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Acoustic correlates of prominence in Tashlhiyt Berber

Matthew Gordon & Latifa Nafi University of California, Santa Barbara

Abstract This paper reports results of a phonetic study of prominence in Tashlhiyt Berber, an Afro-Asiatic language that is famous for possessing words consisting of only obstruents. This study examines evidence for word-level stress and phrase-level accent in Tashlhiyt and addresses the question of how prominence is acoustically realized in segments, such as obstruents, that provide a relatively impoverished backdrop for the manifestation of prominence. Results indicate that F0 is raised in the phrase-final syllable relative to both the penultimate syllable of the phrase and also to word-final syllables that are phrase-medial. This raising of F0 is consistently observed on sonorant nuclei, inconsistently associated with voiced obstruents, and absent from voiceless obstruents, which lack an F0 but often trigger insertion of an epenthetic vowel to aid in the realization of F0 information. A further result is that intensity is higher in the nucleus of a word-final syllable relative to one in the penult of a word. We interpret the greater intensity associated with word-final syllables as a marker of word-level stress and the raising of F0 in phrase-final syllables as a phrase-level pitch accent docking on the final stressed syllable of a phrase. Keywords: Tashlhiyt, stress, pitch accent, prominence, epenthesis

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1. Introduction

The examination of prominence has been a productive area of both phonological and phonetic

research for several decades. Since the pioneering work by Fry (1955, 1958) on the acoustic

correlates of stress in English, our cross-linguistic understanding of the relationship between the

phonological structures underlying prominence and their phonetic manifestation has increased

substantially through detailed prosodic studies of an ever broadening number of languages. It has

become apparent that prominence operates at multiple prosodic levels both phonologically and

phonetically. Individual words may be associated with stress on one or more syllables, while

phrases also contribute an additional layer of prominence by promoting one or more lexical

stresses to pitch accents (see Ladd 1996 and Gussenhoven 2004 for an overview). These pitch

accents are salient intonational events, such as peaks, troughs or transitions, that have a

phonological status and are characteristically analyzed as discrete high and low tonal targets, i.e.

H*, L*, or combinations of targets, e.g. H* + L, L* + H, docking on certain lexically stressed

syllables. For example, under a semantically neutral pronunciation of the English phrase Mary

saw an álligator, the first syllable in álligator characteristically carries a H* pitch accent by

virtue of its being the primary stressed syllable in the rightmost content word. The domain of

pitch accents is characteristically assumed to be a major intonational constituent, termed the

“Intonational Phrase” in an autosegmental framework (Pierrehumbert 1980). Besides being

associated with one or pitch accents, the Intonational Phrase (IP) is also defined by a terminal F0

boundary tone. For example, when uttered as a statement, the end of the IP Mary saw an

alligator is associated with a L% boundary tone, which yields an F0 fall.

There are many interesting areas of research involving the study of word-level stress and

phrase-level accent. One of these concerns the relationship between the phonological status of

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stress and accent and the phonetic realization of both. In principle, the distinguishing acoustic

feature associated with a pitch accent is an F0 peak, trough, or transition, whereas stress may be

realized with several acoustic properties, including raised fundamental frequency, increased

intensity, either across the entire frequency range or skewed toward higher frequencies, greater

duration, and changes in vowel quality, e.g. English (Fry 1955, 1958, Beckman 1986), Kabardian

(Gordon & Applebaum 2010), Polish (Jassem et al. 1968), Mari (Baitschura 1976), Indonesian

(Adisasmito-Smith & Cohn 1996), Tagalog (Gonzalez 1970), Dutch (Sluijter & van Heuven

1996a), Pirahã (Everett 1998), Chickasaw (Gordon 2004), Turkish (Levi 2005). There is also the

possibility that stress is a more abstract entity that only has an overt physical realization in

certain contexts, namely those associated with intonational pitch accents. Under this

interpretation, a stressed syllable is one that has the potential to but need not carry a pitch accent.

Another important issue in the study of pitch accents concerns tune-text alignment, the

phonological association of pitch accents with syllables and segments within syllables. Parallel

to tones in tone languages, pitch accents dock on syllables or, in some languages, on certain

moras within a syllable. An example of mora-governed pitch accent placement is provided by

Chickasaw questions (Gordon 2008), in which the pitch accent falls on the penultimate mora,

where long vowels are linked to two moras, short vowels to one, and consonants are non-moraic.

Because the moraic status of different segments is determined on a language-specific basis,

languages with mora-governed pitch accent placement may vary in terms of which segments are

eligible to receive a pitch accent just as tones vary in their permissible docking sites in tone

languages (Zhang 2002).

Both the interface between stress and accent and the tonal alignment of pitch accents are

linked by an important issue related to the capacity of different types of sounds to realize

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acoustic properties associated with prominence. In virtually all languages of the world, every

syllable contains a vowel or at least a sonorant consonant that, like a vowel, is characterized by

periodic acoustic energy. In languages fitting this profile, both stress and pitch accents have

available phonological docking sites that allow for their salient phonetic production. Sonorant

sounds, including vowels and sonorant consonants, are characterized by a rich harmonic

structure well-suited to realizing any of the properties traditionally associated with stress (e.g.

increased duration, intensity, and/or higher F0) or pitch accent (a salient F0 event). Obstruents,

on the other hand, are severely hindered in their ability to cue stress or accent. Although

increased duration and intensity are still potentially available as cues to stress on an obstruent,

fundamental frequency cues associated with either stress or pitch accent are less salient when

associated with an obstruent and are completely unavailable if this obstruent is voiceless. Given

the phonetic difficulties associated with producing a pitch accent on an obstruent, one might

hypothesize that a language would phonologically restrict pitch accents to sonorants, much as

virtually all tone languages limit the association of tones to sonorants (Zhang 2002).

Furthermore, because obstruents are less intense than sonorants and because listeners are

perceptually less attuned to differences in duration associated with obstruents (Goedemans

1998), the usefulness of intensity and duration as cues to stress is likely diminished when

associated with an obstruent relative to a sonorant.

This paper examines stress and pitch accent in Tashlhiyt Berber, a language that is well

known in the phonetic and phonological literature (e.g. Dell & Elmedlaoui 1985, 1988, 2002,

Coleman 1996, 1999, 2001, Ridouane 2008a, Fougeron & Ridouane 2008a, etc.) for having

words without vowels and even words without any sonorants at all. We focus on several

questions. First, we examine the phonetic evidence for word-level stress and phrase-level pitch

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accent in words containing sonorant sounds, thereby adding to the extremely sparse literature on

Tashlhiyt prosody. We adopt the working hypothesis that Tashlhiyt possesses at least phrase-

level and possibly also word-level prominence, realized through some combination of raised F0

and/or increased duration and/or intensity. Second, we investigate how stress and pitch accent

are realized on syllables consisting of only obstruents, which are inherently less prominent than

sonorants. We hypothesize that the realization of prominence associated with obstruent nuclei

relies more on duration and intensity than F0, since the manipulation of duration and intensity as

cues to prominence are more compatible with obstruents than the manipulation of F0. Third, we

explore the alignment of pitch accents in words containing syllabic obstruents, which are

particularly ill-suited to conveying tonal information. Finally, we explore one potential strategy

for realizing prominence in obstruent-only words, vowel epenthesis, which has previously been

described in the literature on Tashlhiyt (Dell & Elmedlaoui 2002) as a phonotactically-driven

rather than a prominence-driven phenomenon.

2. Background Tashlhiyt is a Northern Berber (Afro-Asiatic) language spoken in the Atlas mountain region of

Morocco. Tashlhiyt phonology and morphology has been relatively well-documented largely

through the impressively comprehensive publications of François Dell and his colleague,

Mohamed Elmedlaoui, a native speaker of Imdlawn Tashlhiyt (e.g Dell & Elmedlaoui 1985,

1988, 1989, 1991, 1992, 2002, 2008). More recently, Rachid Ridouane has authored and co-

authored several papers illuminating interesting features of the Tashlhiyt Berber phonetic system

(e.g. Ridouane 2007, 2008a, 2008b, 2010, Fougeron & Ridouane 2008a,b).

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The bulk of the phonetic and phonological literature on Tashlhiyt has focused on its

typologically unusual prosodic structure, which permits syllables and even words consisting

entirely of obstruent consonants, e.g. tqs.sf ‘it shrunk’, sfq.qst ‘irritate him’, ts.sk.Sf.tstt ‘you

dried it (fem.)’ (Ridouane 2008:332). (Note that transcriptions of Tashlhiyt used in this paper are

phonemic unless stated otherwise.) As the aforementioned literature points out, the existence of

words consisting of only obstruents presents challenges to the theory of syllables. For example, it

is a priori unclear how obstruent-only words are syllabified by Tashlhiyt speakers or, indeed,

whether syllables are a relevant construct for speakers. In their seminal research on Tashlhiyt

syllabification, Dell and Elmedlaoui (1985, 1988), in fact, show that syllables are

psychologically real entities that play a crucial organizational role in the language, both in the

phonology and morphology as well as in versification. They present a detailed algorithm for

syllabification that accounts both for words containing vowels and sonorant consonants as well

as for words consisting only of obstruents. According to the Dell and Elmedlaoui (1985)

analysis, syllabification is sensitive to the sonority hierarchy in Figure 1, where higher sonority

sounds are preferentially selected as syllable nuclei over lower sonority sounds.

More sonorous Less sonorous Low V High V Liquid Nasal Vcd fricative Vcl fricative Vcd stop Vcl stop

Figure 1. Tashlhiyt sonority hierarchy

The construction of core syllables consisting of an onset and a nucleus proceeds from left to right

selecting the highest remaining unparsed sound as a nucleus and the immediately preceding

sound as an onset for that nucleus. Onsetless syllables are allowed only at the beginning of

postpausal words. Any segments not parsed as nuclei or onsets are annexed as codas by the

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preceding syllable. For example, in the parse of the word /ħaUltn/ (Dell and Elmedlaoui

1985:110) (where U stands for an underlying not yet syllabified high front vocoid), the sequence

/ħa/ is first grouped into a syllable with /a/ as the nucleus since /a/ is the most sonorous sound in

the sonority hierarchy. The scan continues to the right of /a/ selecting as a nucleus the next most

sonorous sound that is preceded by a sound that can function as an onset. Because the prohibition

against word-internal onsetless syllables precludes syllabifying /U/ as a nucleus, /l/ is parsed as

the second nucleus with /U/ as its onset. Finally, the string /tn/ is parsed as a syllable with /n/, the

next most sonorous sound in the hierarchy, functioning as the nucleus, yielding the final parse

ħa.wl.tn. For the word /tftkt/ ‘you suffered a sprain’ (Dell and Elmedlaoui 1985:113), the most

sonorous segment is /f/ which is parsed as a nucleus with the preceding /t/ serving as its onset.

The parse continues to the right of /t/ choosing /k/ as the next nucleus over the preceding /t/ since

/t/ is not preceded by an unparsed segment that could function as its onset. The /t/ preceding /k/

thus serves as the onset to the syllable headed by /k/. The only available option for the word-final

/t/ is to be parsed as a coda to the preceding syllable. The final parse is thus tf.tkt.

In contrast to syllabification, one prosodic area that has received very little attention in the

literature on Tashlhiyt is stress and, more generally, prominence. Dell and Elmedlaoui (2002:14)

suggest that any phenomenon of stress or accent is likely a feature of prosodic units larger than

the word. The hypothesis that word-level stress is not a salient feature of Tashlhiyt is consonant

with our experience working with native speakers, who are not able to consistently pinpoint a

syllable as being stressed either through direct inquiry or through tapping-type experiments in

which speakers are asked to tap their finger during the production of prominent syllables.

Dell and Elmedlaoui propose that the main intonational event in a phrase occurs near its end

on the final or penultimate syllable containing a sonorant nucleus. In the context of their work on

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syllabification, Dell and Elmedlaoui (1985:119) discuss one of these intonational events in

questions expressing puzzlement, which end in a sequence of low pitch followed by a pitch rise.

Their discussion of this contour, which docks on the final tone-bearing unit of a phrase, raises

one of the interesting issues guiding the present work on stress. They formulate a rule of

‘prepausal annexation’ that forces open syllables that would otherwise (i.e. in non-phrase final

position or in final position of phrases associated with other intonation contours) have a voiceless

nucleus to attach to the preceding syllable as a coda cluster and pass the pitch rise leftward to the

immediately preceding voiced nucleus. For example, irks ‘he hid’, which is characteristically

syllabified as ir.ks is instead realized prepausally under the puzzled question tune as

monosyllabic irks with the final pitch contour realized on the /i/ rather than the /s/ that would be

the final nucleus of the word in other contexts.

The phonetic motivation for the shifting of the terminal pitch contour to the preceding vowel

in words like irks is clear: a voiceless nucleus like /s/ is ill-suited to supporting intonational

contours since it has no fundamental frequency. Similar issues potentially arise more broadly in

all positions where prominence or prosodic boundaries are potentially relevant, including all

phrase-final contexts not just in phrases associated with the puzzled question tune, as well as

focused elements, and even word-level stress, to the extent that it occurs in Tashlhiyt. The

present paper aims to examine how prominence is phonetically realized in Tashlhiyt, focusing on

two types of prominence, phrase-level pitch accent, which the literature suggests is salient in

Tashlhiyt, and word-level stress, whose characterization is potentially more illusory.

3. Methodology

For the present study, a corpus of disyllabic words containing various types of syllable

nuclei in both final and penultimate syllables was constructed by the second author, a native

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speaker of Tashlhiyt. Dell and Elmedlaoui’s (1985) syllabification algorithm was assumed,

which, in short, preferentially constructs syllables containing more sonorant nuclei only moving

on to less sonorant nuclei after options for creating syllables with more sonorant nuclei have

been exhausted (see section 2). Syllable nuclei in the present work were varied between vowels,

sonorant consonants, and voiced and voiceless obstruents. In a subset of words, e.g. sslslt

‘necklace’, both the penult and the final syllable contained the same nucleus, thereby allowing

for the comparison of both nuclei in the same word. In other words, either the final or the

penultimate nucleus was targeted for measurement and compared with the same sound occurring

in the other position in a different word. For example, the sound /s/ was compared in the penult

of tr.ks.tn ‘She hides them (masc.)’ and in the final syllable of tr.kst ‘She hides it (masc.)’.

Three measurements were made for each target nucleus using Praat (Boersma and Weenink

2010): duration, average fundamental frequency and average intensity. Duration was measured

from a waveform with the assistance of a time-aligned spectrogram. Average fundamental

frequency and average intensity were both calculated for the entire nucleus. Throughout the

measurement process, any transitional vocoids (see Dell and Elmedlauoui 2002 for discussion of

transitional vowels in Tashlhiyt) appearing in either of the final two syllables of a word were

tracked. The duration, average fundamental frequency and average intensity of the transitional

vowels were measured following the same procedure adopted for the syllable nuclei.

All words were either two or three syllables in order to minimize the potential confounding

effect of number of syllables on the length of the target segments. In order to reduce

microprosodic effects on duration, intensity, and F0, the sounds adjacent to target segments

differing in their location (e.g. /x/ in the penult in tf.tx.tn ‘She rolled them (masc.)’ vs. /x/ in the

ultima in tf.txt ‘She rolled it (masc.)’) were either identical or shared the same voicing features,

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as voicing characteristically exerts a greater effect than place of articulation on the measured

parameters (Lehiste 1970).

Target words were elicited in two contexts: in isolation, where the word is equivalent to a

phrase (the phrase-final context), and followed by the word ʁilad ‘now’, where the target word is

shielded from the right edge of the phrase (the phrase-medial context). The stimuli were not

presented in any context that would trigger special emphasis, e.g. contrastive focus, on the target

word other than that normally associated with the position in which the word appears. The list of

targeted words comprised 21 items (see the appendix for corpus), which were presented to the

subject to read in randomized order five times in isolation and then five times in the phrasal

context. Data were recorded by the second author onto a Marantz PMD660 solid-state recorder

in .wav format at a sampling rate of 44.1kHz via a high quality unidirectional head mounted

microphone (Shure SM10). Six subjects (three female and three male), all of whom were native

speakers of Tashlhiyt Berber born in Morocco and currently residing in the United States,

provided the recordings serving as the basis for this paper.

After analysis, data were subjected to statistical analysis. For the study of acoustic correlates

of prominence, repeated measures ANOVAs (analyses of variance) pooled over all speakers, or,

in the case of F0, over all speakers of the same gender, were performed for the three measured

parameters with syllable position (the final syllable of a phrase-final word vs. the penultimate

syllable of a phrase-final word vs. the final syllable of a phrase-medial word vs. the penultimate

syllable of a phrase-medial word) serving as the within subjects variable. Greenhouse-Geisser

corrections were employed in cases where sphericity was violated. Bonferroni posthoc tests

(corrected for multiple comparisons) were also performed to compare the different conditions for

a given variable. Individual speaker ANOVAs were then conducted to assess interspeaker

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variation. In the study of prominence in epenthetic vowels, t-tests were employed due to gaps in

the data resulting from the cross-classification of syllable and phrasal position.

4. Results

Impressionistic evaluation of the data suggests that the most salient prosodic characteristic is

higher F0 in the final syllable of words uttered in isolation. The terminal F0 rise was consistent

throughout words of different shapes, both in the data that were quantitatively analyzed and in

additional words elicited, even if the final syllable nucleus was preceded by a more sonorous

nucleus in an earlier syllable. For example, in the word. ib.bZ.tn ‘He crushes them (masc.)’, the

final sonorant consonant is associated with higher F0 than not only the voiced fricative in the

penultimate syllable but also the vowel in the initial syllable. Similarly, in tu.fi.tnt ‘You (fem.)

found them (fem)’, the /n/ in the final syllable has higher F0 than either of the first two vowels.

Nor does syllable weight seem to impact the location of the F0 peak on the final syllable, since

light final syllables routinely are associated with an F0 peak, e.g. i.fas.sn ‘hands’, tr.gl.tn ‘She

locks them (masc.)’

The raised F0 on the final syllable of the phrase is evident in figures 2 and 3, which show

waveforms and pitch traces for representative tokens of tsikit ‘She missed it’ uttered in isolation

by two different female speakers. Figure 4 contains a representative exemplar of the phrase tsikit

ʁilad ‘She missed it now’ produced by the same speaker pronouncing the isolated word tsikit

shown in figure 2.

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Time (s)

0 0.7608250

420 t s i k i t

Figure 2. A representative waveform and pitch trace for the word tsikit ‘She missed it’ uttered in isolation by a female speaker.

Time (s)

0 0.6997185

220 t s i k i t

Figure 3. A representative waveform and pitch trace for the word tsikit ‘She missed it’ uttered in isolation by a female speaker.

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Time (s)

0 1.177100

350 t s i k i t R i l a d

Figure 4. A representative waveform and pitch trace for the phrase tsikit ʁilad ‘She missed it now’ as produced by a female speaker.

It is clear from all three figures that F0 is highest on the final syllable of the phrase, whether

the phrase consists of a single word or more than one. Comparison of figures 2 and 3 also shows

that F0 on the phrase-final syllable may either rise up to the end of the phrase as in figure 2 or

may reach a plateau prior to the end as in figure 3. As we will see, the higher F0 associated with

phrase-final syllable turns out to be quantitatively confirmed via systematic measurements.

In sections 4.1-4.4, we consider results for the measured parameters first focusing on vowels

(section 4.1) and sonorant consonants (section 4.2), the two sounds that are best suited to the

salient realization of prominence. Discussion in section 4.3 turns to voiced obstruents, which are

relatively impoverished in their ability to manifest prominence. Finally, section 4.4 addresses

voiceless obstruents, which lack the capacity to bear F0 cues to prominence.

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4.1. Vowels Figure 5 shows mean F0, duration, and intensity values for vowel nuclei (/a, i/ in the present

data) in four contexts: in the final syllable of a phrase, e.g. tsikit (leftmost bar within each graph),

in the penultimate syllable of a phrase, e.g. tsikit (second bar from the left within each graph), in

the final syllable of a phrase-medial word, e.g. tsikit ʁilad (third bar from the left within each

graph), and in the penultimate syllable of a phrase-medial word, e.g. tsikit ʁilad (rightmost bar

within each graph). F0 results for female speakers appear in the top left graph, F0 results for

male speakers in the top right graph, duration data in the bottom left, and intensity results in the

bottom right. Results for individual speakers are given in tables 1-3: F0 in table 1, duration in

table 2, and intensity in table 3.

As is evident from the figure, vowels in phrase-final syllables are characterized by higher

F0, longer duration, and greater intensity than vowels in other positions. Another pattern that

emerges is for vowels in word-final syllables that are not phrase-final to have greater intensity

and duration than vowels in the penultimate syllable. A repeated measures ANOVA for the

female speakers with F0 as the dependent variable and position (phrase-final, phrase-

penultimate, word-final, or word-penultimate) as the within-subjects independent variable

indicated a significant effect (Greenhouse-Geisser adjusted) of context on F0 for the female

speakers: F (1.765) = 10.054, p

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However, the difference between phrase-final syllables and the penult of phrase-final words was

not significant. F0 was higher in the penult of phrase-final words than in both the penult and the

ultima of phrase-medial words.

Figure 5. Mean F0 averaged over female speakers (top left) and male speakers (top right), duration averaged over all speakers (bottom left), and intensity averaged over all speakers (bottom right) for vowels in four contexts. Error bars represent 95% confidence intervals.

Phr-Fin Phr-Pen Wd-Fin Wd-Pen Phr-Fin Phr-Pen Wd-Fin Wd-Pen

Phr-Fin Phr-Pen Wd-Fin Wd-Pen Phr-Fin Phr-Pen Wd-Fin Wd-Pen

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Table 1. F0 values (in Hertz) for vowels for six speakers (three female and three male)

Phrase-final Phrase-medial Speaker Ultima Penult Ultima Penult F1 202 213 187 197 F2 278 206 253 228 F3 216 209 204 205 M1 162 143 127 129 M2 154 146 131 129 M3 125 130 129 122

Table 2. Duration values (in seconds) for vowels for six speakers (three female and three male) Phrase-final Phrase-medial Speaker Ultima Penult Ultima Penult F1 0.085 0.076 0.084 0.090 F2 0.112 0.087 0.073 0.068 F3 0.129 0.075 0.132 0.086 M1 0.127 0.070 0.106 0.093 M2 0.095 0.068 0.080 0.076 M3 0.089 0.063 0.075 0.062

Table 3. Intensity values (in decibels) for vowels for six speakers (three female and three male)

Phrase-final Phrase-medial Speaker Ultima Penult Ultima Penult F1 62.42 62.11 64.28 63.67 F2 67.75 54.21 66.51 55.85 F3 70.09 72.72 70.06 72.23 M1 68.03 69.11 65.76 68.82 M2 69.39 70.78 68.67 69.85 M3 66.53 57.77 63.77 56.82

There was some interspeaker variation in F0 results. In separate ANOVAs conducted for

individual speakers, four of the six (all except F3 and M3) displayed a significant effect of

position on F0: for speaker F1, F (3) = 25.275, p

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speakers displaying an effect of position on F0 had highest F0 in the final syllable of the phrase,

accounting for the overall result seen in the figure. One speaker (F1) displayed highest F0 values

in the penultimate syllable of the phrase. Two speakers (M1 and M2) had slightly raised F0

values in the phrase-penultimate syllable relative to the penult and ultima of phrase-medial

words. Speaker F1 displayed a different pattern, whereby the second highest F0 values (after

those in phrase-final syllables) were found in the final syllable of phrase-medial words.

A repeated measures ANOVA also found that intensity was affected by position: F (3) =

16.637, p

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duration for all speakers except F1: for speaker F2, F (3) = 10.014, p

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property and pitch accent is a phrase-level feature assigned in bottom-up fashion to select

syllables carrying word-level stress.

The relationship between duration and both stress and pitch accent is ambiguous in the

Tashlhiyt data due to the fact that stress and pitch accent in Tashlhiyt happen to fall on final

syllables, which are known to trigger lengthening independent of prominence in many languages

e.g. Arabic (de Jong & Zawaydeh 1999), Chickasaw (Gordon & Munro 2007), Dutch

(Gussenhoven & Rietveld 1992), English (Wightman et al. 1992), Finnish (Oller 1979),

Greenlandic Eskimo (Nagano-Madsen 1992), Hebrew (Berkovits 1991), Hungarian (Hockey &

Fagyal 1999), Italian (van Santen & D’Imperio 1999), and Spanish (Oller 1979). In fact, the

Tashlhiyt data displays the gradient type of lengthening characteristic of final position, whereby

lengthening is greater phrase-finally than word-finally. It is thus unclear whether stress and/or

pitch accent triggers lengthening or whether this lengthening associated with final position is an

independent phenomenon.

4.2. Sonorant consonants Figure 6 shows mean F0, duration, and intensity values for sonorant nuclei (/m, l, r/) in four

contexts: in the final syllable of a phrase, e.g. sslslt (leftmost bar within each graph), in the

penultimate syllable of a phrase, e.g sslslt (second bar from the left within each graph), in the

final syllable of a phrase-medial word, e.g. sslslt ʁilad (third bar from the left within each

graph), and in the penultimate syllable of a phrase-medial word, e.g. sslslt ʁilad (rightmost bar

within each graph). F0 results for female speakers appear in the top left graph, F0 results for

male speakers in the top right graph, duration data in the bottom left graph, and intensity results

in the bottom right graph. Results for individual speakers are given in table 4-6: F0 in table 4,

duration in table 5, and intensity in table 6.

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Figure 6. Mean F0 averaged over female speakers (top left) and male speakers (top right), duration averaged over all speakers (bottom left), and intensity averaged over all speakers (bottom right) for sonorant consonant nuclei in four contexts. Error bars represent 95% confidence intervals. Table 4. F0 values (in Hertz) for sonorant consonants for six speakers (three female and three male)

Phrase-final Phrase-medial Speaker Ultima Penult Ultima Penult F1 210 208 191 202 F2 299 213 246 219 F3 243 206 208 210 M1 182 151 139 147 M2 153 143 144 135 M3 115 123 128 126

Phr-Fin Phr-Pen Wd-Fin Wd-Pen Phr-Fin Phr-Pen Wd-Fin Wd-Pen

Phr-Fin Phr-Pen Wd-Fin Wd-Pen Phr-Fin Phr-Pen Wd-Fin Wd-Pen

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Table 5. Duration values (in seconds) for sonorant consonants for six speakers (three female and three male)

Phrase-final Phrase-medial Speaker Ultima Penult Ultima Penult F1 0.089 0.078 0.074 0.076 F2 0.109 0.096 0.095 0.091 F3 0.125 0.073 0.101 0.081 M1 0.074 0.056 0.057 0.053 M2 0.091 0.072 0.086 0.072 M3 0.083 0.073 0.067 0.067 Grand Mean 0.095 0.077 0.081 0.075 Table 6. Intensity values (in decibels) for sonorant consonants for six speakers (three female and three male) Phrase-final Phrase-medial Speaker Ultima Penult Ultima Penult F1 57.65 55.17 58.07 55.20 F2 61.85 52.29 58.88 52.97 F3 66.73 67.22 66.04 67.32 M1 58.67 58.38 57.32 57.74 M2 63.58 64.00 63.21 64.59 M3 60.23 56.16 61.28 57.80 Grand Mean 61.18 58.08 60.48 58.52

As the figure shows, results for sonorant consonants largely mirror those seen for vowels with a

couple of minor deviations. The higher F0 characteristic of phrase-final syllables is even more

evident for sonorant consonants and the lengthening characteristic of word-final vowels in

phrase-medial words is less pronounced in the case of sonorant consonants.

Looking first at F0 in more detail, a repeated measures ANOVA pooled over female

speakers indicated a significant effect of position on F0 for sonorant consonant nuclei: F (3) =

63.275, p

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All six speakers displayed an effect of position on F0 according to individual speaker

ANOVAs: for speaker F1, F (3) = 12.33, p

23

In summary, the results for sonorant consonant nuclei basically mirror those seen for vowels

and are consistent with an analysis that posits stress on word-final syllables with the final

stressed syllable of a phrase being promoted to pitch accented status.

4.3. Voiced obstruents We now turn to voiced obstruents (/Z, Â/ in the present experiment), which are less well suited to

the salient realization of prominence than sonorants. Figure 7 shows mean F0, duration, and

intensity values for voiced obstruent nuclei in four contexts: in the final syllable of a phrase, e.g.

tstÂt (leftmost bar within each graph), in the penultimate syllable of a phrase, e.g tstÂtn (second

bar from the left within each graph), in the final syllable of a phrase-medial word, e.g. tstÂt ʁilad

(third bar from the left within each graph), and in the penultimate syllable of a phrase-medial

word, e.g. tstÂtn ʁilad (rightmost bar within each graph). F0 results for female speakers appear

in the top left graph, F0 results for male speakers in the top right graph, duration data in the

bottom left graph, and intensity results in the bottom right graph. Results for individual speakers

are given in table 7-9: F0 in table 7, duration in table 8, and intensity in table 9.

24

Figure 7. Mean F0 averaged over female speakers (top left) and male speakers (top right), duration averaged over all speakers (bottom left), and intensity averaged over all speakers (bottom right) for voiced obstruent nuclei in four contexts. Error bars represent 95% confidence intervals.

Table 7. F0 values (in Hertz) for voiced obstruent nuclei for six speakers (three female and three male)

Phrase-final Phrase-medial Ultima Penult Ultima Penult F1 164 161 166 161 F2 217 204 229 213 F3 233 187 192 190 M1 157 135 108 141 M2 139 114 109 122 M3 101 103 110 107

Phr-Fin Phr-Pen Wd-Fin Wd-Pen Phr-Fin Phr-Pen Wd-Fin Wd-Pen

Phr-Fin Phr-Pen Wd-Fin Wd-Pen Phr-Fin Phr-Pen Wd-Fin Wd-Pen

25

Table 8. Duration values (in seconds) for voiced obstruent nuclei for six speakers (three female and three male) Phrase-final Phrase-medial Speaker Ultima Penult Ultima Penult F1 0.078 0.092 0.088 0.081 F2 0.148 0.133 0.125 0.134 F3 0.101 0.083 0.079 0.079 M1 0.090 0.063 0.083 0.069 M2 0.078 0.083 0.090 0.070 M3 0.125 0.111 0.131 0.112 Table 9. Intensity values (in decibels) for voiced obstruent for six speakers (three female and three male) Phrase-final Phrase-medial Speaker Ultima Penult Ultima Penult F1 50.36 48.54 50.66 48.81 F2 56.86 49.48 57.79 52.71 F3 63.03 62.76 61.17 62.96 M1 58.60 59.36 56.56 58.04 M2 58.61 58.03 58.59 58.24 M3 59.81 53.96 62.94 59.84

As the figure shows, the voiced obstruents display the same trends as those seen for the

sonorants, although the four examined contexts are in general not as well distinguished for the

voiced obstruents as they were for the sonorants. F0 is somewhat higher in phrase-final syllables

than in other positions in keeping with the pattern seen for sonorants. There is also a tendency for

intensity to be greater in word-final syllables, whether phrase-final or phrase-medial, compared

to penultimate syllables. Final lengthening at the phrase level, and, to a lesser degree, at the word

level is also apparent, although the effect of position on duration did not emerge as significant in

a repeated measures ANOVA.

Looking at the parameters that distinguished voiced obstruents by context, F0 was affected

by position for both female and male speakers: for females, F (2.017) = 6.705, p=.003; for males,

26

F (1.621) = 8.321, p=.019. F0 was higher in phrase-final syllables relative to others, although this

effect was only marginally robust in posthoc tests for female speakers: phrase-final vs. phrase-

penultimate, p=.057; phrase-final vs. word-final, p=.049; phrase-final vs. word-penultimate,

p=.013. For male speakers, the differences between phrase-final and other syllables narrowly

missed significance in posthoc tests: phrase-final vs. phrase-penultimate, p=.066; phrase-final vs.

word-final, p=.110; phrase-final vs. word-penultimate, p=.118. More importantly, although three

speakers (F3, M1 and M2) display the same trend for F0 to be raised phrase-finally, only one

speaker (F3) evinced a robust overall effect of position on F0 in individual speaker ANOVAs: F

(3) = 8.979, p

27

In summary, evidence for a pitch accent on the final syllable of phrases and stress on word-

final syllables was less clear-cut for voiced obstruents compared to sonorants, although none of

the results for voiced obstruents contradict the patterns observed in sonorants. There was a minor

tendency for voiced obstruents in phrase-final syllables to have the higher F0 characteristic of a

pitch accent, but this effect was only firmly evident for one of the six speakers. Furthermore,

only one speaker displayed the greater intensity in both phrase-final and word-final syllables that

is suggestive of stress in word-final syllables.

4.4. Voiceless obstruents Figure 8 shows mean F0, duration, and intensity values for voiceless obstruent nuclei (/f, s, x, ©/

in the present experiment) in four contexts: in the final syllable of a phrase, e.g. trkst (leftmost

bar within each graph), in the penultimate syllable of a phrase, e.g trkstn (second bar from the

left within each graph), in the final syllable of a phrase-medial word, e.g. trkst ʁilad (third bar

from the left within each graph), and in the penultimate syllable of a phrase-medial word, e.g.

trkstn ʁilad (rightmost bar within each graph). F0 results for female speakers appear in the top

left graph, F0 results for male speakers in the top right graph, duration data in the bottom left

graph, and intensity results in the bottom right graph. Results for individual speakers are given in

table 10 and 11: duration in table 10, and intensity in table 11.

28

Figure 8. Duration (left) and intensity (right) averaged over all speakers (bottom right) for voiceless obstruent nuclei in four contexts. Error bars represent 95% confidence intervals.

Table 10. Duration values (in seconds) for voiceless obstruent nuclei for six speakers (three female and three male)

Phrase-final Phrase-medial Speaker Ultima Penult Ultima Penult F1 0.112 0.102 0.108 0.096 F2 0.144 0.122 0.128 0.113 F3 0.151 0.122 0.154 0.133 M1 0.117 0.097 0.106 0.093 M2 0.105 0.092 0.098 0.098 M3 0.124 0.098 0.134 0.118 Table 11. Intensity values for voiceless obstruent nuclei for six speakers (three female and three male) Phrase-final Phrase-medial Speaker Ultima Penult Ultima Penult F1 46.97 47.12 48.82 46.99 F2 50.19 46.73 51.47 48.73 F3 56.49 60.93 56.76 59.06 M1 53.34 54.04 51.81 54.07 M2 50.48 54.63 51.37 54.95 M3 53.30 50.78 53.99 50.32

As the figure suggests, a repeated measures ANOVA over data pooled across speakers confirmed

that intensity does not reliably distinguish voiceless obstruents based on their position. This

Phr-Fin Phr-Pen Wd-Fin Wd-Pen Phr-Fin Phr-Pen Wd-Fin Wd-Pen

29

result, however, obscures considerable variation observed in individual speaker ANOVAs. Four

of six speakers (all except F1 and F2) showed a significant overall effect, albeit for some

speakers, only marginally significant, of position on intensity: for speaker F3, F (3) = 9.182,

p

30

speakers did not consistently distinguish a particular syllable as more prominent than others on

the basis of intensity.

Voiceless obstruents are subject to final lengthening in keeping with results for other more

sonorous nuclei. The degree of lengthening is, however, no greater in voiceless obstruents than

in other sounds suggesting that speakers do not rely on duration as a compensatory cue to stress

and/or pitch accent in the absence of F0 or intensity cues. On the one hand, the failure of

duration to signal prominence is perhaps surprising since it is a property that Tashlhiyt readily

manipulates to serve phonological purposes in contrasting singleton and geminate obstruents.

Ironically, however, it is perhaps the existence of these length contrasts that render duration less

available as a potential cue to prominence.1

The failure of stress and pitch accent to be clearly marked on voiceless obstruents coupled

with the less robust realization of prominence on voiced obstruents relative to sonorants raise the

interesting question of how prominence is signaled, if at all, when it is linked with syllables

containing an obstruent nucleus. In the next section, we explore this issue in the context of vowel

epenthesis, a pervasive phenomenon in Tashlhiyt.

4.5. Epenthesis As discussed in detail in work by Dell & Elmedlaoui (2002) (see also Fougeron and Ridouane

2008a,b for phonetic data), epenthesis occurs widely in Tashlhiyt potentially giving the casual

observer the impression of the existence of a fourth phonemic vowel in addition to /i, a, u/. The

epenthetic vowel is a fairly central vowel whose precise quality varies as a function of

surrounding consonants (see Coleman 1999 for phonetic data). Following Dell & Elmedlaoui,

1 We thank an anonymous reviewer for making this suggestion.

31

however, we will transcribe this vowel as schwa consistently, since its qualitative variation is not

crucial to the analysis of prominence.

In their analysis of epenthesis, Dell and Elmedlaoui (2002) focus on what they term voiced

transitional vocoids (abbreviated ‘VTV’ by them), which break up, in certain contexts, consonant

clusters consisting of at least one voiced consonant. As they point out, epenthesis is a gradient

phenomenon such that the duration of epenthetic vowels varies contextually (see Coleman 1999

for phonetic duration data) and their presence is optional in certain positions, facts that suggest

that epenthesis operates at a phonetic rather than a phonological level. Furthermore, speakers are

not typically aware of epenthetic vowels, an observation that is consistent for our consultants as

well. The interested reader is referred to the discussion in Dell and Elmedlaoui (2002:135-187)

for all the details related to epenthetic vowels whose occurrence depends on the voicing and

manner of adjacent consonants and, to a lesser extent, on morphology. The fact that epenthesis

has the hallmarks of a phonetic rather than phonological phenomenon raises interesting issues in

terms of its potential relationship to stress and pitch accent. If the epenthetic vowels are the result

of a low-level phonetic process rather than being truly phonological, they might not be expected

to serve as either the docking site for stress or pitch accent.

Our data largely confirm Dell and Elmedlaoui’s observation that VTVs are widely attested

adjacent to voiced consonants. Figure 9 illustrates an example of an epenthetic vowel between

/k/ and /m/ in tlkmt [tlkәmt] ‘you arrived’. However, we also found a number of instances of

epenthetic vowels, all of which were voiced in our data, in two other contexts: between voiceless

consonants, a context that triggers epenthesis in Tashlhiyt singing (Dell & Elmedlaoui 2008, Dell

2010), and word-finally. Figures 10 and 11 depict two docking sites for an epenthetic vowel in

32

tf.txt [tftәxt] ‘She rolled it (masc.)’: between voiceless consonants, i.e. [tftәxt], in figure 10 and

word-finally, i.e. [tftxtә], in figure 11.

Interestingly, these epenthetic vowels and, to a lesser extent, those occurring between

voiced consonants, display distributional skewings dependent on whether the word in which they

appear is phrase-final or phrase-medial and, in the case of epenthesis between consonants, on the

location of the syllable in which the flanking consonants appear.

There were six positions that were tracked in our data that potentially gave rise to

epenthesis. We did not tabulate cases of epenthesis to the left of the penult. The six epenthesis

sites are as follows, where we refer to the consonant triggering epenthesis as the actual nucleus

for purposes of defining the location of epenthesis. First, epenthesis was possible at the end of a

word, whether this word was phrase-final or phrase-medial. Epenthesis also occurred in some

tokens word-medially before the consonantal nucleus of a syllable, whether this syllable was the

penultimate or the final one of the word. Interestingly, cases of word-medial epenthesis in our

data were limited to prenuclear position before both sonorants and obstruents. This result should

not be regarded as an exceptionless property of epenthesis in the language as a whole. Dell and

Elmedlaoui (2002) identify many instances of epenthesis after a nuclear sonorant, and Dell and

Elmedlaoui (2008) report that in singing epenthetic schwa characteristically follows rather than

precedes a sonorant nucleus. Furthermore, we have also encountered epenthetic vowels in non-

prenuclear contexts in our work on the language outside of the data analyzed for this paper.

The six positions in which epenthetic vowels were found in our data are summarized in

table 12 where the target sound is /x/ in the words tf.txt (final syllable) ‘She rolled it (masc.)’ and

tf.tx.tn (penult) ‘She rolled them (masc.)’. Syllabic consonants are marked with a syllabic

33

diacritic to indicate that they are treated in the discussion as the phonological nucleus of a

syllable containing an epenthetic vowel.

Time (s)0 0.6245

0

5000 t l k @ m t

Figure 9. Epenthetic vowel between /k/ and /m/ in tlkmt [tlkәmt] ‘you arrived’

Time (s)0 0.6001

0

5000 t f t @ x t

Figure 10. Epenthetic vowel between /t/ and /x/ in tf.txt [tftәxt] ‘She rolled it (masc.)’

34

Time (s)0 0.83195

0

5000 f t x t @t

Figure 11. Phrase-final epenthetic vowel in tf.txt [tftxtә] ‘She rolled it (masc.)’ Table 12: Epenthesis sites in Tashlhiyt Berber Position of word Position of syllabic consonant Form

Penult tf`.t´x̀.tǹ Ultima tf`.t´x̀t

Phrase-final

Final tf`.tx̀.t´ Penult tf`.t´x̀.tǹ Âilad Ultima tf`.t´x̀t Âilad

Phrase-medial

Final tf`.tx̀.t´ Âilad There were a small number of instances (6) of “double epenthesis” involving an epenthetic

vowel both word-finally and before the consonantal nucleus in the final syllable, e.g. tf`.t´x`t´.

There were no instances of epenthesis in final position where the target consonantal nucleus was

in the penult, e.g. tf`.tx`.tn`´ or tf̀.t´x`.tn´. This gap is likely attributed to the presence of a final

sonorant nucleus in words in our corpus containing the target nucleus in the penult, e.g. tf̀.tx̀.tn.

The distribution of epenthetic vowels is shown graphically in figure 12, which plots the

percentage of tokens containing an epenthetic vowel in various contexts. Bars are grouped

35

according to the target nucleus for a given word with each bar in a group representing a different

context in which the target nucleus appears. The leftmost bar in each group represents cases in

which an epenthetic vowel occurs in a phrase-final word in which the target consonant occurs in

the final syllable, e.g. tf̀.t´x`t. The second bar from the left within each group represents cases in

which the epenthetic vowel occurs in a phrase-final word in which the target consonant occurs in

the penultimate syllable, e.g. tf̀.t´x`.tn. The third bar from the left reflects tokens with epenthesis

in a phrase-medial word in which the target consonant occurs in the final syllable, e.g. tf̀.t´x`t

Âilad. The rightmost bar represents instances of epenthesis in a phrase-medial word with the

target consonant in the penult, e.g. tf̀.t´x`.tn Âilad. Aside from phrase-final words containing the

target consonant in the final syllable, virtually all instances of epenthesis occur word-medially

before the target consonant. For bars that are split the lower portion of the bar indicates tokens

with word-medial, i.e. before the target consonant, epenthesis, while the upper part of the bar

represents cases of word-final epenthesis. With few exceptions, instances of word-final

epenthesis are limited to phrase-final forms in which the target consonant falls in the final

syllable (the leftmost bar), e.g. tf̀.tx`t´. The small number of tokens with double epenthesis both

before the consonantal nucleus of the final syllable and word-finally are grouped in the upper

bar. As mentioned above, there were no cases of double epenthesis in which the target consonant

occurred in the penult.

36

0.1

0.5

0.4

0.3

0.2

0.7

0.6

0.8

0.9

1.0

0

x s © Z Â m l r

PF

in u

ltim

a

PF

in p

enult

PM

ed u

ltim

a

PM

ed p

enult

PF

in u

ltim

a

PF

in p

enult

PM

ed u

ltim

a

PM

ed p

enult

PF

in u

ltim

a

PF

in p

enult

PM

ed u

ltim

a

PM

ed p

enult

PF

in u

ltim

a

PF

in p

enult

PM

ed u

ltim

a

PM

ed p

enult

PF

in u

ltim

a

PF

in p

enult

PM

ed u

ltim

a

PM

ed p

enult

PF

in u

ltim

a

PF

in p

enult

PM

ed u

ltim

a

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ed p

enult

PF

in u

ltim

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enult

PM

ed u

ltim

a

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in u

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a

Per

centa

ge

of

token

s w

/ ep

enth

esis

Figure 12. Percentage of epenthetic vowels by target consonant as a function of phrasal context and syllable position in which the target consonant occurs A number of patterns are evident in figure 12. First, epenthetic vowels are far more common

before voiced consonants. The skewing of epenthesis in favor of voiced contexts is consistent

with Dell and Elmedlaoui’s (2002) observation that voiced transitional vocoids arise when at

least one of the adjacent consonants is voiced. However, the occasional occurrence of epenthesis

in voiceless contexts in our data is not consistent with their suggestion that epenthesis fails to

occur when both of the adjacent consonants are voiceless. Second, final vowel epenthesis is

almost exclusively limited to phrase-final words in which the final nucleus is an obstruent, with

the majority of cases arising when this final obstruent nucleus is voiceless. Third, voiced nuclei

vary less than voiceless nuclei in terms of how much their epenthesis rates are affected by

syllable position and phrasal context.

The fact that final vowel epenthesis is largely confined to phrase-final words in which the

final nucleus is an obstruent finds an explanation in terms of the pitch accent observed in phrase-

final syllables containing a sonorant nucleus. A phrase-final syllable consisting of an obstruent

nucleus is poorly suited to supporting F0 information. An epenthetic vowel inserted phrase-

finally after an obstruent nucleus effectively allows for a terminal F0 peak at the end of the

37

phrase. Consistent with this account is the fact that final vowel epenthesis is most common after

voiceless obstruent nuclei, which are most impoverished in terms of their ability to carry F0

information. It is interesting to note that schwa also serves a function in carrying pitch in

Tashlhiyt singing (Dell & Elmedlaoui 2008, Dell 2010).

4.5.1. Prominence in epenthetic vowels The occurrence of epenthetic vowels raises the question of whether epenthesis is employed by

speakers as a strategy to aid in the phonetic realization of raised F0 phrase-finally or increased

intensity word-finally. To answer this question, F0 and intensity were compared for epenthetic

vowels occurring before the same nuclei targeted for study in the first half of the paper, i.e.

before nuclei in word-final syllables that were also phrase-final (e.g. tf̀.t´x`t), before nuclei in

word-final syllables that were phrase-medial (e.g. tf̀.t´x`t Âilad), before nuclei in the penult of

phrase-final words (e.g. tf`.t´x`.tn), before nuclei in the penult of phrase-medial words (tf`.t´x`.tn

Âilad), word-finally in phrase-medial words (e.g. tf̀.tx`t´ Âilad), and phrase-finally (e.g. tf̀.tx`t´).

Figure 13 shows mean F0 data for epenthetic vowels averaged across different consonantal

nuclei, including sonorants and obstruents, in different contexts for the three female speakers (on

left) and the three male speakers (on right). Individual speaker values are given in table 13. The

penult condition refers to epenthetic vowels preceding a consonantal nucleus in the penultimate

syllable, e.g. tf̀.t´x`.tn. The ultima condition refers to epenthetic vowels before a consonantal

nucleus in the final syllable, e.g. tf̀.t´x`t. The post-ultima condition refers to epenthetic vowels at

the end of a word, e.g. tf̀.tx`t´.

38

Figure 13. F0 for epenthetic vowels triggered by consonantal nuclei (sonorants and obstruents) in different contexts averaged over three female speakers (on left) and three male speakers (on right). Table 13. F0 values (in Hertz) for epenthetic vowels occurring before consonantal nuclei in different contexts. The number of tokens belonging to each category is given in parentheses.

Phrase-final Phrase-medial Post-

ultima Ultima Penult Post-

ultima Ultima Penult

F1 ---- 199 (30) 194(29) ---- 202 (29) 197 (31) F2 304 (16) 253 (36) 243 (27) 228 (7) 206 (32) 207 (16) F3 258 (5) 223 (41) 206 (38) ---- 213 (37) 208 (34) M1 203 (8) 179 (32) 150 (28) ---- 166 (31) 152 (23) M2 169 (15) 140 (12) 135 (14) ---- 134 (14) 126 (13) M3 130 (2) 130 (22) 129 (25) ---- 128 (16) 127 (15) For both the male and female speakers, epenthetic vowels occurring at the end of a word have

higher F0 than their counterpart epenthetic vowels in other positions. This result is more

meaningful for phrase-final words than phrase-medial words, since the latter displayed final

epenthetic vowels in the speech of only a single individual (F2). Epenthetic vowels occurring

Phrase-final Phrase-medial Phrase-final Phrase-medial

39

before phrase-final consonantal nuclei also had higher F0 than all other non-final epenthetic

vowels.

These two patterns were confirmed by t-tests conducted for the data from the female

speakers. Epenthetic vowels occurring at the end of phrase-final words (post-ultima condition)

had higher F0 than epenthetic vowels in all other contexts: phrase-final post-ultima vs. phrase-

final ultima, t (116) = 7.671, p

40

vs. phrase-medial penult, t (110) = 3.856, p

41

Figure 14. Intensity for epenthetic vowels triggered by consonantal nuclei in different contexts averaged over six speakers Table 14. Intensity values (in decibels) for epenthetic vowels for six speakers (three female and three male)

Phrase-final Phrase-medial Post-

ultima Ultima Penult Post-

ultima Ultima Penult

F1 ---- 61.76 61.08 ---- 61.61 60.41 F2 66.96 64.36 65.60 57.43 54.77 56.35 F3 66.88 68.99 67.42 ---- 69.79 68.57 M1 62.67 64.48 62.06 ---- 63.21 61.06 M2 67.49 63.58 64.32 ---- 66.90 64.05 M3 62.93 65.64 62.67 ---- 59.90 60.06 T-tests pooled over all speakers indicated that all epenthetic vowels appearing in phrase-final

syllables had greater intensity than those in phrase-medial words: phrase-final ultima vs. phrase-

medial ultima, t (336) = 3.960, p

42

= 3.872, p

43

Table 15. F0 values (in Hertz) for epenthetic vowels occurring before voiced obstruent nuclei in different contexts. The number of tokens belonging to each category is given in parentheses.

Phrase-final Phrase-medial Post-

ultima Ultima Penult Post-

ultima Ultima Penult

F1 ---- 187 (10) 188 (9) ---- 182 (9) 179(11) F2 301 (4) 237 (6) 239 (3) 263 (1) 194 (6) 214 (1) F3 218 (2) 230 (9) 204 (9) ---- 209 (8) 206 (8) M1 193 (1) 183 (4) 126 (2) ---- 166 (6) 152 (1) M2 159 (1) 120 (5) 125 (2) ---- 125 (5) 138 (2) M3 140 (1) 112 (2) 107 (3) ---- 120 (1) ---- For both female and male speakers, epenthetic vowels inserted at the end of words have higher

F0 than epenthetic vowels occurring in other contexts. T-tests conducted over the data from

female speakers shows that final epenthetic vowels have higher F0 than those in non-final

contexts: phrase-final post-ultima vs. phrase-final ultima, t (29) = 3.502, p=.002; phrase-final

post-ultima vs. phrase-medial ultima, t (5) = 3.881 p=.010; phrase-final post-ultima vs. phrase-

final penult, t (6) = 3.463, p=.015; phrase-final post-ultima vs. phrase-medial penult, t (5) =

4.071, p=.008. This result should be regarded with caution, however, since there are relatively

few instances of final epenthetic vowels phrase-finally and only a single case (from female

speaker F2) of a word-final epenthetic vowel in a phrase-medial word. A more robust

comparison is possible for epenthetic vowels in the ultima as compared with those in the penult.

It is evident for the female speakers that epenthetic vowels before phrase-final voiced obstruent

nuclei have higher F0 than other non-final epenthetic vowels, though this difference reaches

significance only in the comparison with phrase-medial cases: phrase-final ultima vs. phrase-

medial ultima, t (39) = 2.484, p=.017; phrase-final ultima vs. phrase-medial penult, t (37) =

2.992, p=.005. The more general pattern is for epenthetic vowels in phrase-final words, whether

in the ultima or the penult, to have higher F0 than those in phrase-medial words. One speaker

44

(F3) displays asymmetrically higher F0 in phrase-final ultimas relative to phrase-final penults

and both the ultima and penult in phrase-medial words.

For the male speakers, only M1 has higher F0 values in the ultima of phrase-final words

compared to epenthetic vowels in other contexts. For the other two male speakers, epenthetic

vowels before phrase-final obstruent nuclei do not have higher F0 than non-final epenthetic

vowels in phrase-medial words. It is conceivable that the jump in phrase-final words from the

penult to the ultima enhances the prominence of the final syllable. It should be borne in mind,

though, that these generalizations, particularly those involving the male speakers, are based on a

relatively small data set.

4.5.3. Epenthetic vowels triggered by voiceless obstruent nuclei Figure 16 shows mean F0 values for epenthetic vowels occurring before voiceless obstruent

nuclei and word-finally following a syllable containing a voiceless obstruent nucleus for female

speakers (on left) and male speakers (on right). Individual speaker mean values are given in table

16.

Figure 16. F0 for epenthetic vowels triggered by voiceless obstruent nuclei in different contexts averaged over three female speakers (on left) and three male speakers (on right)

45

Table 16. F0 values (in Hertz) for epenthetic vowels occurring before voiceless obstruent nuclei in different contexts. The number of tokens belonging to each category is given in parentheses.

Phrase-final Phrase-medial Speaker Post-

ultima Ultima Penult Post-

ultima Ultima Penult

F1 ---- ---- ---- ---- ---- ---- F2 310 (10) 297 (7) 263 (3) 223 (4) 233 (6) 224 (2) F3 264 (2) 253 (10) 206 (5) ---- 237 (9) 226 (4) M1 206 (4) 199 (8) 190 (4) ---- 167 (10) 182 (2) M2 170 (13) ---- ---- ---- ---- ---- M3 120 (1) 123 (1) ---- ---- ---- ---- Female and male speakers diverge in their results. For the females speakers displaying epenthesis

before voiceless obstruent nuclei (speakers F2 and F3), F0 values are highest for word-final

epenthetic vowels in phrase-final words, slightly lower for epenthetic vowels preceding voiceless

obstruent nuclei in the final syllable of phrase-final words and lowest in other contexts. This

result is consistent with the view that a pitch accent is associated with the final syllable of a

phrase and was confirmed in t-tests: phrase-final post-ultima vs. phrase-final ultima, t (27) =

2.764, p=.010; phrase-final post-ultima vs. phrase-final penult, t (18) = 4.293, p

46

result, however, is somewhat misleading since only a single speaker (M1) has epenthetic vowels

in more than two contexts, while another speaker (M3) has a single token containing an

epenthetic vowel in two contexts, and a third speaker only displays epenthetic vowels in final

position. For the speaker with the most complete data set (M1), F0 values are slightly higher in

both the post-ultima (206Hz) and ultima (199Hz) conditions than in the penult (190Hz). T-tests

conducted using these speaker’s data indicate that F0 in phrase-final ultimas is higher than F0 in

phrase-medial penults (t (16) = 4.095, p=.001) and that F0 in phrase-final penults is higher than

F0 in phrase-medial penults (t (12) = 2.249, p=.044.

4.5.4. Prominence in epenthetic vowels: Summary There is a strong trend in the data for epenthetic vowels to be associated with higher F0 in two

positions: word-finally in phrase-final words and in the ultima of phrase-final words. Although

this pattern is not completely consistent across the data, it is consistent with an interpretation of

epenthesis as a prominence enhancing strategy to aid in the realization of a pitch accent in

phrase-final position. It is also in line with the role of schwa as a bearer of musical notes in

singing in Tashlhiyt Berber (Dell & Elmedlaoui 2008). In the case of phrase-final sonorants,

raised F0 in the epenthetic vowel is redundant since the sonorant itself is able to realize an

increase in F0 effectively. In the case of obstruent nuclei, however, an epenthetic vowel

presumably plays a more crucial role in supporting the phrase-final F0 rise.

However, although epenthesis is common in tokens containing certain phrase-final obstruent

nuclei, notably /x, Z, Â/, epenthesis is only observed in a minority of cases for other phrase-final

obstruent nuclei in our data. Thus, epenthesis occurs in fewer than 40% of tokens containing a

phrase-final nucleus of /s/ or /©/. There is also no evidence for a compensatory relationship

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between epenthesis and intensity such that one or both of these properties is a more robust

marker of prominence in tokens lacking an epenthetic vowel. Figure 17 shows intensity values

for voiceless obstruents only in tokens lacking an epenthetic vowel. Individual speaker means

appear in table 17. It is clear that intensity is not systematically greater in either phrase-final or

word-final voiceless obstruent nuclei relative to their counterparts in the penultimate syllable. It

is thus not the case that intensity is used as a marker of prominence preferentially in syllables

lacking an epenthetic vowel.

Figure 17. Intensity values for voiceless obstruent nuclei in tokens without an epenthetic vowel averaged over six speakers Table 17. Intensity values (in decibels) for voiceless obstruent nuclei in tokens without an epenthetic vowel for six speakers (three female and three male)

Phrase-final Phrase-medial Speaker Ultima Penult Ultima Penult F1 46.58 48.10 46.73 47.11 F2 56.41 53.85 51.10 49.65 F3 62.20 61.62 64.96 62.15 M1 53.50 51.69 51.35 53.81 M2 53.95 54.07 56.06 56.04 M3 56.11 56.39 52.73 53.77

Phr-Fin Phr-Pen Wd-Fin Wd-Pen

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There is some evidence that duration more reliably differentiates phrase-final obstruent

nuclei from others in tokens lacking an epenthetic vowels. Figure 18 plots duration for voiceless

obstruent nuclei in tokens without epenthesis. Individual speaker values follow in table 18.

Figure 18. Duration values for voiceless obstruent nuclei in tokens without an epenthetic vowel averaged over six speakers Table 18. Duration values (in seconds) for voiceless obstruent nuclei in tokens without an epenthetic vowel for six speakers (three female and three male) Phrase-final Phrase-medial Speaker Ultima Penult Ultima Penult F1 .110 .118 .097 .094 F2 .202 .151 .163 .199 F3 .160 .142 .140 .135 M1 .106 .111 .099 .081 M2 .138 .097 .103 .093 M3 .137 .122 .097 .108 Duration is much greater in final position of the phrase relative to other contexts. This differs

somewhat from the aggregate data for voiceless obstruents including those triggering epenthesis

(section 4.3), which showed greater duration in both word-final and phrase-final voiceless

Phr-Fin Phr-Pen Wd-Fin Wd-Pen

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obstruents. It is conceivable that duration is enhanced phrase-finally in the absence of an

epenthetic vowel as a partial substitute for the raised F0 characteristic of the pitch accent

associated with phrase-final sonorants. However, an alternative interpretation is that the

voiceless obstruent nucleus is simply shorter when there is an epenthetic vowel, an instantiation

of the cross-linguistic tendency for the duration of individual segments to inversely correlate

with the number of segments.

5. Discussion 5.1. Pitch accent and stress in Tashlhiyt Phrase-final syllables in Tashlhiyt have been shown to be associated with higher F0 than their

counterparts in other syllables suggesting that a phonological pitch accent, H* in an

autosegmental metrical approach (Pierrehumbert 1980), docks on the final syllable of a large

intonational unit, the Intonational Phrase. This pitch accent is most consistently present in

phrase-final sonorant nuclei and is variably associated with voiced obstruent nuclei. A virtue of

assuming a phrase-final pitch accent in Tashlhiyt is that it is consistent with standard

assumptions that each Intonational Phrase contains at least one metrically prominent syllable.

Cross-linguistic studies have shown that phrasal pitch accents characteristically dock on syllables

that are metrically prominent at the word level. Based on the data examined here, Tashlhiyt

appears to conform to the English-type (and cross-linguistically common) pattern whereby the

rightmost stress in the Intonational Phrase is promoted to pitch accent status under neutral

semantic conditions. Further research on the intonational system of Tashlhiyt is needed to

determine whether this generalization holds under different conditions, e.g. different intonational

contours, other pitch accents, different focus conditions, etc. Additional research is also

necessary to explore the relationship between the pitch accent and any boundary tones associated

50

with the Intonational Phrase. Another possibility to address in future work is whether the raised

F0 seen in final syllables could be a property of a smaller domain than the Intonational Phrase,

such as the Accentual Phrase, as in French (Jun and Fougeron 1995) or Korean (Jun 1993).

The data presented here is also insufficient to rule out the possibility that the heightened F0

on phrase-final syllables is at least partially attributed to a high boundary tone, H%. One possible

analysis that seems less compelling, however, in light of the present data is one that assumes

only H% without an accompanying H* pitch accent. Since intensity independently argues for

stress on word-final syllables, assuming an additional layer of phrase-level prominence in the

form of a pitch accent is consistent with standard assumptions about the hierarchical nature of

prominence relations. The rising F0 profile within the final syllable observed in figures 2 and 3

could be attributed to a late realization of H* possibly coupled with an upward movement to

reach the H%, if one is present.

Despite the compelling evidence from sonorants for a phrase-final pitch accent, the role of

pitch accents is more ambiguous in the case of obstruents. Although, the raised F0 observed in

phrase-final sonorants exists as a weaker effect in voiced obstruent nuclei, voiceless obstruents

did not show any evidence for special prominence on either phrase-final or word-final syllables

beyond the general pattern of final lengthening that also characterizes sonorants and voiced

obstruents and is plausibly independent of stress. This raises the question of whether a pitch

accent is phonologically associated or not with a syllable containing a phrase-final voiceless

obstruent nucleus and no epenthetic vowel. Assuming that all phrase-final syllables are accented,

this accent appears based on the present experiment to be phonetically vacuous when associated

with a voiceless obstruent and realized only in tokens containing an epenthetic vowel.

Alternatively, it is conceivable that the pitch accent fails to associate with voiceless obstruents, a

51

situation that would represent the intonational analog to tone languages that restrict tones to more

sonorant nuclei (Zhang 2002). Yet another possibility that cannot be definitively rejected is that

the pitch accent has an alternative as yet undiscovered phonetic realization when associated with

voiceless obstruents.

In any event, whether one assumes that voiceless obstruents may bear a pitch accent or not,

the lengthening of phrase-final syllables likely provides crucial perceptual evidence to the

listener that the speaker has reached the end of an Intonational Phrase. When the final syllable

nucleus of the Intonational Phrase contains a sonorant or, to a lesser extent, a voiced obstruent,

the phrase boundary is reinforced by the pitch accent. When the final syllable nucleus of the

Intonational Phrase consists of a voiceless obstruent, on the other hand, final lengthening

presumably plays a decisive role in cuing the right edge of the phrase.

Sonorant nuclei also provided evidence for word-level stress. In word-final syllables,

whether phrase-final or phrase-medial, sonorants are characteristically realized with greater

intensity than sonorants in penultimate syllables suggesting the presence of stress on the final

syllable of a word. The reliance on intensity to cue word-level stress is consistent with data from

English and Dutch (Sluijter and van Heuven 1996a,b), although Tashlhiyt appears to differ from

these languages in marking stress through an increase in overall intensity rather than an increase

in intensity localized to higher frequencies.

There are, however, a number of facts that suggest that stress has a more minor role in the

prosodic system of Tashlhiyt than pitch accents. First, greater intensity was observed in

sonorants in word-final syllables but not in obstruents, which did display some evidence for pitch

accents when voiced. Furthermore, the distribution and the phonetic realization of epenthetic

vowels in Tashlhiyt suggest that pitch accents have a privileged status relative to stress.

52

Epenthetic vowels are far less prevalent in word-final syllables that are not pitch accented, i.e.

those in phrase-medial position. Furthermore, epenthetic vowels in word-final syllables, both

phrase-medial and phrase-final, do not have reliably greater intensity than those in other

positions. These facts, coupled with the less pervasive nature of word-final lengthening relative

to phrase-final lengthening, are consistent with the view that F0 and large intonational

boundaries perform more salient communicative functions than intensity and word boundaries.

The importance of phrasal constituents in the present experiment is also in line with Dell and

Elmedlaoui’s (2002) observation that phrasal boundaries are prosodically more conspicuous than

word boundaries in Tashlhiyt.

5.2. Epenthesis as a phonological vs. phonetic phenomenon

Epenthetic vowels inserted either before or after a phrase-final consonantal nucleus are

characteristically realized with raised F0, suggesting that they may also bear pitch accents

parallel to consonantal nuclei. This raises interesting issues about the phonological status of

epenthetic vowels. On the one hand, they behave as if they are not truly phonological but rather

are the result of a phonetic implementation process operating on a surface level. Epenthetic

vowels are prosodically invisible to syllabification and the metrical system, speakers are

typically unaware of their existence, and they are characterized by the temporal and qualitative

gradience one would expect from a vowel that is not phonologically present. These

characteristics are consistent with the type of inserted vowels that Hall (2006) classifies as

“intrusive”, as opposed to true “epenthetic” vowels, which interact with other phonological

processes. Hall, in fact, referring to Dell & Elmedlaoui’s work on the language, cites Tashlhiyt

as a language instantiating the intrusive class of inserted vowels.

53

However, if the vowels added in pitch accented positions in Tashlhiyt are truly intrusive

rather than epenthetic in a phonological sense, they would not be expected to serve as the

docking site for a phonological pitch accent. One possible approach that would maintain an

analysis of the inserted vowels as phonetic rather than phonological would be to assume that the

pitch accent docks on the consonantal nucleus rather than the epenthetic vowel itself, which is

merely present to enhance the phonetic realization of the accent. This assumption is defensible in

the case of epenthetic vowels before voiced consonants since both the epenthetic vowels and the

voiced consonant are phonetically associated with higher F0 when pitch accented. Interestingly,

our data displayed interspeaker variation in whether F0 is higher in a nuclear voiced consonant

or a preceding epenthetic vowel in pitch accented syllables. Table 18 shows mean F0 values in

sequences of an epenthetic vowel plus nuclear consonant, both sonorant and obstruent, in pitch

accented syllables, i.e. phrase-final ones, for the six speakers.

Table 17. F0 values (in Hertz) for the epenthetic vowel and an immediately following voiced consonantal nucleus in pitch accented syllables for six speakers (three female and three male) V + Sonorant V + Voiced obstruent Speaker Epenthetic V Sonorant Epenthetic V Voiced

obstruent F1 206 211 187 164 F2 250 299 237 257 F3 215 250 230 233 M1 171 190 183 154 M2 154 154 120 147 M3 132 116 112 103

Individual speaker t-tests show that, in the case of vowel plus sonorant sequences, three

speakers (F2, F3, M1) have higher F0 values on the sonorant, one (M3) has higher F0 on the

epenthetic vowel, and one (F1) has virtually identical values on both segments. In vowel plus

voiced obstruent strings, t-tests showed that the only reliable differences in F0 were found for

54

speakers F1 and M1, both of whom had higher F0 on the epenthetic vowel than the obstruent.

Given the variation between speakers, it is not entirely clear whether the pitch accent is

phonologically associated with an epenthetic vowel or the following consonantal nucleus.

In the case of a voiceless consonant preceded by an epenthetic vowel, adopting an approach

whereby the pitch accent phonologically docks on the consonant itself but is realized

phonetically on a preceding epenthetic vowel would clearly entail a degree of abstraction.

Furthermore, in all cases of absolute phrase-final epenthesis, whether triggered by a voiced or a

voiceless consonant, the epenthetic vowel would not be adjacent to the voiceless consonant

phonologically bearing the pitch accent. These facts suggest that inserted vowels that are

phonetically pitch accented are also phonologically associated with an accent, i.e. are true

epenthetic vowels in Hall’s (2006) sense. Furthermore, the fact that epenthesis triggered by

voiceless consonants is heavily skewed in favor of phrase-final contexts suggests an awareness

by speakers of epenthesis as a strategy for enhancing the manifestation of the pitch accent. This

relationship between the pitch accent and epenthesis in Tashlhiyt has an analog in Japanese, in

which high vowel devoicing is inhibited in pitch accented syllables in isolated words (see

Nagano-Madsen 1994 for an overview). The Japanese case differs from Tashlhiyt in that the

pitch accent in Japanese is lexical as opposed to phrasal in Tashlhiyt. In both languages,

however, the importance of signaling F0 information impacts the likelihood of a vowel

surfacing, either by encouraging epenthesis as in Tashlhiyt or by discouraging syncope as in

Japanese. The crucial role of epenthetic vowels in cuing F0 information is not confined to the

spoken language in Tashlhiyt. Dell & Elmedlaoui (2008) and Dell (2010) show that epenthetic

vowels often serve as the docking site for notes in Tashlhiyt singing, a genre in which the

55

importance of pitch information is further underscored by the triggering of epenthesis by

voiceless consonants.

In summary, the most plausible approach to vowel insertion in Tashlhiyt would appear to

assume that there are two types of non-underlying vowels that surface. One type, described by

Dell & Elmedlaoui and triggered by voiced consonants, falls under the rubric of an “intrusive”

vowel that is inserted at the phonetic level and is transparent to the phonology. The other type,

employed in pitch accented contexts, is a true “epenthetic vowel” that has a deeper phonological

role in the prosodic system even if it eludes native speaker intuitions. Assuming two types of

epenthetic vowels in the same language would not be unique to Tashlhiyt. Hall (2006) discusses

two languages, Mono and the Cobán dialect of Kekchi, in which both intrusive and epenthetic

vowels co-exist, with the former being a low-level phonetic phenomenon and the latter playing a

more central role in the phonology.

6. Summary Investigation of three potential acoustic correlates of prominence (F0, intensity, and duration)

found that phrase-final syllables were associated with higher F0 than other syllables, suggesting

the presence of a H* pitch accent phrase-finally. The pitch accent is phonetically more salient

when associated with sonorant nuclei than voiced obstruent nuclei. Voiceless obstruent nuclei in

phrase-final syllables failed to display any phonetic evidence for a pitch accent, although they

often triggered vowel epenthesis, which allowed for the realization of the accent. In addition to

the raised F0 characteristic of phrase-level pitch accent, word-final syllables were characterized

by greater intensity than their counterparts in the penultimate syllable of a word, a finding that is

consistent with an interpretation of stress on final syllables. Phrase-final and, to a lesser degree,

word-final nuclei were consistently lengthened whether a sonorant or an obstruent and whether

56

voiced or voiceless. This final lengthening likely plays a role, in fact a crucial role in the case of

phrases with a voiceless nucleus in the final syllable, in signaling prosodic boundaries.

Acknowledgments The authors wish to thank three anonymous reviewers and Ken de Jong for their many helpful comments and suggestions on an earlier draft of this paper. We are also grateful to members of the 2009-2010 Field Methods class at UC Santa Barbara and an audience at the UCLA Phonology Seminar for their feedback on this research. A special debt of gratitude is owed to the speakers who generously contributed the data analyzed in this paper. References Adisasmito–Smith, Niken & Abigail C. Cohn. 1996. Phonetic correlates of primary and

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