to discuss the issue with.
1 2 3 4 5 6 7
32. I eat ethnic foods at least twice a week.
1 2 3 4 5 6 7
353
Scoring the ICCS
The ICCS can be scored by subscales. Simply enter the number for each question you answered in the space provided under each subscale heading. Reverse the values for the items marked with an asterisk (*). For example, reverse scoring results in:
7=1, 6=2, 5=3, 4=4, 3=5, 2=6, 1=7
A total ICCS score is obtained by adding the various subscale scores together. Individuals can be ranked relative to others in a particular group. You can also identify relative strengths and weaknesses that may lead to more focused orientation and planning.
ICSS Scoring Guide
C Scale
Item Score
1*
6*
11*
12
17
18
23*
24
29*
32
TOTAL
B Scale
Item Score
2
7*
13*
19*
25*
30
TOTAL
I Scale
Item Score
3
8*
14
20
26
31
TOTAL
354
A Scale
Item Score
4*
9*
15*
21*
27*
TOTAL
E Scale
Item Score
5*
10
16
22
28*
TOTAL
TOTALS
C Scale
B Scale
I Scale
A Scale
E Scale
TOTAL ICCS SCORE
The five subscales and the range of scores include:
Subscale Range of Scores
Cultural Integration (C Scale) 10-70
Behavioral Scale (B Scale) 6-42
Intellectual Interaction (I Scale) 6-42
Attitude Toward Others (A Scale) 5-35
Empathy Scale (E Scale) 5-35
TOTAL SCORE RANGE 32-224
355
Appendix F: Participant demographic information
ID# Gen. Age Country born
Parents' country of
origin
Native language
Time spent studying Spanish
Age when started
studying Spanish
Current Spanish
class
Other languages
studied
Travel abroad Self ID terms
1F F 19 USA Mexico, D.F. Spanish 1 yr college 18 S114
(Biling Spanish II)
French
Every 3 years or so
visits Mexico
Latina, Hispanic, Mexicana,
Midwesterner, American
2F F NR USA Mexico English 1 yr college 20 S114
(Biling Spanish II)
French (fair), Mandarin (fair, poor,
poor), Japanese
(poor)
Mexico every
summer No response
3F F 19 USA Mexico English 1 yr
elementary, 1 yr college
8 S114
(Biling Spanish II)
French (poor, good,
fair)
Mexico, every
summer
Hispanic, Mexicana
4F F 18 USA Puerto Rico English and Spanish
2 yrs HS, 2 sem college 16
S114 (Biling
Spanish II) No
Puerto Rico,
every 3-4 years
Puertorriqueña
1M M 24 Mexico: moved to
US at 8 yrs Mexico Spanish 1 sem HS, 1
sem college 18 S114
(Biling Spanish II)
No No
Latino, Hispanic, Mexicano, American
2M M 19 USA
Mother - Valparaiso
Father -Zacatecas (Mexico)
Spanish 1 sem college 19 S114
(Biling Spanish II)
No Once a year to Mexico
Latino, Hispanic, Mexicano, American
356
ID# Gen. Age Current city
Country born
Parents' country of
origin
Native language
Time spent
studying Spanish
Age when started
studying Spanish
Current Spanish
class
Other languages
studied
Travel abroad
Self ID terms
5F F 20 Chicago, Il USA Mexico Spanish
4 yrs HS, 1 yr
college 14 S114 (Biling
Spanish II) French (poor)
Infrequent. Mexico
last year, first time in 10 yrs
Latina, Hispanic, Mexicana
6F F 22 Chicago, Il USA
Mother - DF
Father - Jalisco
(Meixco)
Spanish
preschool up
through 3rd grade; then high
school and college
5 (preschool aged)
S206 and S210,
finished 114
Italian (good)
Every few years
Latina, Hispanic, Chicana,
Mexicana, American
7F F 21 Chicago, Il USA
Mother - DF
Father - Michoacan
Spanish No response No response 212 and 303;
finished 114 No No
Latina, Hispanic, Chicana, Mexicana
3M M 19 Chicago, Il USA
Mother-Mexico Father-Spain
Spanish
5 yrs in high
school and college
14
202-grammar,
210 literature,
204-writing
French (good, fair,
good), English (good)
Mexico twice a year, Spain every
summer
Latino, Mexicano, American,
other: Spanish
8F F 21 Chicago, Il
Mexico: moved
to US at 2 yrs
Mexico, D.F. English
1 yr HS, 3 Sem
college 17
202--Grammar,
already took 113-114
Italian (good,
fair, fair)
Mexico, every two
years Latina
357
ID# Gen. Age Current city
Country born
Parents' country of origin
Native language
Time spent
studying Spanish
Age when started
studying Spanish
Current Spanish class
Other languag
es studied
Travel abroad
Self ID terms
9F F 22 Chicago, Il USA Mexico Spanish
4-8 yrs preschool; 3rd grade--bilingual education
4
380--Professional,
Latinos in Chicago, Ind
study
No Every year Mexico Mexicana
10F F 21 Chicago, Il
Mexico, DF.
Moved to US at 6
yrs
Mexico Spanish
bilingual preschool; then high
school and college
overhearing at birth; study at 4 yrs and 17
yrs
202-grammar, 210
literature, 204-writing,
206-linguistics
English (good)
Spain once, visiting
friends and family in
Mexico and Venezuela
soon
Mexicana
11F F 19 Chicago, Il
USA--Chicago
Mexico, D.F. Spanish
overheard Spanish
from birth;
English in school;
Spanish in college
overhearing at birth; study 18
yrs
204 English, Spanish
(fair)
every few years
No response
12F F 19 Chicago, Il USA
Mother-Chicago Father-
Guanajuato
English
17-19 yrs of age in
high school and
college
birth-grew up
overhearing, study at
17
204--writing, 210 text analysis
NO
Guanajuato, about every 3 years
Latina, Mexicana Hispanic
F13 F 19 Chicago, Il USA Jalisco,
Mexico Spanish High
school and college
15
202--Grammar,
already took 113-114
NO every few years to Jalisco,
Latina, Hispanic, Chicana,
Mexicana, American
358
Appendix G: Total vowels analyzed in the analyses (N)
1) Total number of vowel tokens collapsed across all speakers, stress types, syllable types, and tasks.
vowel N
a 937 e 796 i 604 o 555 u 450 Total 3342
2) Total number of tonic and atonic vowels, organized by stress.
stress vowel N
A a 304
e 370
i 176
o 231
u 168
Total 1249
T a 633
e 426
i 428
o 324
u 282
Total 2093
Total a 937
e 796
i 604
o 555
u 450
Total 3342
359
3) Total number of vowels produced in closed and open syllables, organized by syllable type.
syll vowel N
C a 295
e 243
i 149
o 201
u 121
Total 1009
O a 642
e 553
i 455
o 354
u 329
Total 2333
Total a 937
e 796
i 604
o 555
u 450
Total 3342
4) Total number of vowels produced in the three speech tasks, organized by vowel.
vowel task N
a 1 378
2 332
3 227
Total 937
e 1 294
2 324
3 178
Total 796
i 1 171
2 214
360
3 219
Total 604
o 1 180
2 174
3 201
Total 555
u 1 88
2 203
3 159
Total 450
Total 1 1111
2 1247
3 984
Total 3342
5) Total number of atonic and tonic vowels in each of the three speech tasks.
task stress vowel N
1 A a 120
e 188
i 63
o 90
u 35
Total 496
T a 258
e 106
i 108
o 90
u 53
Total 615
Total a 378
e 294
i 171
o 180
u 88
361
Total 1111
2 A a 147
e 156
i 83
o 84
u 86
Total 556
T a 185
e 168
i 131
o 90
u 117
Total 691
Total a 332
e 324
i 214
o 174
u 203
Total 1247
3 A a 37
e 26
i 30
o 57
u 47
Total 197
T a 190
e 152
i 189
o 144
u 112
Total 787
Total a 227
e 178
i 219
o 201
u 159
Total 984
362
Total A a 304
e 370
i 176
o 231
u 168
Total 1249
T a 633
e 426
i 428
o 324
u 282
Total 2093
Total a 937
e 796
i 604
o 555
u 450
Total 3342
6) Total number of vowels produced in open and closed syllables in each of the three speech tasks.
task syll vowel N
1 C a 108
e 82
i 36
o 83
u 11
Total 320
O a 270
e 212
i 135
o 97
u 77
Total 791
363
Total a 378
e 294
i 171
o 180
u 88
Total 1111
2 C a 142
e 133
i 74
o 58
u 61
Total 468
O a 190
e 191
i 140
o 116
u 142
Total 779
Total a 332
e 324
i 214
o 174
u 203
Total 1247
3 C a 45
e 28
i 39
o 60
u 49
Total 221
O a 182
e 150
i 180
o 141
u 110
Total 763
Total a 227
364
e 178
i 219
o 201
u 159
Total 984
Total C a 295
e 243
i 149
o 201
u 121
Total 1009
O a 642
e 553
i 455
o 354
u 329
Total 2333
Total a 937
e 796
i 604
o 555
u 450
Total 3342
7) Total number of vowels organized by course level.
CLevel vowel N
1 a 379
e 316
i 236
o 224
u 181
Total 1336
2 a 558
e 480
i 368
365
o 331
u 269
Total 2006
Total a 937
e 796
i 604
o 555
u 450
Total 3342
8) Total number of vowels organized by travel group.
Travel vowel N
0 a 274
e 229
i 166
o 164
u 121
Total 954
1 a 325
e 283
i 207
o 184
u 159
Total 1158
2 a 338
e 284
i 231
o 207
u 170
Total 1230
Total a 937
e 796
i 604
o 555
u 450
366
Travel vowel N
0 a 274
e 229
i 166
o 164
u 121
Total 954
1 a 325
e 283
i 207
o 184
u 159
Total 1158
2 a 338
e 284
i 231
o 207
u 170
Total 1230
Total a 937
e 796
i 604
o 555
u 450
Total 3342
367
Appendix H: Results of statistical analyses conducted with F1
1) Table of Type II Tests of Fixed Effects indicates which main effects and interactions were significant.
Type III Tests of Fixed Effectsa
Source Numerator df Denominator df F Sig.
Intercept 1 7.989 19.436 .002
vowel 4 3254.080 16.560 .000
task 2 3254.389 25.244 .000
stress 1 3254.209 204.223 .000
syll 1 3254.123 1.986 .159
Gender 1 8.004 7.580 .025
Group 1 8.010 .829 .389
Travel 2 7.998 2.682 .128
Grammar 1 8.010 .007 .934
ICCSTotal 1 7.991 1.502 .255
Spanuse 1 8.002 .451 .521
vowel * task 8 3254.141 25.853 .000
vowel * stress 4 3254.160 62.184 .000
vowel * syll 4 3254.093 .853 .491
vowel * task * stress 10 3254.174 2.600 .004
vowel * task * syll 10 3254.103 6.704 .000
vowel * Gender 4 3254.100 68.444 .000
vowel * Group 4 3254.072 2.423 .046
vowel * Travel 8 3254.078 19.723 .000
vowel * Grammar 4 3254.031 10.281 .000
vowel * ICCSTotal 4 3254.079 2.865 .022
vowel * Spanuse 4 3254.081 5.704 .000
a. Dependent Variable: F1.
368
2) Pairwise comparisons of the main effect of vowel, which indicates which vowels differ statistically from each other.
Pairwise Comparisonsb
(I) vowel (J) vowel
Mean
Difference (I-
J) Std. Error df Sig.a
95% Confidence Interval for
Differencea
Lower Bound
Upper
Bound
a e 188.671* 4.697 3254.027 .000 175.477 201.865
i 319.458* 5.014 3254.126 .000 305.373 333.543
o 150.365* 4.831 3254.229 .000 136.795 163.936
u 267.164* 5.747 3254.121 .000 251.020 283.308
e a -188.671* 4.697 3254.027 .000 -201.865 -175.477
i 130.787* 5.228 3254.066 .000 116.102 145.472
o -38.305* 5.054 3254.217 .000 -52.502 -24.109
u 78.493* 5.936 3254.111 .000 61.820 95.167
i a -319.458* 5.014 3254.126 .000 -333.543 -305.373
e -130.787* 5.228 3254.066 .000 -145.472 -116.102
o -169.093* 5.351 3254.314 .000 -184.123 -154.063
u -52.294* 6.186 3254.063 .000 -69.671 -34.917
o a -150.365* 4.831 3254.229 .000 -163.936 -136.795
e 38.305* 5.054 3254.217 .000 24.109 52.502
i 169.093* 5.351 3254.314 .000 154.063 184.123
u 116.799* 6.043 3254.255 .000 99.824 133.774
u a -267.164* 5.747 3254.121 .000 -283.308 -251.020
e -78.493* 5.936 3254.111 .000 -95.167 -61.820
i 52.294* 6.186 3254.063 .000 34.917 69.671
o -116.799* 6.043 3254.255 .000 -133.774 -99.824
Based on estimated marginal means
*. The mean difference is significant at the .05 level.
a. Adjustment for multiple comparisons: Bonferroni.
b. Dependent Variable: F1.
369
3) Pairwise comparisons of the main effect of task (speech style). “1” represents the
NRT, “2” the PIT, and “3” the CPT.
Pairwise Comparisonsb
(I) task (J) task
Mean
Difference (I-J) Std. Error df Sig.a
95% Confidence Interval for
Differencea
Lower Bound Upper Bound
1 2 20.189* 3.078 3254.616 .000 12.818 27.561
3 21.605* 3.557 3254.445 .000 13.086 30.123
2 1 -20.189* 3.078 3254.616 .000 -27.561 -12.818
3 1.416 3.034 3254.126 1.000 -5.852 8.683
3 1 -21.605* 3.557 3254.445 .000 -30.123 -13.086
2 -1.416 3.034 3254.126 1.000 -8.683 5.852
Based on estimated marginal means
*. The mean difference is significant at the .05 level.
a. Adjustment for multiple comparisons: Bonferroni.
b. Dependent Variable: F1.
4) Pairwise comparisons of the main effect of stress. “T” indicates tonic, and “A” indicates atonic.
Pairwise Comparisonsb
(I)
stress
(J)
stress
Mean Difference
(I-J)
Std.
Error df Sig.a
95% Confidence Interval for
Differencea
Lower Bound Upper Bound
A T -34.322* 2.402 3254.209 .000 -39.031 -29.613
T A 34.322* 2.402 3254.209 .000 29.613 39.031
Based on estimated marginal means
*. The mean difference is significant at the .05 level.
a. Adjustment for multiple comparisons: Bonferroni.
b. Dependent Variable: F1.
370
5) Pairwise comparisons of the significant vowel by task interaction.
Pairwise Comparisonsb
vowel (I) task (J) task
Mean
Difference (I-
J) Std. Error df Sig.a
95% Confidence Interval for
Differencea
Lower Bound Upper Bound
a 1 2 -15.891* 4.582 3254.095 .002 -26.867 -4.916
3 -58.223* 6.287 3254.036 .000 -73.282 -43.163
2 1 15.891* 4.582 3254.095 .002 4.916 26.867
3 -42.331* 6.175 3254.040 .000 -57.123 -27.540
3 1 58.223* 6.287 3254.036 .000 43.163 73.282
2 42.331* 6.175 3254.040 .000 27.540 57.123
e 1 2 37.513* 4.953 3254.414 .000 25.648 49.377
3 46.078* 7.534 3254.212 .000 28.032 64.124
2 1 -37.513* 4.953 3254.414 .000 -49.377 -25.648
3 8.565 7.243 3254.046 .711 -8.783 25.914
3 1 -46.078* 7.534 3254.212 .000 -64.124 -28.032
2 -8.565 7.243 3254.046 .711 -25.914 8.783
i 1 2 28.944* 6.829 3254.216 .000 12.587 45.301
3 54.020* 8.076 3254.186 .000 34.675 73.364
2 1 -28.944* 6.829 3254.216 .000 -45.301 -12.587
3 25.075* 7.221 3254.053 .002 7.780 42.370
3 1 -54.020* 8.076 3254.186 .000 -73.364 -34.675
2 -25.075* 7.221 3254.053 .002 -42.370 -7.780
o 1 2 21.442* 6.221 3254.378 .002 6.541 36.343
3 16.782* 6.203 3254.380 .021 1.923 31.640
2 1 -21.442* 6.221 3254.378 .002 -36.343 -6.541
3 -4.660 6.336 3254.062 1.000 -19.836 10.516
3 1 -16.782* 6.203 3254.380 .021 -31.640 -1.923
2 4.660 6.336 3254.062 1.000 -10.516 19.836
u 1 2 28.938* 10.260 3254.406 .014 4.364 53.513
3 49.368* 10.752 3254.358 .000 23.615 75.121
2 1 -28.938* 10.260 3254.406 .014 -53.513 -4.364
3 20.429* 6.860 3254.038 .009 3.998 36.861
3 1 -49.368* 10.752 3254.358 .000 -75.121 -23.615
2 -20.429* 6.860 3254.038 .009 -36.861 -3.998 Dependent variable: F1. Based on estimated marginal means *. The mean difference is significant at the.05 level. a. Adjustment for multiple comparisons: Bonferroni.
371
6) Pairwise comparisons of the vowel by stress interaction.
Pairwise Comparisonsb
vowel (I) stress (J) stress
Mean
Difference (I-
J)
Std.
Error df Sig.a
95% Confidence
Interval for Differencea
Lower
Bound
Upper
Bound
a A T -79.971* 4.627 3254.093 .000 -89.042 -70.899
T A 79.971* 4.627 3254.093 .000 70.899 89.042
e A T -67.921* 5.294 3254.187 .000 -78.300 -57.542
T A 67.921* 5.294 3254.187 .000 57.542 78.300
i A T 15.929* 5.524 3254.153 .004 5.098 26.760
T A -15.929* 5.524 3254.153 .004 -26.760 -5.098
o A T -39.189* 5.341 3254.263 .000 -49.660 -28.717
T A 39.189* 5.341 3254.263 .000 28.717 49.660
u A T -.459 5.973 3254.161 .939 -12.170 11.252
T A .459 5.973 3254.161 .939 -11.252 12.170 Based on estimated marginal means
*. The mean difference is significant at the .05 level.
a. Adjustment for multiple comparisons: Bonferroni.
b. Dependent Variable: F1.
7) Pairwise comparisons of the significant interaction between vowel, task, and stress. The 1,2,3 stand for the NRT, PIT, and CPT respectively. “T” denotes tonic, and “A” denotes atonic.
Pairwise Comparisonsb
vowel task
(I)
stress
(J)
stress
Mean
Difference (I-
J)
Std.
Error df Sig.a
95% Confidence
Interval for Differencea
Lower
Bound
Upper
Bound
a 1 A T -70.477* 6.246 3254.232 .000 -82.723 -58.232
T A 70.477* 6.246 3254.232 .000 58.232 82.723
2 A T -72.141* 6.203 3254.061 .000 -84.304 -59.978
T A 72.141* 6.203 3254.061 .000 59.978 84.304
372
3 A T -97.295* 10.743 3254.107 .000 -118.359 -76.230
T A 97.295* 10.743 3254.107 .000 76.230 118.359
e 1 A T -57.375* 6.828 3254.171 .000 -70.764 -43.986
T A 57.375* 6.828 3254.171 .000 43.986 70.764
2 A T -60.316* 6.694 3254.066 .000 -73.441 -47.190
T A 60.316* 6.694 3254.066 .000 47.190 73.441
3 A T -86.073* 12.670 3254.087 .000 -110.916 -61.231
T A 86.073* 12.670 3254.087 .000 61.231 110.916
i 1 A T 36.962* 9.051 3254.612 .000 19.217 54.708
T A -36.962* 9.051 3254.612 .000 -54.708 -19.217
2 A T -8.259 7.922 3254.066 .297 -23.791 7.274
T A 8.259 7.922 3254.066 .297 -7.274 23.791
3 A T 19.082 11.412 3254.006 .095 -3.294 41.459
T A -19.082 11.412 3254.006 .095 -41.459 3.294
o 1 A T -42.699* 8.493 3254.747 .000 -59.351 -26.048
T A 42.699* 8.493 3254.747 .000 26.048 59.351
2 A T -41.737* 8.581 3254.098 .000 -58.563 -24.912
T A 41.737* 8.581 3254.098 .000 24.912 58.563
3 A T -33.130* 10.537 3254.013 .002 -53.789 -12.471
T A 33.130* 10.537 3254.013 .002 12.471 53.789
u 1 A T 7.773 12.625 3254.294 .538 -16.982 32.527
T A -7.773 12.625 3254.294 .538 -32.527 16.982
2 A T 2.297 8.027 3254.024 .775 -13.440 18.035
T A -2.297 8.027 3254.024 .775 -18.035 13.440
3 A T -11.448 9.875 3254.039 .246 -30.811 7.915
T A 11.448 9.875 3254.039 .246 -7.915 30.811 Based on estimated marginal means. *. The mean difference is significant at the .05 level. a. Adjustment for multiple comparisons: Bonferroni. b. Dependent Variable: F1
373
8) Interaction between vowel, task, and syllable type. The “C” stands for closed (syllable) and the “O” for open (syllable). The numbers 1, 2, 3 stand for the NRT, PIT, and CPT respectively.
Pairwise Comparisonsb
vowel task
(I)
syll
(J)
syll
Mean Difference
(I-J)
Std.
Error df Sig.a
95% Confidence Interval for
Differencea
Lower Bound
Upper
Bound
a 1 C O -25.083* 6.436 3254.215 .000 -37.703 -12.463
O C 25.083* 6.436 3254.215 .000 12.463 37.703
2 C O 15.028* 6.221 3254.084 .016 2.830 27.225
O C -15.028* 6.221 3254.084 .016 -27.225 -2.830
3 C O 27.709* 9.943 3254.011 .005 8.214 47.204
O C -27.709* 9.943 3254.011 .005 -47.204 -8.214
e 1 C O 10.972 7.308 3254.242 .133 -3.357 25.301
O C -10.972 7.308 3254.242 .133 -25.301 3.357
2 C O -11.928 6.798 3254.040 .079 -25.256 1.400
O C 11.928 6.798 3254.040 .079 -1.400 25.256
3 C O -9.693 12.286 3254.046 .430 -33.782 14.396
O C 9.693 12.286 3254.046 .430 -14.396 33.782
i 1 C O 9.069 10.636 3254.103 .394 -11.785 29.923
O C -9.069 10.636 3254.103 .394 -29.923 11.785
2 C O 2.229 8.133 3254.080 .784 -13.716 18.175
O C -2.229 8.133 3254.080 .784 -18.175 13.716
3 C O -2.056 10.270 3254.029 .841 -22.192 18.079
O C 2.056 10.270 3254.029 .841 -18.079 22.192
o 1 C O 37.923* 8.490 3254.179 .000 21.276 54.571
O C -37.923* 8.490 3254.179 .000 -54.571 -21.276
2 C O -5.723 9.030 3254.021 .526 -23.429 11.982
O C 5.723 9.030 3254.021 .526 -11.982 23.429
3 C O -29.074* 10.376 3254.029 .005 -49.419 -8.729
O C 29.074* 10.376 3254.029 .005 8.729 49.419
u 1 C O 19.815 18.287 3254.362 .279 -16.040 55.670
O C -19.815 18.287 3254.362 .279 -55.670 16.040
2 C O 21.376* 8.660 3254.014 .014 4.396 38.355
O C -21.376* 8.660 3254.014 .014 -38.355 -4.396
3 C O -6.400 9.758 3254.064 .512 -25.532 12.732
374
O C 6.400 9.758 3254.064 .512 -12.732 25.532 Based on estimated marginal means. *. The mean difference is significant at the .05 level. a. Adjustment for multiple comparisons: Bonferroni. b. Dependent variable: F1 9) Pairwise comparisons of the significant interaction between vowel and course level. In the table, the variable is labeled as “group.” The “1” represents the intermediate-level HS, and “2” denotes the advanced-level group.
Pairwise Comparisonsb
vowel (I) Group
(J)
Group
Mean
Difference (I-
J)
Std.
Error df Sig.a
95% Confidence Interval
for Differencea
Lower Bound
Upper
Bound
a 1 2 -30.800 22.987 8.557 .215 -83.214 21.614
2 1 30.800 22.987 8.557 .215 -21.614 83.214
e 1 2 -23.556 23.103 8.731 .335 -76.066 28.954
2 1 23.556 23.103 8.731 .335 -28.954 76.066
i 1 2 -21.261 23.325 9.071 .386 -73.963 31.441
2 1 21.261 23.325 9.071 .386 -31.441 73.963
o 1 2 -5.012 23.414 9.210 .835 -57.794 47.770
2 1 5.012 23.414 9.210 .835 -47.770 57.794
u 1 2 -22.283 23.536 9.404 .367 -75.179 30.613
2 1 22.283 23.536 9.404 .367 -30.613 75.179
Based on estimated marginal means
*. The mean difference is significant at the .05 level.
a. Adjustment for multiple comparisons: Bonferroni.
b. Dependent Variable: F1.
375
10) Parameter estimates for the significant vowel by grammar score interaction. The [vowel=u]*grammar category was set to zero. The significance values indicate which vowels had slopes that differed significantly from zero.
95% Confidence
Interval
Parameter Estimate Std.
Error df t Sig. Lower Bound
Upper Bound
Grammar -1.232 4.040 9.429 -0.280 0.785 -11.121 8.656
[vowel=a]*grammar -3.203 1.632 3254.033 -1.963 0.050 -6.402 -0.004
[vowel=e]*grammar 2.018 1.676 3254.036 1.204 0.229 -1.267 5.304
[vowel=i]*grammar -0.826 1.779 3254.032 -0.464 0.643 -4.315 2.664
[vowel=o]*grammar 6.380 1.834 3254.004 3.478 0.001 2.782 9.976
[vowel=u]*grammar 0 0 . . . . . 11) Parameter estimates for the significant vowel by cultural sensitivity interaction (ICCS total). The [vowel=u]*ICCS total category was set to zero. The significance values indicate which vowels had slopes that differed significantly from zero.
95% Confidence
Interval
Parameter Estimate Std.
Error df t Sig. Lower Bound
Upper Bound
ICCS total -0.761 0.765 9.331 -0.995 0.345 -2.482 0.960
[vowel=a]*ICCS total -0.101 0.275 3254.031 -0.367 0.714 -0.641 0.439
[vowel=e]*ICCS total -0.556 0.285 3254.063 -1.953 0.051 -1.115 0.002
[vowel=i]*ICCS total 0.275 0.298 3254.020 0.921 0.357 -0.310 0.861
[vowel=o]*ICCS total -0.322 0.303 3254.152 -1.062 0.288 -0.918 0.272
[vowel=u]*ICCS total 0 0 . . . . . 12) Parameter estimates for the significant vowel by Spanish use interaction. The [vowel=u]*Spanish use category was set to zero. The significance values indicate which vowels had slopes that differed significantly from zero.
95% Confidence
Interval
Parameter Estimate Std.
Error df t Sig. Lower Bound
Upper Bound
Spanish use 1.980 3.118 9.443 0.635 0.540 -5.023 8.982
[vowel=a]*Spanish use 2.395 1.142 3254.090 2.098 0.036 0.156 4.635
[vowel=e]*Spanish use 0.521 1.178 3254.201 0.442 0.658 -1.789 2.832
[vowel=i]*Spanish use -0.050 1.245 3254.117 -0.041 0.968 -2.492 2.391
[vowel=o]*Spanish use -2.722 1.298 3254.090 -2.096 0.036 -5.269 -0.175
[vowel=u]*Spanish use 0 0 . . . . .
376
Appendix I: Results of statistical analyses conducted with F2
1) Table of Type II Tests of Fixed Effects indicates which main effects and interactions were significant.
Type III Tests of Fixed Effectsa
Source Numerator df Denominator df F Sig.
Intercept 1 8.013 34.084 .000
vowel 4 3254.136 19.229 .000
task 2 3254.550 6.374 .002
stress 1 3254.309 2.416 .120
syll 1 3254.193 2.323 .128
Gender 1 8.033 3.921 .083
Group 1 8.041 .463 .515
Travel 2 8.025 .162 .853
Grammar 1 8.042 .151 .708
ICCSTotal 1 8.016 1.697 .229
Spanuse 1 8.030 .348 .571
vowel * task 8 3254.218 23.711 .000
vowel * stress 4 3254.244 46.598 .000
vowel * syll 4 3254.153 5.837 .000
vowel * task * stress 10 3254.263 13.866 .000
vowel * task * syll 10 3254.167 4.444 .000
vowel * Gender 4 3254.162 75.974 .000
vowel * Group 4 3254.125 18.114 .000
vowel * Travel 8 3254.133 23.615 .000
vowel * Grammar 4 3254.070 23.228 .000
vowel * ICCSTotal 4 3254.134 .850 .493
vowel * Spanuse 4 3254.137 30.542 .000
a. Dependent Variable: F2.
377
2) Pairwise comparisons of the main effect of vowel, which indicates which vowels differ statistically from each other.
Pairwise Comparisonsb
(I) vowel (J) vowel
Mean
Difference (I-
J) Std. Error df Sig.a
95% Confidence Interval for
Differencea
Lower Bound
Upper
Bound
a e -363.502* 14.347 3254.064 .000 -403.801 -323.202
i -677.573* 15.315 3254.197 .000 -720.592 -634.555
o 363.528* 14.756 3254.336 .000 322.080 404.976
u 320.720* 17.554 3254.191 .000 271.412 370.029
e a 363.502* 14.347 3254.064 .000 323.202 403.801
i -314.071* 15.967 3254.117 .000 -358.923 -269.220
o 727.030* 15.437 3254.321 .000 683.669 770.391
u 684.222* 18.130 3254.177 .000 633.295 735.149
i a 677.573* 15.315 3254.197 .000 634.555 720.592
e 314.071* 15.967 3254.117 .000 269.220 358.923
o 1041.101* 16.343 3254.450 .000 995.195 1087.008
u 998.294* 18.895 3254.113 .000 945.219 1051.369
o a -363.528* 14.756 3254.336 .000 -404.976 -322.080
e -727.030* 15.437 3254.321 .000 -770.391 -683.669
i -1041.101* 16.343 3254.450 .000 -1087.008 -995.195
u -42.808 18.458 3254.371 .204 -94.655 9.039
u a -320.720* 17.554 3254.191 .000 -370.029 -271.412
e -684.222* 18.130 3254.177 .000 -735.149 -633.295
i -998.294* 18.895 3254.113 .000 -1051.369 -945.219
o 42.808 18.458 3254.371 .204 -9.039 94.655 Based on estimated marginal means. *. The mean difference is significant at the .05 level. a. Adjustment for multiple comparisons: Bonferroni. b. Dependent Variable: F2.
378
3) Pairwise comparisons of the main effect of task (speech style). “1” represents the
NRT, “2” the PIT, and “3” the CPT.
Pairwise Comparisonsb
(I) task (J) task
Mean
Difference (I-J) Std. Error df Sig.a
95% Confidence Interval for
Differencea
Lower Bound
Upper
Bound
1 2 -15.725 9.400 3254.854 .283 -38.239 6.790
3 -38.385* 10.863 3254.626 .001 -64.403 -12.367
2 1 15.725 9.400 3254.854 .283 -6.790 38.239
3 -22.661* 9.267 3254.198 .044 -44.857 -.464
3 1 38.385* 10.863 3254.626 .001 12.367 64.403
2 22.661* 9.267 3254.198 .044 .464 44.857
Based on estimated marginal means
a. Adjustment for multiple comparisons: Bonferroni.
*. The mean difference is significant at the .05 level.
b. Dependent Variable: F2.
4) Pairwise comparisons of the vowel by task interaction. The numbers 1, 2, and 3 represent the NRT, PIT, and CPT respectively.
Pairwise Comparisonsb
vowel
(I)
task
(J)
task
Mean Difference
(I-J)
Std.
Error df Sig.a
95% Confidence Interval for
Differencea
Lower Bound
Upper
Bound
a 1 2 23.222 13.996 3254.155 .291 -10.300 56.745
3 57.040* 19.203 3254.077 .009 11.044 103.035
2 1 -23.222 13.996 3254.155 .291 -56.745 10.300
3 33.817 18.861 3254.081 .219 -11.360 78.995
3 1 -57.040* 19.203 3254.077 .009 -103.035 -11.044
2 -33.817 18.861 3254.081 .219 -78.995 11.360
e 1 2 -27.066 15.129 3254.585 .221 -63.303 9.172
3 -242.642* 23.012 3254.314 .000 -297.760 -187.523
2 1 27.066 15.129 3254.585 .221 -9.172 63.303
3 -215.576* 22.122 3254.090 .000 -268.564 -162.588
3 1 242.642* 23.012 3254.314 .000 187.523 297.760
379
2 215.576* 22.122 3254.090 .000 162.588 268.564
i 1 2 -64.229* 20.858 3254.318 .006 -114.189 -14.270
3 -131.978* 24.667 3254.278 .000 -191.061 -72.895
2 1 64.229* 20.858 3254.318 .006 14.270 114.189
3 -67.749* 22.054 3254.099 .006 -120.573 -14.924
3 1 131.978* 24.667 3254.278 .000 72.895 191.061
2 67.749* 22.054 3254.099 .006 14.924 120.573
o 1 2 31.972 19.001 3254.536 .278 -13.539 77.484
3 84.847* 18.947 3254.538 .000 39.464 130.229
2 1 -31.972 19.001 3254.536 .278 -77.484 13.539
3 52.874* 19.352 3254.111 .019 6.522 99.227
3 1 -84.847* 18.947 3254.538 .000 -130.229 -39.464
2 -52.874* 19.352 3254.111 .019 -99.227 -6.522
u 1 2 -42.522 31.336 3254.574 .525 -117.580 32.535
3 40.807 32.839 3254.509 .642 -37.850 119.465
2 1 42.522 31.336 3254.574 .525 -32.535 117.580
3 83.330* 20.953 3254.079 .000 33.144 133.516
3 1 -40.807 32.839 3254.509 .642 -119.465 37.850
2 -83.330* 20.953 3254.079 .000 -133.516 -33.144 Based on estimated marginal means. *. The mean difference is significant at the .05 level. a. Adjustment for multiple comparisons: Bonferroni. b. Dependent Variable: F2.
5) Pairwise comparisons of the vowel by stress interaction. “T” indicates tonic, and “A” indicates atonic.
Pairwise Comparisonsb
vowel
(I)
stress
(J)
stress
Mean Difference
(I-J)
Std.
Error df Sig.a
95% Confidence Interval for
Differencea
Lower Bound
Upper
Bound
a A T -9.928 14.131 3254.153 .482 -37.635 17.779
T A 9.928 14.131 3254.153 .482 -17.779 37.635
e A T -41.008* 16.168 3254.279 .011 -72.709 -9.307
T A 41.008* 16.168 3254.279 .011 9.307 72.709
i A T -189.418* 16.872 3254.233 .000 -222.499 -156.337
T A 189.418* 16.872 3254.233 .000 156.337 222.499
380
o A T 89.938* 16.312 3254.382 .000 57.955 121.922
T A -89.938* 16.312 3254.382 .000 -121.922 -57.955
u A T 93.409* 18.243 3254.245 .000 57.640 129.179
T A -93.409* 18.243 3254.245 .000 -129.179 -57.640
Based on estimated marginal means
a. Adjustment for multiple comparisons: Bonferroni.
*. The mean difference is significant at the .05 level.
b. Dependent Variable: F2. 6) Pairwise comparisons of the vowel by syllable type interaction. “C” indicates a closed syllable and “O” an open syllable.
Pairwise Comparisonsb
vowel
(I)
syll
(J)
syll
Mean Difference
(I-J)
Std.
Error df Sig.a
95% Confidence Interval for
Differencea
Lower Bound
Upper
Bound
a C O 40.635* 13.624 3254.150 .003 13.923 67.346
O C -40.635* 13.624 3254.150 .003 -67.346 -13.923
e C O -29.176 16.115 3254.172 .070 -60.773 2.421
O C 29.176 16.115 3254.172 .070 -2.421 60.773
i C O -35.963* 17.131 3254.082 .036 -69.551 -2.374
O C 35.963* 17.131 3254.082 .036 2.374 69.551
o C O 30.413 16.471 3254.175 .065 -1.881 62.707
O C -30.413 16.471 3254.175 .065 -62.707 1.881
u C O 53.726* 22.820 3254.250 .019 8.984 98.469
O C -53.726* 22.820 3254.250 .019 -98.469 -8.984
Based on estimated marginal means
a. Adjustment for multiple comparisons: Bonferroni.
*. The mean difference is significant at the .05 level.
b. Dependent Variable: F2.
381
7) Pairwise comparisons of the significant interaction between vowel, task, and stress. The 1,2,3 stand for the NRT, PIT, and CPT respectively. “T” denotes tonic, and “A” denotes atonic.
Pairwise Comparisonsb
vowel task
(I)
stress
(J)
stress
Mean
Difference (I-J)
Std.
Error df
Sig.a
95% Confidence Interval
for Differencea
Lower Bound
Upper
Bound
a 1 A T 62.358* 19.076 3254.341 .001 24.956 99.759
T A -62.358* 19.076 3254.341 .001 -99.759 -24.956
2 A T -16.729 18.947 3254.110 .377 -53.879 20.421
T A 16.729 18.947 3254.110 .377 -20.421 53.879
3 A T -75.413* 32.814 3254.173 .022 -139.751 -11.075
T A 75.413* 32.814 3254.173 .022 11.075 139.751
e 1 A T -192.323* 20.856 3254.258 .000 -233.215 -151.430
T A 192.323* 20.856 3254.258 .000 151.430 233.215
2 A T -128.771* 20.446 3254.116 .000 -168.860 -88.683
T A 128.771* 20.446 3254.116 .000 88.683 168.860
3 A T 198.070* 38.699 3254.145 .000 122.193 273.947
T A -198.070* 38.699 3254.145 .000 -273.947 -122.193
i 1 A T -241.357* 27.643 3254.849 .000 -295.557 -187.158
T A 241.357* 27.643 3254.849 .000 187.158 295.557
2 A T -76.574* 24.196 3254.117 .002 -124.014 -29.134
T A 76.574* 24.196 3254.117 .002 29.134 124.014
3 A T -250.323* 34.857 3254.036 .000 -318.667 -181.978
T A 250.323* 34.857 3254.036 .000 181.978 318.667
o 1 A T 53.990* 25.939 3255.029 .037 3.132 104.848
T A -53.990* 25.939 3255.029 .037 -104.848 -3.132
2 A T 97.882* 26.210 3254.160 .000 46.491 149.272
T A -97.882* 26.210 3254.160 .000 -149.272 -46.491
3 A T 117.943* 32.182 3254.046 .000 54.845 181.042
T A -117.943* 32.182 3254.046 .000 -181.042 -54.845
u 1 A T 14.213 38.562 3254.424 .712 -61.395 89.821
T A -14.213 38.562 3254.424 .712 -89.821 61.395
2 A T 172.963* 24.516 3254.060 .000 124.895 221.031
T A -172.963* 24.516 3254.060 .000 -221.031 -124.895
3 A T 93.052* 30.163 3254.080 .002 33.913 152.192
382
T A -93.052* 30.163 3254.080 .002 -152.192 -33.913 Based on estimated marginal means. *. The mean difference is significant at the .05 level. a. Adjustment for multiple comparisons: Bonferroni. b. Dependent Variable: F2.
8) Interaction between vowel, task, and syllable type. The “C” stands for closed (syllable) and the “O” for open (syllable). The numbers 1, 2, 3 stand for the NRT, PIT, and CPT respectively.
Pairwise Comparisonsb
vowel task
(I)
syll
(J)
syll
Mean Difference
(I-J)
Std.
Error df Sig.a
95% Confidence Interval for
Differencea
Lower Bound
Upper
Bound
a 1 C O 53.552* 19.659 3254.318 .006 15.007 92.097
O C -53.552* 19.659 3254.318 .006 -92.097 -15.007
2 C O -28.963 19.001 3254.141 .128 -66.218 8.293
O C 28.963 19.001 3254.141 .128 -8.293 66.218
3 C O 97.315* 30.369 3254.043 .001 37.770 156.859
O C -97.315* 30.369 3254.043 .001 -156.859 -37.770
e 1 C O 28.515 22.322 3254.354 .202 -15.250 72.281
O C -28.515 22.322 3254.354 .202 -72.281 15.250
2 C O -68.950* 20.762 3254.082 .001 -109.658 -28.242
O C 68.950* 20.762 3254.082 .001 28.242 109.658
3 C O -47.094 37.526 3254.089 .210 -120.671 26.482
O C 47.094 37.526 3254.089 .210 -26.482 120.671
i 1 C O -42.813 32.486 3254.166 .188 -106.509 20.883
O C 42.813 32.486 3254.166 .188 -20.883 106.509
2 C O -9.683 24.840 3254.136 .697 -58.386 39.020
O C 9.683 24.840 3254.136 .697 -39.020 58.386
3 C O -55.391 31.367 3254.067 .078 -116.892 6.110
O C 55.391 31.367 3254.067 .078 -6.110 116.892
o 1 C O 76.876* 25.932 3254.270 .003 26.030 127.722
O C -76.876* 25.932 3254.270 .003 -127.722 -26.030
2 C O 11.343 27.581 3254.055 .681 -42.735 65.421
O C -11.343 27.581 3254.055 .681 -65.421 42.735
3 C O 3.021 31.693 3254.067 .924 -59.120 65.161
383
O C -3.021 31.693 3254.067 .924 -65.161 59.120
u 1 C O 52.441 55.854 3254.514 .348 -57.071 161.953
O C -52.441 55.854 3254.514 .348 -161.953 57.071
2 C O -15.312 26.450 3254.047 .563 -67.172 36.549
O C 15.312 26.450 3254.047 .563 -36.549 67.172
3 C O 124.050* 29.804 3254.115 .000 65.614 182.486
O C -124.050* 29.804 3254.115 .000 -182.486 -65.614 Based on estimated marginal means. *. The mean difference is significant at the .05 level. a. Adjustment for multiple comparisons: Bonferroni. b. Dependent Variable: F2.
9) Pairwise comparisons of the significant interaction between vowel and course level. In the table, the variable is labeled as “group.” The “1” represents the intermediate-level HS, and “2” denotes the advanced-level group.
Pairwise Comparisonsb
vowel
(I)
Group
(J)
Group
Mean Difference
(I-J)
Std.
Error df Sig.a
95% Confidence Interval for
Differencea
Lower Bound
Upper
Bound
a 1 2 7.229 60.659 8.789 .908 -130.494 144.951
2 1 -7.229 60.659 8.789 .908 -144.951 130.494
e 1 2 -17.580 61.070 9.030 .780 -155.660 120.500
2 1 17.580 61.070 9.030 .780 -120.500 155.660
i 1 2 -46.640 61.851 9.501 .469 -185.441 92.160
2 1 46.640 61.851 9.501 .469 -92.160 185.441
o 1 2 102.117 62.162 9.694 .132 -36.985 241.219
2 1 -102.117 62.162 9.694 .132 -241.219 36.985
u 1 2 156.644* 62.592 9.964 .031 17.112 296.175
2 1 -156.644* 62.592 9.964 .031 -296.175 -17.112
Based on estimated marginal means
*. The mean difference is significant at the .05 level.
a. Adjustment for multiple comparisons: Bonferroni.
b. Dependent Variable: F2.
384
10) Pairwise comparisons of the significant interaction between vowel and travel group. The “0” refers to the “no travel” group, the “1” refers to the infrequent (every 3-4 years) travelers, and the “2” represents the frequent travel group.
Pairwise Comparisonsb
vowel
(I)
Travel
(J)
Travel
Mean Difference
(I-J)
Std.
Error df Sig.a
95% Confidence Interval for
Differencea
Lower Bound
Upper
Bound
a 0 1 -29.237 61.563 8.733 1.000 -211.041 152.567
2 -59.719 81.050 8.688 1.000 -299.352 179.914
1 0 29.237 61.563 8.733 1.000 -152.567 211.041
2 -30.482 74.444 8.698 1.000 -250.528 189.563
2 0 59.719 81.050 8.688 1.000 -179.914 299.352
1 30.482 74.444 8.698 1.000 -189.563 250.528
e 0 1 79.258 61.916 8.935 .698 -102.652 261.169
2 -93.428 81.580 8.918 .846 -333.215 146.360
1 0 -79.258 61.916 8.935 .698 -261.169 102.652
2 -172.686 74.840 8.884 .140 -392.845 47.474
2 0 93.428 81.580 8.918 .846 -146.360 333.215
1 172.686 74.840 8.884 .140 -47.474 392.845
i 0 1 -57.013 62.756 9.430 1.000 -239.269 125.243
2 -244.676* 82.469 9.313 .046 -484.812 -4.540
1 0 57.013 62.756 9.430 1.000 -125.243 239.269
2 -187.663 75.660 9.280 .103 -408.135 32.810
2 0 244.676* 82.469 9.313 .046 4.540 484.812
1 187.663 75.660 9.280 .103 -32.810 408.135
o 0 1 13.243 62.893 9.512 1.000 -169.082 195.568
2 79.067 83.403 9.742 1.000 -161.548 319.681
1 0 -13.243 62.893 9.512 1.000 -195.568 169.082
2 65.823 76.562 9.730 1.000 -155.106 286.753
2 0 -79.067 83.403 9.742 1.000 -319.681 161.548
1 -65.823 76.562 9.730 1.000 -286.753 155.106
u 0 1 5.385 63.619 9.959 1.000 -177.353 188.123
2 128.580 83.733 9.897 .468 -112.229 369.389
1 0 -5.385 63.619 9.959 1.000 -188.123 177.353
2 123.195 76.989 9.949 .422 -97.989 344.379
2 0 -128.580 83.733 9.897 .468 -369.389 112.229
385
1 -123.195 76.989 9.949 .422 -344.379 97.989
Based on estimated marginal means
*. The mean difference is significant at the .05 level.
a. Adjustment for multiple comparisons: Bonferroni.
b. Dependent Variable: F2.
11) Parameter estimates for the significant vowel by grammar score interaction. The [vowel=u]*grammar category was set to zero. The significance values indicate which vowels had slopes that differed significantly from zero.
95% Confidence
Interval
Parameter Estimat
e Std.
Error df t Sig. Lower Bound
Upper Bound
Grammar 16.887 11.709 9.999 1.442 0.180 -9.203 42.976 [vowel=a]*grammar -9.687 4.983 3254.072 -1.944 0.052 -19.459 0.083 [vowel=e]*grammar -27.475 5.118 3254.076 -5.368 0.000 -37.511 17.438 [vowel=i]*grammar -33.217 5.436 3254.071 -6.110 0.000 -43.876 22.557 [vowel=o]*grammar 7.487 5.602 3254.032 1.336 0.181 -3.497 18.472 [vowel=u]*grammar 0 0 . . . . .
12) Parameter estimates for the significant vowel by Spanish use interaction. The [vowel=u]*Spanish use category was set to zero. The significance values indicate which vowels had slopes that differed significantly from zero.
95% Confidence
Interval
Parameter Estimate Std.
Error df t Sig. Lower Bound
Upper Bound
Spanish use -23.047 8.294 10.020 -2.779 0.019 -41.522 -4.572 [vowel=a]*Spanish use 18.518 3.488 3254.149 5.309 0.000 11.678 25.358 [vowel=e]*Spanish use 24.915 3.600 3254.298 6.920 0.000 17.855 31.975 [vowel=i]*Spanish use 38.389 3.803 3254.185 0.109 0.000 30.931 45.847 [vowel=o]*Spanish use 10.264 3.967 3254.149 2.587 0.010 2.485 18.042 [vowel=u]*Spanish use 0 0 . . . . .
386
Appendix J: Results of statistical analyses conducted with Euclidean distance.
1) Table of Type II Tests of Fixed Effects indicates which main effects and interactions were significant.
Type III Tests of Fixed Effectsa
Source Numerator df Denominator df F Sig.
Intercept 1 7.973 2.249 .172
vowel 4 3254.148 5.066 .000
task 2 3254.730 89.789 .000
stress 1 3254.393 190.064 .000
syll 1 3254.228 35.296 .000
Gender 1 8.002 15.168 .005
Group 1 8.013 1.865 .209
Travel 2 7.991 2.758 .123
Grammar 1 8.014 3.029 .120
ICCSTotal 1 7.978 .026 .877
Spanuse 1 7.998 4.156 .076
vowel * task 8 3254.264 6.165 .000
vowel * stress 4 3254.300 25.014 .000
vowel * syll 4 3254.172 .815 .515
vowel * task * stress 10 3254.326 14.744 .000
vowel * task * syll 10 3254.192 4.089 .000
vowel * Gender 4 3254.185 20.543 .000
vowel * Group 4 3254.133 8.988 .000
vowel * Travel 8 3254.143 10.775 .000
vowel * Grammar 4 3254.055 4.257 .002
vowel * ICCSTotal 4 3254.145 4.830 .001
vowel * Spanuse 4 3254.149 16.695 .000
a. Dependent Variable: EUC.
387
2) Pairwise comparisons of the main effect of vowel, which indicates which vowels differ statistically from each other.
Pairwise Comparisonsb
(I) vowel (J) vowel
Mean
Difference (I-
J) Std. Error df Sig.a
95% Confidence Interval for
Differencea
Lower Bound
Upper
Bound
a e -37.226* 11.593 3254.046 .013 -69.791 -4.660
i -333.997* 12.376 3254.235 .000 -368.759 -299.234
o -250.056* 11.924 3254.431 .000 -283.549 -216.563
u -222.637* 14.185 3254.226 .000 -262.483 -182.792
e a 37.226* 11.593 3254.046 .013 4.660 69.791
i -296.771* 12.903 3254.121 .000 -333.015 -260.527
o -212.830* 12.474 3254.409 .000 -247.869 -177.792
u -185.412* 14.651 3254.206 .000 -226.565 -144.259
i a 333.997* 12.376 3254.235 .000 299.234 368.759
e 296.771* 12.903 3254.121 .000 260.527 333.015
o 83.941* 13.206 3254.591 .000 46.845 121.036
u 111.359* 15.269 3254.116 .000 68.470 154.248
o a 250.056* 11.924 3254.431 .000 216.563 283.549
e 212.830* 12.474 3254.409 .000 177.792 247.869
i -83.941* 13.206 3254.591 .000 -121.036 -46.845
u 27.419 14.915 3254.480 .661 -14.477 69.315
u a 222.637* 14.185 3254.226 .000 182.792 262.483
e 185.412* 14.651 3254.206 .000 144.259 226.565
i -111.359* 15.269 3254.116 .000 -154.248 -68.470
o -27.419 14.915 3254.480 .661 -69.315 14.477
Based on estimated marginal means
*. The mean difference is significant at the .05 level.
a. Adjustment for multiple comparisons: Bonferroni.
b. Dependent Variable: EUC.
388
3) Pairwise comparisons of the main effect of task (speech style). “1” represents the
NRT, “2” the PIT, and “3” the CPT.
Pairwise Comparisonsb
(I) task (J) task
Mean
Difference (I-J) Std. Error df Sig.a
95% Confidence Interval
for Differencea
Lower
Bound
Upper
Bound
1 2 -16.744 7.596 3255.153 .083 -34.937 1.449
3 -105.099* 8.778 3254.837 .000 -126.123 -84.074
2 1 16.744 7.596 3255.153 .083 -1.449 34.937
3 -88.355* 7.488 3254.236 .000 -106.291 -70.418
3 1 105.099* 8.778 3254.837 .000 84.074 126.123
2 88.355* 7.488 3254.236 .000 70.418 106.291
Based on estimated marginal means
a. Adjustment for multiple comparisons: Bonferroni.
*. The mean difference is significant at the .05 level.
b. Dependent Variable: EUC.
4) Pairwise comparisons of the main effect of stress. “T” indicates tonic, and “A” indicates atonic.
Pairwise Comparisonsb
(I)
stress
(J)
stress
Mean Difference (I-
J)
Std.
Error df Sig.a
95% Confidence Interval for
Differencea
Lower Bound Upper Bound
A T -81.722* 5.928 3254.393 .000 -93.344 -70.099
T A 81.722* 5.928 3254.393 .000 70.099 93.344
Based on estimated marginal means
*. The mean difference is significant at the .05 level.
a. Adjustment for multiple comparisons: Bonferroni.
b. Dependent Variable: EUC.
389
5) Pairwise comparisons of the main effect of syllable type. “C” indicates a closed syllable, and “O” indicates an open syllable.
Pairwise Comparisonsb
(I) syll (J) syll
Mean
Difference (I-J) Std. Error df Sig.a
95% Confidence Interval
for Differencea
Lower
Bound
Upper
Bound
C O -37.567* 6.323 3254.228 .000 -49.965 -25.169
O C 37.567* 6.323 3254.228 .000 25.169 49.965
Based on estimated marginal means
*. The mean difference is significant at the .05 level.
a. Adjustment for multiple comparisons: Bonferroni.
b. Dependent Variable: EUC.
6) Pairwise comparisons of the significant vowel by task interaction.
Pairwise Comparisonsb
vowel
(I)
task
(J)
task
Mean Difference
(I-J)
Std.
Error df Sig.a
95% Confidence Interval for
Differencea
Lower Bound Upper Bound
a 1 2 -22.631 11.310 3254.175 .136 -49.720 4.458
3 -73.614* 15.518 3254.064 .000 -110.782 -36.446
2 1 22.631 11.310 3254.175 .136 -4.458 49.720
3 -50.983* 15.242 3254.070 .002 -87.490 -14.476
3 1 73.614* 15.518 3254.064 .000 36.446 110.782
2 50.983* 15.242 3254.070 .002 14.476 87.490
e 1 2 -2.436 12.225 3254.779 1.000 -31.719 26.846
3 -186.562* 18.595 3254.399 .000 -231.102 -142.022
2 1 2.436 12.225 3254.779 1.000 -26.846 31.719
3 -184.126* 17.877 3254.083 .000 -226.944 -141.307
3 1 186.562* 18.595 3254.399 .000 142.022 231.102
2 184.126* 17.877 3254.083 .000 141.307 226.944
i 1 2 -58.649* 16.855 3254.405 .002 -99.020 -18.277
3 -132.501* 19.933 3254.349 .000 -180.245 -84.757
2 1 58.649* 16.855 3254.405 .002 18.277 99.020
390
3 -73.852* 17.821 3254.096 .000 -116.539 -31.166
3 1 132.501* 19.933 3254.349 .000 84.757 180.245
2 73.852* 17.821 3254.096 .000 31.166 116.539
o 1 2 -27.112 15.354 3254.711 .233 -63.889 9.665
3 -84.733* 15.311 3254.715 .000 -121.405 -48.061
2 1 27.112 15.354 3254.711 .233 -9.665 63.889
3 -57.621* 15.638 3254.113 .001 -95.078 -20.165
3 1 84.733* 15.311 3254.715 .000 48.061 121.405
2 57.621* 15.638 3254.113 .001 20.165 95.078
u 1 2 27.108 25.322 3254.765 .853 -33.543 87.760
3 -48.084 26.537 3254.674 .210 -111.645 15.477
2 1 -27.108 25.322 3254.765 .853 -87.760 33.543
3 -75.192* 16.931 3254.067 .000 -115.746 -34.637
3 1 48.084 26.537 3254.674 .210 -15.477 111.645
2 75.192* 16.931 3254.067 .000 34.637 115.746 Based on estimated marginal means a. Adjustment for multiple comparisons: Bonferroni. *. The mean difference is significant at the .05 level. b. Dependent Variable: EUC 7) Pairwise comparisons of the vowel by stress interaction.
Pairwise Comparisons
vowel
(I)
stress
(J)
stress
Mean Difference
(I-J) Std. Error df Sig.a
95% Confidence Interval
for Differencea
Lower
Bound
Upper
Bound
a A T -50.087* 11.419 3254.172 .000 -72.476 -27.698
T A 50.087* 11.419 3254.172 .000 27.698 72.476
e A T .309 13.065 3254.350 .981 -25.307 25.926
T A -.309 13.065 3254.350 .981 -25.926 25.307
i A T -179.805* 13.634 3254.286 .000 -206.537 -153.073
T A 179.805* 13.634 3254.286 .000 153.073 206.537
o A T -98.057* 13.182 3254.496 .000 -123.902 -72.212
T A 98.057* 13.182 3254.496 .000 72.212 123.902
u A T -80.970* 14.742 3254.302 .000 -109.874 -52.065
T A 80.970* 14.742 3254.302 .000 52.065 109.874 Dependent variables: Euc. Based on estimated marginal means a. Adjustment for multiple comparisons: Bonferroni. *. The mean difference is significant at the .05 level.
391
8) Pairwise comparisons of the significant interaction between vowel, task, and stress. The 1,2,3 stand for the NRT, PIT, and CPT respectively. “T” denotes tonic, and “A” denotes atonic.
Pairwise Comparisonsb
vowel task
(I)
stress
(J)
stress
Mean
Difference (I-J)
Std.
Error df Sig.a
95% Confidence Interval
for Differencea
Lower
Bound
Upper
Bound
a 1 A T -87.647* 15.415 3254.437 .000 -117.870 -57.423
T A 87.647* 15.415 3254.437 .000 57.423 117.870
2 A T -50.999* 15.311 3254.111 .001 -81.019 -20.979
T A 50.999* 15.311 3254.111 .001 20.979 81.019
3 A T -11.616 26.516 3254.200 .661 -63.606 40.374
T A 11.616 26.516 3254.200 .661 -40.374 63.606
e 1 A T -108.864* 16.854 3254.321 .000 -141.908 -75.819
T A 108.864* 16.854 3254.321 .000 75.819 141.908
2 A T -95.096* 16.522 3254.120 .000 -127.491 -62.701
T A 95.096* 16.522 3254.120 .000 62.701 127.491
3 A T 204.888* 31.272 3254.161 .000 143.573 266.202
T A -204.888* 31.272 3254.161 .000 -266.202 -143.573
i 1 A T -218.370* 22.337 3255.147 .000 -262.167 -174.573
T A 218.370* 22.337 3255.147 .000 174.573 262.167
2 A T -72.890* 19.552 3254.121 .000 -111.225 -34.554
T A 72.890* 19.552 3254.121 .000 34.554 111.225
3 A T -248.156* 28.168 3254.006 .000 -303.384 -192.928
T A 248.156* 28.168 3254.006 .000 192.928 303.384
o 1 A T -66.230* 20.960 3255.396 .002 -107.326 -25.134
T A 66.230* 20.960 3255.396 .002 25.134 107.326
2 A T -99.129* 21.180 3254.183 .000 -140.657 -57.601
T A 99.129* 21.180 3254.183 .000 57.601 140.657
3 A T -128.811* 26.006 3254.020 .000 -179.801 -77.822
T A 128.811* 26.006 3254.020 .000 77.822 179.801
u 1 A T -6.301 31.161 3254.554 .840 -67.398 54.796
T A 6.301 31.161 3254.554 .840 -54.796 67.398
2 A T -150.489* 19.811 3254.040 .000 -189.331 -111.646
T A 150.489* 19.811 3254.040 .000 111.646 189.331
3 A T -86.120* 24.374 3254.068 .000 -133.909 -38.330
392
T A 86.120* 24.374 3254.068 .000 38.330 133.909 Based on estimated marginal means a. Adjustment for multiple comparisons: Bonferroni. *. The mean difference is significant at the .05 level. b. Dependent Variable: EUC
9) Interaction between vowel, task, and syllable type. The “C” stands for closed (syllable) and the “O” for open (syllable). The numbers 1, 2, 3 stand for the NRT, PIT, and CPT respectively.
Pairwise Comparisonsb
vowel task (I) syll (J) syll
Mean
Difference (I-
J)
Std.
Error df Sig.a
95% Confidence Interval
for Differencea
Lower
Bound
Upper
Bound
a 1 C O -47.365* 15.886 3254.405 .003 -78.513 -16.218
O C 47.365* 15.886 3254.405 .003 16.218 78.513
2 C O 19.395 15.355 3254.156 .207 -10.710 49.501
O C -19.395 15.355 3254.156 .207 -49.501 10.710
3 C O -42.001 24.541 3254.016 .087 -90.118 6.115
O C 42.001 24.541 3254.016 .087 -6.115 90.118
e 1 C O -7.277 18.038 3254.456 .687 -42.643 28.089
O C 7.277 18.038 3254.456 .687 -28.089 42.643
2 C O -41.643* 16.777 3254.071 .013 -74.539 -8.748
O C 41.643* 16.777 3254.071 .013 8.748 74.539
3 C O -54.032 30.324 3254.081 .075 -113.488 5.424
O C 54.032 30.324 3254.081 .075 -5.424 113.488
i 1 C O -62.912* 26.252 3254.191 .017 -114.384 -11.441
O C 62.912* 26.252 3254.191 .017 11.441 114.384
2 C O -5.194 20.072 3254.149 .796 -44.550 34.161
O C 5.194 20.072 3254.149 .796 -34.161 44.550
3 C O -53.062* 25.347 3254.050 .036 -102.760 -3.364
O C 53.062* 25.347 3254.050 .036 3.364 102.760
o 1 C O -69.197* 20.955 3254.337 .001 -110.284 -28.110
O C 69.197* 20.955 3254.337 .001 28.110 110.284
2 C O -9.843 22.288 3254.034 .659 -53.543 33.857
O C 9.843 22.288 3254.034 .659 -33.857 53.543
3 C O -10.078 25.611 3254.050 .694 -60.292 40.137
O C 10.078 25.611 3254.050 .694 -40.137 60.292
393
u 1 C O -81.829 45.134 3254.679 .070 -170.323 6.664
O C 81.829 45.134 3254.679 .070 -6.664 170.323
2 C O 19.987 21.374 3254.021 .350 -21.921 61.895
O C -19.987 21.374 3254.021 .350 -61.895 21.921
3 C O -118.448* 24.084 3254.118 .000 -165.669 -71.227
O C 118.448* 24.084 3254.118 .000 71.227 165.669 Based on estimated marginal means a. Adjustment for multiple comparisons: Bonferroni. *. The mean difference is significant at the .05 level. b. Dependent Variable: EUC 10) Pairwise comparisons of the significant interaction between vowel and course level. In the table, the variable is labeled as “group.” The “1” represents the intermediate-level HS, and “2” denotes the advanced-level group.
Pairwise Comparisonsb
vowel (I) Group (J) Group
Mean
Difference
(I-J)
Std.
Error df Sig.a
95% Confidence Interval
for Differencea
Lower
Bound
Upper
Bound
a 1 2 9.590 41.619 9.076 .823 -84.438 103.618
2 1 -9.590 41.619 9.076 .823 -103.618 84.438
e 1 2 -47.844 42.009 9.422 .283 -142.231 46.544
2 1 47.844 42.009 9.422 .283 -46.544 142.231
i 1 2 -69.180 42.749 10.103 .136 -164.300 25.940
2 1 69.180 42.749 10.103 .136 -25.940 164.300
o 1 2 -60.035 43.043 10.383 .192 -155.463 35.393
2 1 60.035 43.043 10.383 .192 -35.393 155.463
u 1 2 -108.008* 43.448 10.779 .031 -203.874 -12.141
2 1 108.008* 43.448 10.779 .031 12.141 203.874 Based on estimated marginal means a. Adjustment for multiple comparisons: Bonferroni. *. The mean difference is significant at the .05 level. b. Dependent Variable: EUC
394
11) Pairwise comparisons of the significant interaction between vowel and travel frequency. The “0” denotes those who did not travel, the “1” those who traveled every 3-4 years, and the “2” represents the frequent travelers.
Pairwise Comparisonsb
vowel (I) Travel (J) Travel
Mean Difference
(I-J)
Std.
Error df Sig.a
95% Confidence Interval
for Differencea
Lower
Bound
Upper
Bound
a 0 1 30.360 42.212 8.995 1.000 -93.478 154.197
2 -11.091 55.547 8.931 1.000 -174.303 152.122
1 0 -30.360 42.212 8.995 1.000 -154.197 93.478
2 -41.450 51.025 8.945 1.000 -191.325 108.424
2 0 11.091 55.547 8.931 1.000 -152.122 174.303
1 41.450 51.025 8.945 1.000 -108.424 191.325
e 0 1 57.879 42.548 9.284 .617 -66.093 181.851
2 -63.762 56.051 9.260 .852 -227.169 99.646
1 0 -57.879 42.548 9.284 .617 -181.851 66.093
2 -121.641 51.402 9.212 .125 -271.659 28.377
2 0 63.762 56.051 9.260 .852 -99.646 227.169
1 121.641 51.402 9.212 .125 -28.377 271.659
i 0 1 -49.387 43.344 9.999 .843 -173.790 75.016
2 -203.037* 56.894 9.829 .016 -366.880 -39.194
1 0 49.387 43.344 9.999 .843 -75.016 173.790
2 -153.650* 52.179 9.782 .045 -304.060 -3.240
2 0 203.037* 56.894 9.829 .016 39.194 366.880
1 153.650* 52.179 9.782 .045 3.240 304.060
o 0 1 -23.341 43.474 10.119 1.000 -147.829 101.146
2 -113.063 57.776 10.453 .233 -277.495 51.368
1 0 23.341 43.474 10.119 1.000 -101.146 147.829
2 -89.722 53.032 10.437 .361 -240.695 61.251
2 0 113.063 57.776 10.453 .233 -51.368 277.495
1 89.722 53.032 10.437 .361 -61.251 240.695
u 0 1 -10.611 44.159 10.772 1.000 -135.603 114.381
2 -161.487 58.087 10.680 .055 -326.156 3.181
1 0 10.611 44.159 10.772 1.000 -114.381 135.603
2 -150.877 53.434 10.757 .051 -302.159 .406
2 0 161.487 58.087 10.680 .055 -3.181 326.156
395
1 150.877 53.434 10.757 .051 -.406 302.159
Based on estimated marginal means
a. Adjustment for multiple comparisons: Bonferroni.
*. The mean difference is significant at the .05 level.
b. Dependent Variable: EUC.
11) Parameter estimates for the significant vowel by grammar score interaction. The [vowel=u]*grammar total category was set to zero. The significance values indicate which vowels had slopes that differed significantly from zero.
95% Confidence
Interval
Parameter Estimate Std.
Error df t Sig. Lower Bound
Upper Bound
Grammar -10.788 8.130 10.830 -1.327 0.212 -28.716 7.141 [vowel=a]*grammar 4.983 4.027 3254.057 1.238 0.216 -2.912 12.879 [vowel=e]*grammar -1.179 4.136 3254.063 -0.285 0.775 -9.290 6.930 [vowel=i]*grammar -8.542 4.393 3254.056 -1.944 0.052 -17.155 0.072 [vowel=o]*grammar -6.935 4.527 3254.001 -1.532 0.126 -15.812 1.941 [vowel=u]*grammar 0 0 . . . . .
12) Parameter estimates for the significant vowel by cultural sensitivity interaction (ICCS total). The [vowel=u]*ICCS total category was set to zero. The significance values indicate which vowels had slopes that differed significantly from zero.
95% Confidence
Interval
Parameter Estimate Std. Error df t Sig.
Lower Bound
Upper Bound
ICCS total 0.386 1.410 10.630 0.274 0.789 -2.730 3.503 [vowel=a]*ICCS total 0.150 0.679 3254.055 0.222 0.825 -1.182 1.483 [vowel=e]*ICCS total -1.363 0.703 3254.116 -1.938 0.053 -2.743 0.016 [vowel=i]*ICCS total -2.002 0.737 3254.034 -2.717 0.007 -3.448 -0.557 [vowel=o]*ICCS total 0.234 0.749 3254.286 0.313 0.754 -1.234 1.704 [vowel=u]*ICCS total 0 0 . . . . .
396
13) Parameter estimates for the significant vowel by Spanish use. The [vowel=u]*Spanuse category was set to zero. The significance values indicate which vowels had slopes that differed significantly from zero.
95% Confidence
Interval
Parameter Estimate Std. Error df t Sig.
Lower Bound
Upper Bound
Spanish use 16.071 5.760 10.860 2.790 0.018 3.374 28.769 [vowel=a]*Spanish use -14.472 2.828 3254.166 5.134 0.000 -19.999 -8.945 [vowel=e]*Spanish use -6.879 2.909 3254.377 2.364 0.018 -12.583 -1.170 [vowel=i]*Spanish use 4.669 3.073 3254.217 1.518 0.129 -1.359 10.693 [vowel=o]*Spanish use -9.281 3.205 3254.166 2.895 0.004 -15.567 -2.999 [vowel=u]*Spanish use 0 0 . . . . .
397
Appendix K: Results of statistical analyses conducted with duration.
1) Table of Type II Tests of Fixed Effects indicates which main effects and interactions were significant.
Type III Tests of Fixed Effectsa
Source Numerator df Denominator df F Sig.
Intercept 1 8.040 4.125 .077
vowel 4 3254.166 3.803 .004
task 2 3254.769 13.390 .000
stress 1 3254.419 749.661 .000
syll 1 3254.248 9.310 .002
Gender 1 8.070 1.684 .230
Group 1 8.082 1.248 .296
Travel 2 8.058 .608 .567
Grammar 1 8.083 .819 .392
ICCSTotal 1 8.045 .001 .975
Spanuse 1 8.066 .222 .650
vowel * task 8 3254.286 5.953 .000
vowel * stress 4 3254.323 7.252 .000
vowel * syll 4 3254.191 4.281 .002
vowel * task * stress 10 3254.350 1.517 .127
vowel * task * syll 10 3254.211 3.247 .000
vowel * Gender 4 3254.204 .647 .629
vowel * Group 4 3254.150 .253 .908
vowel * Travel 8 3254.160 1.301 .238
vowel * Grammar 4 3254.069 .477 .753
vowel * ICCSTotal 4 3254.162 .761 .550
vowel * Spanuse 4 3254.166 1.313 .263
a. Dependent Variable: Duration.
398
2) Pairwise comparisons of the main effect of vowel, which indicates which vowels differ statistically from each other.
Pairwise Comparisonsb
(I) vowel (J) vowel
Mean
Difference (I-
J) Std. Error df Sig.a
95% Confidence Interval for
Differencea
Lower Bound Upper Bound
a e .011* .002 3254.060 .000 .006 .016
i .018* .002 3254.256 .000 .012 .023
o .010* .002 3254.459 .000 .004 .015
u .014* .002 3254.247 .000 .007 .020
e a -.011* .002 3254.060 .000 -.016 -.006
i .007* .002 3254.137 .005 .001 .013
o -.001 .002 3254.436 1.000 -.007 .004
u .003 .002 3254.226 1.000 -.004 .009
i a -.018* .002 3254.256 .000 -.023 -.012
e -.007* .002 3254.137 .005 -.013 -.001
o -.008* .002 3254.625 .001 -.014 -.003
u -.004 .002 3254.132 .856 -.011 .003
o a -.010* .002 3254.459 .000 -.015 -.004
e .001 .002 3254.436 1.000 -.004 .007
i .008* .002 3254.625 .001 .003 .014
u .004 .002 3254.510 .738 -.002 .011
u a -.014* .002 3254.247 .000 -.020 -.007
e -.003 .002 3254.226 1.000 -.009 .004
i .004 .002 3254.132 .856 -.003 .011
o -.004 .002 3254.510 .738 -.011 .002
Based on estimated marginal means
*. The mean difference is significant at the .05 level.
a. Adjustment for multiple comparisons: Bonferroni.
b. Dependent Variable: Duration.
399
3) Pairwise comparisons of the main effect of task (speech style). “1” represents the
NRT, “2” the PIT, and “3” the CPT.
Pairwise Comparisonsb
(I) task (J) task
Mean
Difference (I-J) Std. Error df Sig.a
95% Confidence Interval for
Differencea
Lower Bound Upper Bound
1 2 -.006* .001 3255.207 .000 -.008 -.003
3 -.006* .001 3254.879 .000 -.010 -.003
2 1 .006* .001 3255.207 .000 .003 .008
3 -.001 .001 3254.257 1.000 -.004 .002
3 1 .006* .001 3254.879 .000 .003 .010
2 .001 .001 3254.257 1.000 -.002 .004
Based on estimated marginal means
*. The mean difference is significant at the .05 level.
a. Adjustment for multiple comparisons: Bonferroni.
b. Dependent Variable: Duration.
4) Pairwise comparisons of the main effect of stress. “T” indicates tonic, and “A” indicates atonic.
Pairwise Comparisonsb
(I)
stress (J) stress
Mean
Difference (I-
J) Std. Error df Sig.a
95% Confidence Interval for
Differencea
Lower Bound Upper Bound
A T -.026* .001 3254.419 .000 -.028 -.024
T A .026* .001 3254.419 .000 .024 .028
Based on estimated marginal means
*. The mean difference is significant at the .05 level.
a. Adjustment for multiple comparisons: Bonferroni.
b. Dependent Variable: Duration.
400
5) Pairwise comparisons of the main effect of syllable type. “C” indicates a closed syllable, and “O” indicates an open syllable.
Pairwise Comparisonsb
(I) syll (J) syll
Mean
Difference (I-J) Std. Error df Sig.a
95% Confidence Interval for
Differencea
Lower Bound Upper Bound
C O .003* .001 3254.248 .002 .001 .005
O C -.003* .001 3254.248 .002 -.005 -.001
Based on estimated marginal means
*. The mean difference is significant at the .05 level.
a. Adjustment for multiple comparisons: Bonferroni.
b. Dependent Variable: Duration.
6) Pairwise comparisons of the significant vowel by task interaction.
Pairwise Comparisonsb
vowel
(I)
task
(J)
task
Mean Difference
(I-J)
Std.
Error df Sig.a
95% Confidence Interval for
Differencea
Lower Bound Upper Bound
a 1 2 -.010* .002 3254.194 .000 -.015 -.006
3 -.011* .002 3254.079 .000 -.017 -.005
2 1 .010* .002 3254.194 .000 .006 .015
3 -.001 .002 3254.085 1.000 -.007 .005
3 1 .011* .002 3254.079 .000 .005 .017
2 .001 .002 3254.085 1.000 -.005 .007
e 1 2 .002 .002 3254.820 .663 -.002 .007
3 .000 .003 3254.426 1.000 -.007 .007
2 1 -.002 .002 3254.820 .663 -.007 .002
3 -.002 .003 3254.098 1.000 -.009 .005
3 1 .000 .003 3254.426 1.000 -.007 .007
2 .002 .003 3254.098 1.000 -.005 .009
i 1 2 -.001 .003 3254.432 1.000 -.007 .006
3 -.002 .003 3254.374 1.000 -.010 .005
2 1 .001 .003 3254.432 1.000 -.006 .007
401
3 -.001 .003 3254.111 1.000 -.008 .005
3 1 .002 .003 3254.374 1.000 -.005 .010
2 .001 .003 3254.111 1.000 -.005 .008
o 1 2 -.014* .002 3254.750 .000 -.020 -.008
3 -.016* .002 3254.753 .000 -.022 -.010
2 1 .014* .002 3254.750 .000 .008 .020
3 -.002 .002 3254.129 1.000 -.008 .004
3 1 .016* .002 3254.753 .000 .010 .022
2 .002 .002 3254.129 1.000 -.004 .008
u 1 2 -.005 .004 3254.805 .620 -.015 .005
3 -.003 .004 3254.711 1.000 -.013 .007
2 1 .005 .004 3254.805 .620 -.005 .015
3 .002 .003 3254.081 1.000 -.005 .008
3 1 .003 .004 3254.711 1.000 -.007 .013
2 -.002 .003 3254.081 1.000 -.008 .005
Based on estimated marginal means
*. The mean difference is significant at the .05 level.
a. Adjustment for multiple comparisons: Bonferroni.
b. Dependent Variable: Duration.
7) Pairwise comparisons of the vowel by syllable type interaction.
Pairwise Comparisonsb
vowel
(I)
syll
(J)
syll
Mean Difference
(I-J)
Std.
Error df Sig.a
95% Confidence Interval for
Differencea
Lower Bound Upper Bound
a C O -7.444E-5 .002 3254.186 .966 -.003 .003
O C 7.444E-5 .002 3254.186 .966 -.003 .003
e C O .006* .002 3254.218 .005 .002 .010
O C -.006* .002 3254.218 .005 -.010 -.002
i C O .010* .002 3254.086 .000 .005 .014
O C -.010* .002 3254.086 .000 -.014 -.005
o C O .002 .002 3254.223 .285 -.002 .006
O C -.002 .002 3254.223 .285 -.006 .002
u C O -.002 .003 3254.332 .444 -.008 .003
O C .002 .003 3254.332 .444 -.003 .008
402
Pairwise Comparisonsb
vowel
(I)
syll
(J)
syll
Mean Difference
(I-J)
Std.
Error df Sig.a
95% Confidence Interval for
Differencea
Lower Bound Upper Bound
a C O -7.444E-5 .002 3254.186 .966 -.003 .003
O C 7.444E-5 .002 3254.186 .966 -.003 .003
e C O .006* .002 3254.218 .005 .002 .010
O C -.006* .002 3254.218 .005 -.010 -.002
i C O .010* .002 3254.086 .000 .005 .014
O C -.010* .002 3254.086 .000 -.014 -.005
o C O .002 .002 3254.223 .285 -.002 .006
O C -.002 .002 3254.223 .285 -.006 .002
u C O -.002 .003 3254.332 .444 -.008 .003
O C .002 .003 3254.332 .444 -.003 .008
Based on estimated marginal means
*. The mean difference is significant at the .05 level.
a. Adjustment for multiple comparisons: Bonferroni.
b. Dependent Variable: Duration.
8) Pairwise comparisons of the significant interaction between vowel, task, and stress. The 1,2,3 stand for the NRT, PIT, and CPT respectively. “T” denotes tonic, and “A” denotes atonic.
Pairwise Comparisonsb
vowel task
(I)
stress
(J)
stress
Mean Difference
(I-J)
Std.
Error df
Sig.a
95% Confidence Interval
for Differencea
Lower
Bound
Upper
Bound
a 1 A T -.028* .002 3254.465 .000 -.033 -.023
T A .028* .002 3254.465 .000 .023 .033
2 A T -.028* .002 3254.127 .000 -.033 -.024
T A .028* .002 3254.127 .000 .024 .033
3 A T -.030* .004 3254.219 .000 -.038 -.022
T A .030* .004 3254.219 .000 .022 .038
e 1 A T -.030* .003 3254.344 .000 -.035 -.025
T A .030* .003 3254.344 .000 .025 .035
403
2 A T -.027* .003 3254.136 .000 -.032 -.022
T A .027* .003 3254.136 .000 .022 .032
3 A T -.032* .005 3254.179 .000 -.042 -.023
T A .032* .005 3254.179 .000 .023 .042
i 1 A T -.020* .004 3255.200 .000 -.027 -.013
T A .020* .004 3255.200 .000 .013 .027
2 A T -.013* .003 3254.137 .000 -.019 -.006
T A .013* .003 3254.137 .000 .006 .019
3 A T -.015* .004 3254.018 .001 -.024 -.006
T A .015* .004 3254.018 .001 .006 .024
o 1 A T -.022* .003 3255.458 .000 -.028 -.015
T A .022* .003 3255.458 .000 .015 .028
2 A T -.033* .003 3254.201 .000 -.040 -.027
T A .033* .003 3254.201 .000 .027 .040
3 A T -.027* .004 3254.033 .000 -.035 -.019
T A .027* .004 3254.033 .000 .019 .035
u 1 A T -.019* .005 3254.587 .000 -.029 -.009
T A .019* .005 3254.587 .000 .009 .029
2 A T -.033* .003 3254.054 .000 -.039 -.026
T A .033* .003 3254.054 .000 .026 .039
3 A T -.028* .004 3254.083 .000 -.036 -.021
T A .028* .004 3254.083 .000 .021 .036 Based on estimated marginal means *. The mean difference is significant at the .05 level. a. Adjustment for multiple comparisons: Bonferroni. b. Dependent variable: Duration 9) Interaction between vowel, task, and syllable type. The “C” stands for closed (syllable) and the “O” for open (syllable). The numbers 1, 2, 3 stand for the NRT, PIT, and CPT respectively.
Pairwise Comparisonsb
vowel task
(I)
syll
(J)
syll
Mean Difference
(I-J)
Std.
Error df Sig.a
95% Confidence Interval for
Differencea
Lower Bound Upper Bound
a 1 C O .001 .003 3254.432 .708 -.004 .006
O C -.001 .003 3254.432 .708 -.006 .004
2 C O -.004 .002 3254.173 .137 -.008 .001
404
O C .004 .002 3254.173 .137 -.001 .008
3 C O .002 .004 3254.028 .529 -.005 .010
O C -.002 .004 3254.028 .529 -.010 .005
e 1 C O .009* .003 3254.485 .001 .004 .015
O C -.009* .003 3254.485 .001 -.015 -.004
2 C O .002 .003 3254.086 .488 -.003 .007
O C -.002 .003 3254.086 .488 -.007 .003
3 C O .006 .005 3254.096 .197 -.003 .016
O C -.006 .005 3254.096 .197 -.016 .003
i 1 C O .011* .004 3254.210 .006 .003 .020
O C -.011* .004 3254.210 .006 -.020 -.003
2 C O .017* .003 3254.166 .000 .011 .023
O C -.017* .003 3254.166 .000 -.023 -.011
3 C O -1.481E-5 .004 3254.064 .997 -.008 .008
O C 1.481E-5 .004 3254.064 .997 -.008 .008
o 1 C O .002 .003 3254.362 .497 -.004 .009
O C -.002 .003 3254.362 .497 -.009 .004
2 C O .007 .004 3254.047 .055 .000 .014
O C -.007 .004 3254.047 .055 -.014 .000
3 C O -.002 .004 3254.064 .577 -.010 .006
O C .002 .004 3254.064 .577 -.006 .010
u 1 C O -.008 .007 3254.716 .282 -.022 .006
O C .008 .007 3254.716 .282 -.006 .022
2 C O .009* .003 3254.034 .009 .002 .015
O C -.009* .003 3254.034 .009 -.015 -.002
3 C O -.008* .004 3254.134 .040 -.015 .000
O C .008* .004 3254.134 .040 .000 .015 Based on estimated marginal means. *. The mean difference is significant at the .05 level. a. Adjustment for multiple comparisons: Bonferroni. b. Dependent variable: Duration
405
Appendix L: Normalized and non-normalized formant values
Comparison of statistical results conducted on normalized and non-normalized values. The darkened cells indicate differences between the two statistical outcomes.
Vowel 0.000 0.000 0.000 0.000 0.000 0.000 0.004Task 0.000 0.000 0.002 0.003 0.000 0.000 0.000Stress 0.000 0.000 0.000 0.000 0.000Syllable Type 0.000 0.000 0.002Vowel*Task 0.000 0.000 0.000 0.000 0.000 0.000 0.000Vowel*Stress 0.000 0.000 0.000 0.000 0.000 0.000 0.000
Vowel*Syllable Type 0.000 0.000 0.000 0.002
Vowel*Task*Stress 0.004 0.004 0.000 0.000 0.000 0.000
Vowel*Task*Syllable Type 0.000 0.000 0.000 0.000 0.000 0.000 0.000
Gender 0.025 0.005LevelTravelGrammarICCS TotalSpanish UseVowel*Gender 0.000 0.000 0.000 0.000 0.027Vowel*Level 0.046 0.000 0.001 0.000 0.011Vowel*Travel 0.000 0.000 0.000 0.000 0.000 0.000Vowel*Grammar 0.000 0.000 0.000 0.002Vowel*ICCS Total 0.022 0.006 0.001 0.001Vowel*Spanish Use 0.000 0.000 0.033 0.000 0.001
Effect/InteractionNormalized
F1F1 F2Normalized
F2Euclidean Distance
Normalized Euclidean Distance
Duration
406
Appendix M: Vowel by task by travel interaction
1) Type III tests of fixed effects: Dependent variable F1.
Type III Tests of Fixed Effectsa
Source Numerator df Denominator df F Sig.
Intercept 1 7.990 19.335 .002
vowel 4 3234.081 16.014 .000
task 2 3234.352 27.277 .000
stress 1 3234.226 215.545 .000
syll 1 3234.128 2.100 .147
Gender 1 8.005 7.707 .024
Group 1 8.011 .903 .370
Travel 2 8.008 2.666 .130
Grammar 1 8.011 .012 .914
ICCSTotal 1 7.992 1.480 .259
Spanuse 1 8.004 .478 .509
vowel * task 8 3234.129 25.177 .000
vowel * stress 4 3234.167 61.150 .000
vowel * syll 4 3234.090 .807 .521
vowel * task * stress 10 3234.178 2.494 .006
vowel * task * syll 10 3234.103 6.694 .000
vowel * Gender 4 3234.099 71.229 .000
vowel * Group 4 3234.073 2.762 .026
vowel * Travel 8 3234.088 20.770 .000
vowel * Grammar 4 3234.034 10.938 .000
vowel * ICCSTotal 4 3234.079 3.155 .013
vowel * Spanuse 4 3234.080 6.092 .000
vowel * task * Travel 20 3234.162 3.638 .000
a. Dependent Variable: F1.
407
2) Pairwise comparisons of interaction with dependent variable F1.
Pairwise Comparisonsb
vowel Travel (I) task
(J)
task
Mean
Difference
(I-J)
Std.
Error df Sig.a
95% Confidence
Interval for Differencea
Lower
Bound
Upper
Bound
a 0 1 2 8.845 7.917 3234.052 .792 -10.119 27.809
3 -24.486* 9.620 3234.002 .033 -47.528 -1.445
2 1 -8.845 7.917 3234.052 .792 -27.809 10.119
3 -33.332* 10.017 3234.012 .003 -57.325 -9.339
3 1 24.486* 9.620 3234.002 .033 1.445 47.528
2 33.332* 10.017 3234.012 .003 9.339 57.325
1 1 2 -9.341 7.381 3234.130 .617 -27.020 8.339
3 -55.862* 9.090 3234.096 .000 -77.633 -34.090
2 1 9.341 7.381 3234.130 .617 -8.339 27.020
3 -46.521* 8.938 3234.047 .000 -67.930 -25.112
3 1 55.862* 9.090 3234.096 .000 34.090 77.633
2 46.521* 8.938 3234.047 .000 25.112 67.930
2 1 2 -44.041* 7.233 3234.052 .000 -61.365 -26.717
3 -87.435* 8.678 3234.098 .000 -108.221 -66.648
2 1 44.041* 7.233 3234.052 .000 26.717 61.365
3 -43.394* 8.649 3234.039 .000 -64.111 -22.677
3 1 87.435* 8.678 3234.098 .000 66.648 108.221
2 43.394* 8.649 3234.039 .000 22.677 64.111
e 0 1 2 26.437* 8.468 3234.147 .005 6.155 46.720
3 52.785* 11.047 3234.054 .000 26.324 79.246
2 1 -26.437* 8.468 3234.147 .005 -46.720 -6.155
3 26.348 11.176 3234.029 .055 -.420 53.115
3 1 -52.785* 11.047 3234.054 .000 -79.246 -26.324
2 -26.348 11.176 3234.029 .055 -53.115 .420
1 1 2 48.158* 7.876 3234.426 .000 29.293 67.023
3 51.767* 10.604 3234.262 .000 26.368 77.167
2 1 -48.158* 7.876 3234.426 .000 -67.023 -29.293
3 3.610 10.026 3234.018 1.000 -20.406 27.625
3 1 -51.767* 10.604 3234.262 .000 -77.167 -26.368
408
2 -3.610 10.026 3234.018 1.000 -27.625 20.406
2 1 2 35.845* 7.911 3234.393 .000 16.896 54.793
3 36.723* 10.225 3234.266 .001 12.231 61.214
2 1 -35.845* 7.911 3234.393 .000 -54.793 -16.896
3 .878 9.859 3234.051 1.000 -22.737 24.493
3 1 -36.723* 10.225 3234.266 .001 -61.214 -12.231
2 -.878 9.859 3234.051 1.000 -24.493 22.737
i 0 1 2 21.292 11.354 3234.124 .183 -5.902 48.487
3 47.448* 12.025 3234.051 .000 18.647 76.249
2 1 -21.292 11.354 3234.124 .183 -48.487 5.902
3 26.156 11.463 3234.022 .068 -1.302 53.613
3 1 -47.448* 12.025 3234.051 .000 -76.249 -18.647
2 -26.156 11.463 3234.022 .068 -53.613 1.302
1 1 2 31.263* 10.718 3234.280 .011 5.592 56.934
3 69.969* 11.640 3234.294 .000 42.088 97.849
2 1 -31.263* 10.718 3234.280 .011 -56.934 -5.592
3 38.706* 10.127 3234.117 .000 14.450 62.961
3 1 -69.969* 11.640 3234.294 .000 -97.849 -42.088
2 -38.706* 10.127 3234.117 .000 -62.961 -14.450
2 1 2 34.251* 10.046 3234.110 .002 10.188 58.314
3 45.588* 10.837 3234.292 .000 19.631 71.544
2 1 -34.251* 10.046 3234.110 .002 -58.314 -10.188
3 11.337 9.946 3234.071 .763 -12.486 35.159
3 1 -45.588* 10.837 3234.292 .000 -71.544 -19.631
2 -11.337 9.946 3234.071 .763 -35.159 12.486
o 0 1 2 16.054 10.784 3234.192 .410 -9.775 41.884
3 32.632* 10.622 3234.191 .006 7.191 58.073
2 1 -16.054 10.784 3234.192 .410 -41.884 9.775
3 16.577 11.535 3233.999 .452 -11.051 44.205
3 1 -32.632* 10.622 3234.191 .006 -58.073 -7.191
2 -16.577 11.535 3233.999 .452 -44.205 11.051
1 1 2 16.149 10.791 3234.162 .404 -9.698 41.996
3 .061 10.604 3234.097 1.000 -25.338 25.460
2 1 -16.149 10.791 3234.162 .404 -41.996 9.698
3 -16.088 9.899 3234.136 .313 -39.798 7.622
3 1 -.061 10.604 3234.097 1.000 -25.460 25.338
2 16.088 9.899 3234.136 .313 -7.622 39.798
2 1 2 27.493* 10.078 3234.750 .019 3.353 51.633
409
3 18.964 9.727 3234.857 .154 -4.334 42.263
2 1 -27.493* 10.078 3234.750 .019 -51.633 -3.353
3 -8.528 9.742 3234.015 1.000 -31.862 14.805
3 1 -18.964 9.727 3234.857 .154 -42.263 4.334
2 8.528 9.742 3234.015 1.000 -14.805 31.862
u 0 1 2 59.298* 15.594 3234.186 .000 21.946 96.650
3 83.505* 16.101 3234.158 .000 44.939 122.071
2 1 -59.298* 15.594 3234.186 .000 -96.650 -21.946
3 24.207 11.744 3234.000 .118 -3.923 52.336
3 1 -83.505* 16.101 3234.158 .000 -122.071 -44.939
2 -24.207 11.744 3234.000 .118 -52.336 3.923
1 1 2 30.646 14.186 3234.149 .092 -3.332 64.625
3 51.969* 14.777 3234.093 .001 16.574 87.363
2 1 -30.646 14.186 3234.149 .092 -64.625 3.332
3 21.322 10.494 3234.099 .127 -3.814 46.459
3 1 -51.969* 14.777 3234.093 .001 -87.363 -16.574
2 -21.322 10.494 3234.099 .127 -46.459 3.814
2 1 2 4.377 13.770 3234.641 1.000 -28.605 37.360
3 20.452 14.498 3234.607 .475 -14.275 55.178
2 1 -4.377 13.770 3234.641 1.000 -37.360 28.605
3 16.074 10.235 3234.003 .349 -8.440 40.589
3 1 -20.452 14.498 3234.607 .475 -55.178 14.275
2 -16.074 10.235 3234.003 .349 -40.589 8.440
Based on estimated marginal means
a. Adjustment for multiple comparisons: Bonferroni.
*. The mean difference is significant at the .05 level.
b. Dependent Variable: F1.
410
3) Type III tests of fixed effects: Dependent variable F2.
Type III Tests of Fixed Effectsa
Source Numerator df Denominator df F Sig.
Intercept 1 8.013 34.166 .000
vowel 4 3234.136 19.511 .000
task 2 3234.503 5.957 .003
stress 1 3234.333 2.653 .103
syll 1 3234.200 2.305 .129
Gender 1 8.033 4.040 .079
Group 1 8.042 .419 .536
Travel 2 8.037 .153 .860
Grammar 1 8.042 .126 .732
ICCSTotal 1 8.016 1.709 .227
Spanuse 1 8.032 .325 .584
vowel * task 8 3234.201 23.463 .000
vowel * stress 4 3234.253 44.392 .000
vowel * syll 4 3234.148 6.472 .000
vowel * task * stress 10 3234.267 13.799 .000
vowel * task * syll 10 3234.166 4.676 .000
vowel * Gender 4 3234.160 75.305 .000
vowel * Group 4 3234.125 18.597 .000
vowel * Travel 8 3234.146 24.514 .000
vowel * Grammar 4 3234.073 23.917 .000
vowel * ICCSTotal 4 3234.134 .797 .527
vowel * Spanuse 4 3234.135 31.692 .000
vowel * task * Travel 20 3234.246 2.687 .000
a. Dependent Variable: F2.
411
4) Pairwise comparisons of interaction with dependent variable F2.
Pairwise Comparisonsb
vowel Travel (I) task
(J)
task
Mean
Difference
(I-J)
Std.
Error df Sig.a
95% Confidence
Interval for Differencea
Lower
Bound
Upper
Bound
a 0 1 2 22.769 24.252 3234.097 1.000 -35.321 80.859
3 44.422 29.467 3234.030 .395 -26.158 115.001
2 1 -22.769 24.252 3234.097 1.000 -80.859 35.321
3 21.653 30.684 3234.044 1.000 -51.841 95.147
3 1 -44.422 29.467 3234.030 .395 -115.001 26.158
2 -21.653 30.684 3234.044 1.000 -95.147 51.841
1 1 2 57.648* 22.610 3234.202 .032 3.493 111.804
3 114.107* 27.843 3234.157 .000 47.417 180.797
2 1 -57.648* 22.610 3234.202 .032 -111.804 -3.493
3 56.459 27.379 3234.091 .118 -9.119 122.037
3 1 -114.107* 27.843 3234.157 .000 -180.797 -47.417
2 -56.459 27.379 3234.091 .118 -122.037 9.119
2 1 2 -7.552 22.155 3234.097 1.000 -60.618 45.514
3 16.240 26.583 3234.160 1.000 -47.432 79.912
2 1 7.552 22.155 3234.097 1.000 -45.514 60.618
3 23.792 26.494 3234.079 1.000 -39.667 87.251
3 1 -16.240 26.583 3234.160 1.000 -79.912 47.432
2 -23.792 26.494 3234.079 1.000 -87.251 39.667
e 0 1 2 -37.384 25.939 3234.227 .449 -99.512 24.745
3 -248.313* 33.840 3234.100 .000 -329.367 -167.258
2 1 37.384 25.939 3234.227 .449 -24.745 99.512
3 -210.929* 34.232 3234.065 .000 -292.923 -128.935
3 1 248.313* 33.840 3234.100 .000 167.258 329.367
2 210.929* 34.232 3234.065 .000 128.935 292.923
1 1 2 .879 24.126 3234.602 1.000 -56.907 58.666
3 -180.006* 32.483 3234.382 .000 -257.809 -102.203
2 1 -.879 24.126 3234.602 1.000 -58.666 56.907
3 -180.885* 30.712 3234.051 .000 -254.448 -107.322
3 1 180.006* 32.483 3234.382 .000 102.203 257.809
2 180.885* 30.712 3234.051 .000 107.322 254.448
412
2 1 2 -43.789 24.232 3234.558 .213 -101.830 14.252
3 -292.299* 31.321 3234.387 .000 -367.320 -217.278
2 1 43.789 24.232 3234.558 .213 -14.252 101.830
3 -248.510* 30.200 3234.096 .000 -320.845 -176.175
3 1 292.299* 31.321 3234.387 .000 217.278 367.320
2 248.510* 30.200 3234.096 .000 176.175 320.845
i 0 1 2 33.323 34.778 3234.195 1.000 -49.978 116.625
3 -59.936 36.833 3234.095 .311 -148.159 28.287
2 1 -33.323 34.778 3234.195 1.000 -116.625 49.978
3 -93.260* 35.114 3234.057 .024 -177.366 -9.153
3 1 59.936 36.833 3234.095 .311 -28.287 148.159
2 93.260* 35.114 3234.057 .024 9.153 177.366
1 1 2 -67.100 32.829 3234.405 .123 -145.733 11.533
3 -129.950* 35.655 3234.425 .001 -215.351 -44.548
2 1 67.100 32.829 3234.405 .123 -11.533 145.733
3 -62.850 31.019 3234.186 .128 -137.148 11.448
3 1 129.950* 35.655 3234.425 .001 44.548 215.351
2 62.850 31.019 3234.186 .128 -11.448 137.148
2 1 2 -140.302* 30.774 3234.176 .000 -214.012 -66.593
3 -194.999* 33.194 3234.421 .000 -274.507 -115.491
2 1 140.302* 30.774 3234.176 .000 66.593 214.012
3 -54.697 30.466 3234.123 .218 -127.670 18.275
3 1 194.999* 33.194 3234.421 .000 115.491 274.507
2 54.697 30.466 3234.123 .218 -18.275 127.670
o 0 1 2 1.706 33.032 3234.287 1.000 -77.414 80.825
3 62.749 32.535 3234.286 .162 -15.181 140.679
2 1 -1.706 33.032 3234.287 1.000 -80.825 77.414
3 61.044 35.332 3234.025 .252 -23.585 145.672
3 1 -62.749 32.535 3234.286 .162 -140.679 15.181
2 -61.044 35.332 3234.025 .252 -145.672 23.585
1 1 2 46.773 33.054 3234.247 .471 -32.400 125.945
3 112.515* 32.482 3234.159 .002 34.714 190.315
2 1 -46.773 33.054 3234.247 .471 -125.945 32.400
3 65.742 30.321 3234.211 .091 -6.884 138.368
3 1 -112.515* 32.482 3234.159 .002 -190.315 -34.714
2 -65.742 30.321 3234.211 .091 -138.368 6.884
2 1 2 48.879 30.871 3235.037 .340 -25.064 122.822
3 82.877* 29.794 3235.180 .016 11.512 154.241
413
2 1 -48.879 30.871 3235.037 .340 -122.822 25.064
3 33.997 29.841 3234.047 .764 -37.478 105.473
3 1 -82.877* 29.794 3235.180 .016 -154.241 -11.512
2 -33.997 29.841 3234.047 .764 -105.473 37.478
u 0 1 2 -97.048 47.767 3234.279 .127 -211.462 17.366
3 -7.258 49.320 3234.241 1.000 -125.390 110.874
2 1 97.048 47.767 3234.279 .127 -17.366 211.462
3 89.790* 35.974 3234.026 .038 3.625 175.955
3 1 7.258 49.320 3234.241 1.000 -110.874 125.390
2 -89.790* 35.974 3234.026 .038 -175.955 -3.625
1 1 2 66.856 43.454 3234.229 .372 -37.225 170.937
3 156.335* 45.265 3234.153 .002 47.917 264.754
2 1 -66.856 43.454 3234.229 .372 -170.937 37.225
3 89.479* 32.145 3234.161 .016 12.484 166.475
3 1 -156.335* 45.265 3234.153 .002 -264.754 -47.917
2 -89.479* 32.145 3234.161 .016 -166.475 -12.484
2 1 2 -101.008 42.179 3234.893 .050 -202.037 .021
3 -29.834 44.409 3234.847 1.000 -136.204 76.536
2 1 101.008 42.179 3234.893 .050 -.021 202.037
3 71.174 31.351 3234.030 .070 -3.918 146.267
3 1 29.834 44.409 3234.847 1.000 -76.536 136.204
2 -71.174 31.351 3234.030 .070 -146.267 3.918
Based on estimated marginal means
a. Adjustment for multiple comparisons: Bonferroni.
*. The mean difference is significant at the .05 level.
b. Dependent Variable: F2.
414
5) Type III tests of fixed effects: Dependent variable Euclidean distance.
Type III Tests of Fixed Effectsa
Source Numerator df Denominator df F Sig.
Intercept 1 7.975 2.219 .175
vowel 4 3234.148 5.397 .000
task 2 3234.660 88.682 .000
stress 1 3234.424 183.485 .000
syll 1 3234.237 39.221 .000
Gender 1 8.003 14.819 .005
Group 1 8.016 1.861 .210
Travel 2 8.009 2.939 .110
Grammar 1 8.015 3.051 .119
ICCSTotal 1 7.980 .024 .881
Spanuse 1 8.001 4.170 .075
vowel * task 8 3234.239 5.937 .000
vowel * stress 4 3234.312 23.173 .000
vowel * syll 4 3234.165 1.032 .389
vowel * task * stress 10 3234.332 14.561 .000
vowel * task * syll 10 3234.190 4.483 .000
vowel * Gender 4 3234.182 20.072 .000
vowel * Group 4 3234.132 9.170 .000
vowel * Travel 8 3234.162 10.768 .000
vowel * Grammar 4 3234.059 4.525 .001
vowel * ICCSTotal 4 3234.145 4.946 .001
vowel * Spanuse 4 3234.146 17.503 .000
vowel * task * Travel 20 3234.302 3.003 .000
a. Dependent Variable: EUC.
415
6) Pairwise comparisons of interaction with dependent variable Euclidean Distance.
Pairwise Comparisonsb
vowel Travel (I) task
(J)
task
Mean
Difference
(I-J)
Std.
Error df Sig.a
95% Confidence
Interval for Differencea
Lower
Bound
Upper
Bound
a 0 1 2 -11.813 19.579 3234.093 1.000 -58.709 35.083
3 -45.966 23.789 3233.998 .160 -102.945 11.013
2 1 11.813 19.579 3234.093 1.000 -35.083 58.709
3 -34.153 24.771 3234.018 .504 -93.485 25.178
3 1 45.966 23.789 3233.998 .160 -11.013 102.945
2 34.153 24.771 3234.018 .504 -25.178 93.485
1 1 2 -31.757 18.253 3234.241 .246 -75.477 11.962
3 -95.287* 22.478 3234.177 .000 -149.126 -41.449
2 1 31.757 18.253 3234.241 .246 -11.962 75.477
3 -63.530* 22.103 3234.084 .012 -116.472 -10.589
3 1 95.287* 22.478 3234.177 .000 41.449 149.126
2 63.530* 22.103 3234.084 .012 10.589 116.472
2 1 2 -24.618 17.886 3234.094 .506 -67.458 18.222
3 -76.145* 21.460 3234.182 .001 -127.548 -24.743
2 1 24.618 17.886 3234.094 .506 -18.222 67.458
3 -51.528* 21.389 3234.068 .048 -102.758 -.297
3 1 76.145* 21.460 3234.182 .001 24.743 127.548
2 51.528* 21.389 3234.068 .048 .297 102.758
e 0 1 2 -9.245 20.940 3234.275 1.000 -59.401 40.912
3 -191.701* 27.319 3234.097 .000 -257.136 -126.266
2 1 9.245 20.940 3234.275 1.000 -40.912 59.401
3 -182.456* 27.636 3234.049 .000 -248.650 -116.263
3 1 191.701* 27.319 3234.097 .000 126.266 257.136
2 182.456* 27.636 3234.049 .000 116.263 248.650
1 1 2 9.711 19.476 3234.799 1.000 -36.939 56.361
3 -128.512* 26.223 3234.493 .000 -191.322 -65.702
2 1 -9.711 19.476 3234.799 1.000 -56.361 36.939
3 -138.223* 24.794 3234.028 .000 -197.610 -78.836
3 1 128.512* 26.223 3234.493 .000 65.702 191.322
416
2 138.223* 24.794 3234.028 .000 78.836 197.610
2 1 2 -6.973 19.562 3234.736 1.000 -53.829 39.882
3 -233.361* 25.285 3234.499 .000 -293.925 -172.797
2 1 6.973 19.562 3234.736 1.000 -39.882 53.829
3 -226.388* 24.380 3234.092 .000 -284.784 -167.992
3 1 233.361* 25.285 3234.499 .000 172.797 293.925
2 226.388* 24.380 3234.092 .000 167.992 284.784
i 0 1 2 37.507 28.076 3234.230 .545 -29.742 104.756
3 -59.117 29.735 3234.091 .141 -130.340 12.105
2 1 -37.507 28.076 3234.230 .545 -104.756 29.742
3 -96.624* 28.348 3234.037 .002 -164.523 -28.725
3 1 59.117 29.735 3234.091 .141 -12.105 130.340
2 96.624* 28.348 3234.037 .002 28.725 164.523
1 1 2 -80.764* 26.503 3234.524 .007 -144.244 -17.284
3 -158.243* 28.784 3234.552 .000 -227.187 -89.299
2 1 80.764* 26.503 3234.524 .007 17.284 144.244
3 -77.479* 25.042 3234.218 .006 -137.459 -17.498
3 1 158.243* 28.784 3234.552 .000 89.299 227.187
2 77.479* 25.042 3234.218 .006 17.498 137.459
2 1 2 -117.622* 24.843 3234.205 .000 -177.127 -58.116
3 -172.507* 26.798 3234.547 .000 -236.693 -108.321
2 1 117.622* 24.843 3234.205 .000 58.116 177.127
3 -54.885 24.595 3234.130 .077 -113.796 4.025
3 1 172.507* 26.798 3234.547 .000 108.321 236.693
2 54.885 24.595 3234.130 .077 -4.025 113.796
o 0 1 2 4.750 26.667 3234.360 1.000 -59.123 68.623
3 -50.574 26.266 3234.359 .163 -113.486 12.338
2 1 -4.750 26.667 3234.360 1.000 -68.623 59.123
3 -55.324 28.524 3233.992 .158 -123.644 12.997
3 1 50.574 26.266 3234.359 .163 -12.338 113.486
2 55.324 28.524 3233.992 .158 -12.997 123.644
1 1 2 -27.803 26.685 3234.303 .893 -91.718 36.113
3 -114.627* 26.222 3234.180 .000 -177.435 -51.818
2 1 27.803 26.685 3234.303 .893 -36.113 91.718
3 -86.824* 24.478 3234.254 .001 -145.454 -28.193
3 1 114.627* 26.222 3234.180 .000 51.818 177.435
2 86.824* 24.478 3234.254 .001 28.193 145.454
2 1 2 -59.586 24.921 3235.399 .051 -119.278 .107
417
3 -89.880* 24.052 3235.593 .001 -147.490 -32.269
2 1 59.586 24.921 3235.399 .051 -.107 119.278
3 -30.294 24.091 3234.023 .626 -87.997 27.408
3 1 89.880* 24.052 3235.593 .001 32.269 147.490
2 30.294 24.091 3234.023 .626 -27.408 87.997
u 0 1 2 74.528 38.562 3234.349 .160 -17.837 166.894
3 -1.932 39.816 3234.295 1.000 -97.299 93.436
2 1 -74.528 38.562 3234.349 .160 -166.894 17.837
3 -76.460* 29.042 3233.994 .026 -146.022 -6.899
3 1 1.932 39.816 3234.295 1.000 -93.436 97.299
2 76.460* 29.042 3233.994 .026 6.899 146.022
1 1 2 -62.956 35.080 3234.279 .218 -146.980 21.069
3 -144.475* 36.542 3234.172 .000 -232.002 -56.949
2 1 62.956 35.080 3234.279 .218 -21.069 146.980
3 -81.520* 25.951 3234.183 .005 -143.678 -19.361
3 1 144.475* 36.542 3234.172 .000 56.949 232.002
2 81.520* 25.951 3234.183 .005 19.361 143.678
2 1 2 71.384 34.051 3235.202 .108 -10.175 152.943
3 4.539 35.851 3235.138 1.000 -81.331 90.410
2 1 -71.384 34.051 3235.202 .108 -152.943 10.175
3 -66.845* 25.310 3234.000 .025 -127.467 -6.222
3 1 -4.539 35.851 3235.138 1.000 -90.410 81.331
2 66.845* 25.310 3234.000 .025 6.222 127.467
Based on estimated marginal means
a. Adjustment for multiple comparisons: Bonferroni.
*. The mean difference is significant at the .05 level.
b. Dependent Variable: EUC.
Rebecca Ellen Ronquest
EDUCATION 2012 Ph.D. Hispanic Linguistics, Indiana University Minor: General Linguistics Dissertation: An Acoustic Analysis of Heritage Spanish Vowels. Director: Dr. Erik W. Willis Committee: Dr. Kimberly Geeslin, Dr. Manuel Díaz-Campos, Dr. Kenneth de Jong 2004 M.A. Hispanic Linguistics, Indiana University M.A. Linguistics, Indiana University 2002 B.A. Spanish, The College of William & Mary
Summa Cum Laude
RESEARCH INTERESTS Acoustic phonetics, Sociolinguistics, Bilingualism, Heritage Spanish, Speech Perception
PROFESSIONAL EMPLOYMENT 2002-2011 Associate Instructor of Spanish, Indiana University 2005-2006 Research Assistant. National Institutes of Health (NIH) Pre- Summer 2007 doctoral Fellow, Indiana University Speech Research Lab. Summer 2008 Dr. David Pisoni, Director. 2001 Spanish Drill Instructor, The College of William & Mary
PUBLICATIONS Refereed Journals 2012 Ronquest, R. (Accepted). An acoustic examination of unstressed
vowel reduction in Heritage Spanish. Selected proceedings from the 2011 Hispanic Linguistics Symposium (HLS).
2010 Ronquest, R., Levi, S., & Pisoni, B. (2010). Language
identification from visual-only speech signals. Attention, Perception, and Psychophysics, 72(6), 1601-1613.
2009 Ronquest, R., & Díaz-Campos, M. (2009). Discriminating pitch-accent alignment in Spanish. In Masullo, P., O'Rourke, E., & Huang, C. (Eds.), Romance Linguistics 2007: Selected papers from the 37th Linguistic Symposium on Romance Languages (LSRL), (pp. 243-260). Philadelphia: Benjamins.
2007 Díaz-Campos, M., & Ronquest, R. (2007). La percepción de
acentos tonales en enunciados afirmativos. Estudios de fonética experimental, 16, 81-98.
Progress Reports 2007 Ronquest, R., Levi, S., & Pisoni, B. (2007). Language
identification from visual-only speech. In Research on Spoken Language Processing Progress Report No. 28, 95-118.
2006 Ronquest, R., & Hernandez, L. (2006). Lip-reading skills in
bilinguals. In Research on Spoken Language Processing Progress Report No. 27, 219-226.
PRESENTATIONS Conference Presentations 2012 Ronquest, R. (2012, March). An acoustic analysis of the effects of
syllable type on Heritage Spanish vowel production. Paper presented at The Ninth Annual Graduate Student Conference on Luso-Brazilian and Hispanic Linguistics, Literature and Culture, Bloomington, IN.
2012 Ronquest, R. (2012, February). The effect of speech style on the
acoustic distribution of Heritage Spanish vowels. Poster presented at Current Approaches to Spanish and Portuguese Second Language Phonology 2012, Colombia, SC.
2011 Ronquest, R. (2011, October). An analysis of mid-vowel
variation in Heritage Spanish. Poster presented at The 17th Annual Mid-Continental Workshop on Phonetics and Phonology, Urbana, IL.
2011 Ronquest, R. (2011, October). An acoustic characterization of
the Heritage Spanish vowel system. Paper presented at The 2011 Hispanic Linguistics Symposium, Athens, GA.
2008 Ronquest, R., Levi, S., & Pisoni, D. (2008, July). Visual cues to language identification. Paper presented at The Linguistic Society of America Summer Meeting, Columbus, OH.
2007 Ronquest, R., & Díaz-Campos, M. (2007,April). Discriminating
pitch-accent alignment in Spanish: A pilot investigation. Paper presented at The Kentucky Foreign Language Conference, Lexington, KY.
2007 Ronquest, R., & Díaz-Campos, M. (2007, March). A perceptual
discrimination study of pitch-accent alignment in Spanish. Paper presented at The Linguistic Symposium on Romance Languages XXXVII, Pittsburgh, PA.
Lab Talks and Invited Presentations 2011 Ronquest, R. (2011, November). Living in two languages: A
linguistic study of bilingual youths. Paper presented at the Latino Studies Program Brown Bag series. Indiana University, Bloomington, IN.
2010 Ronquest, R. (2010, December). An acoustic analysis of
Heritage Spanish vowels. Paper presented at the Hispanic Linguistics Brown Bag series. Department of Spanish and Portuguese, Indiana University, Bloomington, IN.
2008 Ronquest, R. (2008, February). Language identification from
visual-only speech signals. Paper presented at the Hispanic Linguistics Brown Bag series, Department of Spanish and Portuguese, Indiana University, Bloomington, IN.
2007 Ronquest, R. (2007, February). Examining pitch-accent
alignment in Spanish. Paper presented at the Hispanic Linguistics Brown Bag series. Department of Spanish and Portuguese, Indiana University, Bloomington, IN.
2006 Ronquest, R. (2006, December). Visual-only language
identification in monolinguals and bilinguals. Paper presented at lab meeting, Speech Research Laboratory, Indiana University, Bloomington, IN.
TEACHING EXPERIENCE Courses Taught 2002-2011 Associate Instructor, Indiana University
S326--Introduction to Hispanic Linguistics (Fall 2008, Spring 2010, Fall 2010, Spring 2011) S280--Spanish Grammar in Context (Fall 2009) S275--Introduction to Spanish History and Culture (Spring 2008, Fall 2008) S250--Intermediate Spanish II (Fall 2007) S200--Intermediate Spanish I (Fall 2003, Spring 2004) S105--Accelerated first year Spanish (Fall 2002, Spring 2003, Fall 2004, Spring 2007)
2001 Drill instructor, The College of William & Mary HISP 101 Drill--Beginning level Spanish (Fall 2001) Tutoring 2005-Present Tutored students enrolled in university-level Spanish courses at
Indiana University. Ability levels ranged from beginning to advanced.
2001-2002 Tutor employed by University Instructors, Inc, in Williamsburg,
Virginia. Tutored high school students enrolled in beginning-level Spanish and Advanced Placement Spanish.
SERVICE AND VOLUNTEER ACTIVITIES Teaching 2009 Participant in Language Teaching Share Fair. Presented original
warm-up activity entitled “A improvisar” to other graduate teaching instructors during a workshop on designing effective warm-up activities for foreign language teaching.
2001-2002 Volunteer Spanish teacher at Matthew Whaley Elementary School
in Williamsburg, Virginia. Taught Spanish to first graders one to two times per week during the Spring semesters of 2001 and 2002.
Professional 2011 Reviewer, Selected Proceedings from the Hispanic Linguistics Symposium. 2010 Chair of session on Heritage Speakers, and provided opening
remarks for keynote address at the Hispanic Linguistics Symposium at Indiana University.
2009 Reviewer, Indiana University Working Papers Online. 2001 Volunteer translator for Eastern Shore Rural Health, Inc., as part
of a service-learning program at The College of William & Mary. Performed medical translation for migrant workers who visited the rural health clinics, and also went to migrant camps to give short, educational presentations on basic health practices.
AWARDS AND HONORS 2012 Outstanding graduate student poster award at Current Approaches
to Spanish and Portuguese Second Language Phonology (conference)
2011-2012 Latino Studies Program Dissertation Year Fellowship 2009-2010 Distinguished Teaching Award at Indiana University 2002-2003 Distinguished Teaching Award at Indiana University 2002 R.Merrit Cox Memorial Fellowship at The College of William &
Mary for exceptional undergraduate student pursuing graduate study.
2002 Phi Beta Kappa Society, Alpha Chapter, The College of William & Mary
2002 Golden Key National Honor Society at The College of William & Mary
LANGUAGES Spanish Near-native fluency Italian Intermediate-level speaking, reading, and comprehension German Beginning-level speaking, reading, and comprehension Latin Reading knowledge
