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9.35 Sensation And Perception Spring 2009
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Auditory Scene Analysis
Kimo Johnson April 23, 2009
Tuesday, April 28, 2009
• Source segregation - Spatial separation - Spectral and temporal qualities
• Stream segregation - proximity: frequency or time - continuity: follow trajectory - similarity: frequency, timbre, intensity - symmetry and closure
Auditory scene analysis
Tuesday, April 28, 2009
Single sound organization
adapted from Handel figure 7.2 Tuesday, April 28, 2009
Figure by MIT OpenCourseWare.
Sync
hron
y of
ons
ets
Har
mon
ic o
vert
ones
Segregation of fusion
Segregation
Fusion
Har
mon
ic in
tens
ities
2f
2f1.6f
1f
1f
Old-plus-new heuristic
Figures removed due to copyright restrictions.
Tuesday, April 28, 2009
Auditory stream
Figures removed due to copyright restrictions.
Tuesday, April 28, 2009
Stream segregation
• Proximity
• Continuity
• Similarity
• Symmetry and closure
Tuesday, April 28, 2009
Multiple sounds
adapted from Handel figure 7.4
Tuesday, April 28, 2009
Freq
uenc
y
Time
Figure by MIT OpenCourseWare.
Multiple sound organization
• Tone sequences - Vary parameters to cause perception of
subsequences
• Conflicting organizations - Ambiguous sequences that put strategies in
conflict
Tuesday, April 28, 2009
Proximity
Tuesday, April 28, 2009
Figure by MIT OpenCourseWare.
Results
from van Noorden, 1975
Tuesday, April 28, 2009
15
10
5
00 50 100 150 200
Tone repetition time
Freq
uenc
y se
para
tion
(sem
itone
s)
(m sec)
Figure by MIT OpenCourseWare.
J.S. Bach
• Toccata and Fugue in D Minor ~1700
Tuesday, April 28, 2009
J.S. Bach
• Toccata and Fugue in D Minor ~1700
Tuesday, April 28, 2009
#
#
#(c)
Figure by MIT OpenCourseWare.
Similarity
• Sounds are grouped by timbre
Tuesday, April 28, 2009
Similarity
• Sounds are grouped by timbre
Example
from Music, Cognition, and Computerized Sound, ed. Perry Cook
Tuesday, April 28, 2009
Competing organizations
Bregman and Pinker, 1978
Tuesday, April 28, 2009
Freq
uenc
y
Time
A
B
C
Figure by MIT OpenCourseWare.
Scale illusion
• Deutsch, 1975
Tuesday, April 28, 2009
Part 1 Part 2Part 1 Part 2
LLLL LL
LL LL LL LLLLRR
RRRR RR
RRRR RR
RR
RRLLLL
LL LL LL LLLL
LL
RR RR
RR RRRR RR
RR
Figure by MIT OpenCourseWare.
Scale illusion
• Deutsch, 1975
Demo
Tuesday, April 28, 2009
Part 1 Part 2Part 1 Part 2
LLLL LL
LL LL LL LLLLRR
RRRR RR
RRRR RR
RR
RRLLLL
LL LL LL LLLL
LL
RR RR
RR RRRR RR
RR
Figure by MIT OpenCourseWare.
Scale illusion
• Deutsch, 1975
Tuesday, April 28, 2009
Part 1 Part 2Part 1 Part 2
LLLL LL
LL LL LL LLLLRR
RRRR RR
RRRR RR
RR
RRLLLL
LL LL LL LLLL
LL
RR RR
RR RRRR RR
RR
Demo
Part 3Part 3
Demo
Figure by MIT OpenCourseWare.
Figure by MIT OpenCourseWare.
Continuity
Kluender and Jenison 1992 - glides
Tuesday, April 28, 2009
Sound
Time Time
Freq
uenc
y
Noise Noise
Figure by MIT OpenCourseWare.
Continuity
adapted from Bregman, 1990
Tuesday, April 28, 2009
Continuity
adapted from Bregman, 1990
Tuesday, April 28, 2009
Restoration
• Sasaki (1980) - familiar piano melodies
• Warren and Sherman (1974) - the *eel fell off the car - The *eal fell off the table
Tuesday, April 28, 2009
Frequency Graphs
Figures removed due to copyright restrictions.
Tuesday, April 28, 2009
Melodies Diana Deutsch, 1972
Tuesday, April 28, 2009
Melodies
melody 1
Diana Deutsch, 1972
Tuesday, April 28, 2009
Melodies
melody 1
melody 2
Diana Deutsch, 1972
Tuesday, April 28, 2009
Music
Tuesday, April 28, 2009
Music
guitar and sax
Tuesday, April 28, 2009
Music and Speech Perception
Kimo Johnson April 29, 2008
Tuesday, April 28, 2009
Linguistic universals
• Discreteness • Semanticity • Arbitrariness • Openness • Duality of patterning
Hockett, 1963
Tuesday, April 28, 2009
Music grammars
• Discreteness: N pitches per octave • Semanticity: scales, chords, keys • Arbitrariness • Openness • Duality
Tuesday, April 28, 2009
Octave
• Frequency ratio 2:1 • Greatest number of identical
overtones
• First overtone is 2 : 1
Tuesday, April 28, 2009
Sensory dissonance
Plomp and Levelt, 1965
Tuesday, April 28, 2009
"Roughness"
"Two tones"
"Beats"
Sens
ory
diss
onan
ce
12-tet scale steps:Fourth frequency Octave
Fifth interval
Figure by MIT OpenCourseWare.
Local consonance
Sethares, 1993 Tuesday, April 28, 2009
Am
plitu
de
Frequency
Unison
Sens
ory
diss
onan
ce
12-tet scale stepsm3
1/1 6/5 5/4 4/3 3/2 5/3 2/1
M3 fourth fifth M6 Octave
Frequency ratio
Figure by MIT OpenCourseWare.
Pythagorean comma C
G
D
A
E
B
F!
C!
G!
E"
B"
F
C′
f1 = 3 2
f0
fi = 3 2
fi−1
Tuesday, April 28, 2009
Pythagorean comma C
G
D
A
E
B
F!
C!
G!
E"
B"
F
C′
f1 = 3 2
f0
fi = 3 2
fi−1
( 3 2
)12 ≈ 27
312
219 ≈ 1.0136
Tuesday, April 28, 2009
Pythagorean tuning
C C# D Eb E F F# G G# A Bb B1/ 256/ 9/ 32/ 81/ 4/ 729/ 3/ 128/ 27/ 16/ 243/1 243 8 27 64 3 512 2 81 16 9 128
C : E = 81/64 = 1.2656C : E = 5/4 = 1.25
C : Eb = 32/27 = 1.1852C : Eb = 6/5 = 1.20
C# : F# = 1.3515 ≠ 1.333
Tuesday, April 28, 2009
Pythagorean tuning
C C# D Eb E F F# G G# A Bb B1/1
256/243
9/8
32/27
81/64
4/3
729/512
3/2
128/81
27/16
16/9
243/128
C : E = 81/64 = 1.2656C : E = 5/4 = 1.25
C : Eb = 32/27 = 1.1852C : Eb = 6/5 = 1.20
wolf
C# : F# = 1.3515 ≠ 1.333
Tuesday, April 28, 2009
Other tuning systems
• Just diatonic • Meantone (1400) • Well-temperaments
- Werckmeister (1645-1706) - Young (1773-1829)
• Equal temperament (~1900)
Tuesday, April 28, 2009
Optimal well-temperament
Polansky et. al, 2008
Tuesday, April 28, 2009
16
14
12
10
8
Tem
perin
g of
maj
or tr
iad
6
4
2
Eb Bb F C G D A E B F# C# G#Major triad
OWT2
OWT1Y2
W3
Figure by MIT OpenCourseWare.