9.35 sensation and perception spring 2009 for information about … · 2020. 7. 10. · diana...

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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


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.


Auditory stream



Stream segregation

• Proximity

• Continuity

• Similarity

• Symmetry and closure


Multiple sounds

adapted from Handel figure 7.4


Freq

uenc

y

Time


Multiple sound organization

• Tone sequences - Vary parameters to cause perception of

subsequences

• Conflicting organizations - Ambiguous sequences that put strategies in

conflict


Proximity



Results

from van Noorden, 1975


15

10

5

00 50 100 150 200

Tone repetition time

Freq

uenc

y se

para

tion

(sem

itone

s)

(m sec)


J.S. Bach

• Toccata and Fugue in D Minor ~1700


J.S. Bach

• Toccata and Fugue in D Minor ~1700


#

#

#(c)


Similarity

• Sounds are grouped by timbre


Similarity

• Sounds are grouped by timbre

Example

from Music, Cognition, and Computerized Sound, ed. Perry Cook


Competing organizations

Bregman and Pinker, 1978


Freq

uenc

y

Time

A

B

C


Scale illusion

• Deutsch, 1975


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


Scale illusion

• Deutsch, 1975

Demo



LLLL LL

LL LL LL LLLLRR

RRRR RR

RRRR RR

RR

RRLLLL

LL LL LL LLLL

LL

RR RR

RR RRRR RR

RR


Scale illusion

• Deutsch, 1975



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



Continuity

Kluender and Jenison 1992 - glides


Sound

Time Time

Freq

uenc

y

Noise Noise


Continuity

adapted from Bregman, 1990


Restoration

• Sasaki (1980) - familiar piano melodies

• Warren and Sherman (1974) - the *eel fell off the car - The *eal fell off the table


Frequency Graphs



Melodies Diana Deutsch, 1972


Melodies

melody 1

Diana Deutsch, 1972


Melodies

melody 1

melody 2

Diana Deutsch, 1972


Music


Music

guitar and sax


Music and Speech Perception

Kimo Johnson April 29, 2008


Linguistic universals

• Discreteness • Semanticity • Arbitrariness • Openness • Duality of patterning

Hockett, 1963


Music grammars

• Discreteness: N pitches per octave • Semanticity: scales, chords, keys • Arbitrariness • Openness • Duality


Octave

• Frequency ratio 2:1 • Greatest number of identical

overtones

• First overtone is 2 : 1


Sensory dissonance

Plomp and Levelt, 1965


"Roughness"

"Two tones"

"Beats"

Sens

ory

diss

onan

ce

12-tet scale steps:Fourth frequency Octave

Fifth interval


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


Pythagorean comma C

G

D

A

E

B

F!

C!

G!

E"

B"

F

C′

f1 = 3 2

f0

fi = 3 2

fi−1


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


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


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


Other tuning systems

• Just diatonic • Meantone (1400) • Well-temperaments

- Werckmeister (1645-1706) - Young (1773-1829)

• Equal temperament (~1900)


Optimal well-temperament

Polansky et. al, 2008


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


9.35 sensation and perception spring 2009 for information about … · 2020. 7. 10. · diana...

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