1. Psycholinguistics Lecture 7
Speech Perception II

2. Announcements Midterm, Nov. 1st!
Covers material up to October 25th
October 25th (by 11:59pm): submit potential exam questions.
Form groups of 1-2 students
list 5 major points covered in the course
submit 5 short essay questions.
the questions you submit will count for 1/3 of your final midterm grade.
October 30th part new stuff, part review.

3. What is Categorical Perception?
Review
What is Categorical Perception? ba da ga
Frequency (Hz)
Time (msec)
-1->0, +2->+3

4. Methods for Testing Categorical Perception
Continuation on Categorical Perception
Methods for Testing Categorical Perception
Identification
Randomly play the audio clips and asked to identify the phoneme
Discrimination
Randomly play pairs and asked to make Same-different Judgment
Same pairs
Different pairs

5. Identification Identification
Continuation on Categorical Perception
Identification
Identification
Randomly play the audio clips and asked to identify the phoneme
If there is CP, what should the graph look like?
X-axis stimuli arranged in a continuum with very small incremental difference between the stimuli
Y-axis % Identification as the tested category

6. Identification (idealized results)
Continuation on Categorical Perception
Identification (idealized results)
100 80 60
% Identification as Category X 40 20 1 2 3 4 5 6 7
Stimulus #

7. Discrimination Study Last lecture:
Continuation on Categorical Perception
Discrimination Study
Last lecture:
The ba/da/ga study varied transitional state (up, down of F2).
In this example, Varying Voice Onset Time.

8. Voice Onset Time (VOT) [b] [p]
Continuation on Categorical Perception
Voice Onset Time (VOT)
VOT: time between consonant release and vocal cord vibration
[b]
[p]
So what is the difference in VOT between VOICELESS [b] and VOICED [p]?
SHORT VOT  voiced
LONG VOT  voiced

9. Voice Onset Time (VOT) Short VOT = ? Long VOT = ?
Continuation on Categorical Perception
Voice Onset Time (VOT)
Short VOT = ?
Long VOT = ?
Which one is /di/ and which one is /ti/? di ti

10. Discrimination Study Same/Different? 0ms 60ms Same/Different?
Continuation on Categorical Perception
Discrimination Study
Same/Different?
0ms ms
Same/Different?
Why is this pair difficult?
0ms ms
(i) Acoustically similar?
(ii) Same Category?
Same/Different?
40ms 40ms

11. Discrimination A More Systematic Test D D D T T T Same/Different
Continuation on Categorical Perception
Discrimination
A More Systematic Test
Same/Different D D
0ms ms
0ms
20ms D
20ms
40ms T
Same/Different
0ms ms T T
40ms
60ms
Same/Different
Within-Category Discrimination is Hard
40ms 40ms

12. Categorical Perception (Idealized Discrimination Data)
Continuation on Categorical Perception
Categorical Perception (Idealized Discrimination Data)
100 80 60
% Correct Discrimination 40 20
1-2
2-3
3-4
4-5
5-6
Pairs by VOT

13. What researchers found…
Contrast
Major Acoustic Cue
Place in oral stops [ba-da-ga]
Start and direction of the second formant
Word initial voicing in oral stops [ba-pa]
Voice Onset Time
Place in fricative [sa-ša]
Frequency of the turbulent noise
Word final voicing in oral stops [ab-ap]
Duration of preceding vowel
Voice in final fricative [as-az]
Place in nasal stops [ma-na]

14. Where did our speech perception abilities come from?
Motor Theory vs. Auditory Theory
Where did our speech perception abilities come from?
The Motor Theory:
– perception is informed by our innate knowledge of articulation
The Auditory Theory:
– speech perception is based solely on auditory properties of speech

15. Contrasting the two theories
Motor Theory vs. Auditory Theory
Contrasting the two theories
The Motor Theory
The Auditory Theory
Perception is based on production (i.e., understanding of articulatory gestures speakers make)
Perception is based on genetic auditory mechanisms
Perception is species-specific
Speech production and perception evolved together
Perception is not species-specific
Production system evolved by making use of existing auditory capacities
Perception is innate
Tacit knowledge of articulation is given by evolution
Perception could be innate or learned
(slides adapted from J. Snedeker, C. Phillips)

16. Questions to Ask The Motor Theory QUESTIONS
Motor Theory vs. Auditory Theory
Questions to Ask
The Motor Theory
QUESTIONS
Perception is based on production (i.e., understanding of articulatory gestures speakers make)
Q3. Is speech perception affected by knowledge of articulation?
Perception is species-specific
Speech production and perception evolved together
Q2. Is speech perception species-specific?
Perception is innate
Tacit knowledge of articulation is given by evolution
Q1. Is speech perception innate?
(slides adapted from J. Snedeker, C. Phillips)

17. Question 1 Is speech perception innate?
Motor Theory vs. Auditory Theory Question 1
Question 1
Is speech perception innate?
Do newborns have categorical perception?
If CP requires exposure to language (e.g., knowledge of minimal pairs in one’s language), then NO.
If CP is innate, then YES.
How do we test newborns?

18. High Amplitude Sucking Procedure
Motor Theory vs. Auditory Theory Question 1
High Amplitude Sucking Procedure
Infant given a pacifier that measures sucking rate
Habituation – Infant sucks to hear sound (e.g. ba) until bored.
Test – Play sound (e.g., ba or pa). Is there dishabituation?
Infants will suck to hear sound if the sound is no longer boring.
(2:50 min. into videoclip)

19. Stimuli for Eimas et. al’s Study
Motor Theory vs. Auditory Theory Question 1
Stimuli for Eimas et. al’s Study
BA vs. PA
Vary Voice Onset Time (VOT): time btw consonant release and vocal cord vibration BA PA 20 40 60 80
VOT in milliseconds

20. Predictions Between Category BA1-PA Within Category BA1-BA2 Control
Motor Theory vs. Auditory Theory Question 1
Predictions
Between Category
BA1-PA
Within Category
BA1-BA2
Control
BA1-BA1
Innate Categorical Perception
dishabituate
remain habituated
Untuned Sensitivity
Insensitive
BA1 = VOT 20ms; BA2 = VOT 0ms; PA = VOT 40ms

21. Results for Eimas et. al’s Study
Motor Theory vs. Auditory Theory Question 1
Results for Eimas et. al’s Study
dishab no
MEAN NUMBER OF SUCKING RESPONSE no
For Other examples, see Werker

22. Question 1 Answer Q1: Is Speech Perception Innate?
Motor Theory vs. Auditory Theory Question 1
Question 1 Answer
Q1: Is Speech Perception Innate?
Many other studies since tested:
Infants (Neonates) on other contrasts.
Consensus: Yes to Innate Q.
Infants do not discriminate all physically equal acoustic difference; they show heightened sensitivity to those that are important for language.
BUT… there is language-specific fine-tuning…
Many Studies: e.g., Werker – assigned paper.
Neonates on sounds clearly not distinguishable in womb

23. Motor vs. Auditory Theory Score card
Motor Theory vs. Auditory Theory Question 1
Motor vs. Auditory Theory Score card
Q1: Is Speech Perception Innate?
Answer: YES.
Predicted by Motor Theory
Speech perception driven by innate knowledge of articulation
Consistent with Auditory Theory
Speech perception due to innate structure of auditory system

24. Question 2 Is speech perception species-specific?
Motor Theory vs. Auditory Theory Question 2
Question 2
Is speech perception species-specific?
Do other animals show categorical perception on the same speech sounds?
How do we test animals? ?

25. Avoidance Conditioning Procedure
Motor Theory vs. Auditory Theory Question 2
Avoidance Conditioning Procedure
Kuhl & Miller (1978): test chinchillas and humans with identical stimuli
Human Task: identification (d or t)
Chinchillas: avoidance conditioning

26. Avoidance Conditioning Procedure
Motor Theory vs. Auditory Theory Question 2
Avoidance Conditioning Procedure
Speech sound at one end of the continuum paired with shock
Other end paired with safety
Safety
Shock 20 40 60 80
VOT

27. Avoidance Conditioning Procedure
Motor Theory vs. Auditory Theory Question 2
Avoidance Conditioning Procedure
Animals learn to “avoid” shock.
What will they do for between cases?
Safety ? ? ? ? ? ?
= FLEE
Chamber divided. Keep drinking, but when hear shock, run…
Shock
= STAY 20 40 60 80
VOT

28. Predictions Motor Theory vs. Auditory Theory Question 2 100
Categorical Perception
Graded Perception 80 60
% Identification as [d] 40 20 1 2 3 4 5 6 7
Stimulus #

29. Motor Theory vs. Auditory Theory Question 2
Kuhl & Miller (1978)

30. Motor vs. Auditory Theory Score card
Motor Theory vs. Auditory Theory Question 2
Motor vs. Auditory Theory Score card
Q2: Is Speech Perception Species-Specific?
Answer: NO.
Contrary to Motor Theory Claim
That is, only humans have (innate or learned) knowledge of articulation
Consistent with Auditory Theory
General auditory abilities adequate for (some aspects of) speech perception

31. Some species-specific aspects of speech perception
Motor Theory vs. Auditory Theory Question 2
Some species-specific aspects of speech perception
Other primates (e.g., Macaques, vervet monkeys, chimpanzees)
Boundary of ra/la not human like (Sinnott & Brown, 1997)
Fail to make use of vowel length in consonant discrimination (Sinnott, Brown, & Borneman, 1998)
Fail to use formant transitions alone in consonant discrimination (Sinnott & Williamson, 1999)
Fail to categorize two different vowels in the same way infants learn to categorize those two vowels (Kuhl, 1991)
Different similarity space for vowels (Sinnot, Brown, Malik, & Kressley, 1997; Kojima & Kiritani, 1989)

32. Motor Theory vs. Auditory Theory Question 3
Is speech perception based on our knowledge of articulation?
Would knowledge of:
Visual information of mouth movements
Coarticulation
influence our speech perception?
What experiments?
McGurk Effects
Co-articulation Experiments

33. McGurk Effect Audio Visual Your Perception ba va tha ga da
Motor Theory vs. Auditory Theory Question 3
McGurk Effect
Audio
Visual
Your Perception ba va
tha ga da

34. Motor Theory vs. Auditory Theory Question 3
McGurk Effect
McGurk Finding: phoneme categorization is affected by visual information
audio BA + visual GA = percept DA
Q3: Is speech perception based on our knowledge of articulation?
YES. Adult speech perception is affected by visual cues.
Are infants?

35. Motor Theory vs. Auditory Theory Question 3
Three Infant Studies
Do infants make use of visual cues to articulation?
Kuhl & Meltzoff (1982)
Rosenblum, Lawrence, Schmuckler, & Johnson (1997)
Burnham & Dodd (2004)

36. Kuhl & Meltzoff (1982) Preferential Looking Paradigm Familiarlization:
Motor Theory vs. Auditory Theory Question 3
Experiment 1
Kuhl & Meltzoff (1982)
Preferential Looking Paradigm
Familiarlization:
[a] and [i] face
NO AUDIO
Test Phase:
AUDIO of either [a] or [i]
MEASURE: looking time to appropriate face.

37. Kuhl & Meltzoff (1982) Do infants know visual cues to articulation?
Motor Theory vs. Auditory Theory Question 3
Experiment 1
Kuhl & Meltzoff (1982)
Do infants know visual cues to articulation?
Kuhl & Meltzoff (1982)
Show that 4-5 months-old infants can match sound with correct mouth shape
But not evidence of visual cues influencing categorization
Kuhl & Meltzoff, 1982

38. Rosenblum et al. (1997) Tested 5-months-old infants
Motor Theory vs. Auditory Theory Question 3
Experiment 2
Rosenblum et al. (1997)
Tested 5-months-old infants
Habituated on audio VA & visual VA
Tested on
(1): Audio BA & Visual VA (adults perceive as VA)
(2): Audio DA & Visual VA (adults perceive as DA)
Results
Dishabituate to (1)? (2)?
Infants dishabituate only to (2)
Show?
Infants are like adults!
They are sensitive to visual cues to articulation.
Infant actually sat on parent’s lap.
Habituation phase – played video until infant is bored.
Then switch video.

39. Burnham & Dodd (2004) Tested 2 groups of ½ months-old infants
Motor Theory vs. Auditory Theory Question 3
Experiment 3
Burnham & Dodd (2004)
Tested 2 groups of ½ months-old infants
Test Group:
habituation
Audio BA
Visual GA
Control Group: habituation
Audio BA
Visual BA
Both groups then tested on:
(1) audio BA; (2) audio DA; (3) audio THA
Results: Dishabituation? (1)? (2)? (3)?
Control Group:
Test Group:
Show:
Dishabituated to DA, THA, not BA
Dishabituated only to BA
Again show infants are show the Classic McGurk Effect
Audio BA, Visual GA  DA
Caveat: DA ≈THA

40. Coarticulation Revisited
Motor Theory vs. Auditory Theory Question 3
Coarticulation
Coarticulation Revisited
Frequency (Hz)
Time (msec)

41. Coarticulation Revisited
Motor Theory vs. Auditory Theory Question 3
Coarticulation
Coarticulation Revisited

42. Coarticulation Revisited
Motor Theory vs. Auditory Theory Question 3
Coarticulation
Coarticulation Revisited

43. Coarticulation Revisited
Motor Theory vs. Auditory Theory Question 3
Coarticulation
Coarticulation Revisited
[šu] shoe, [ša] shot
[u] oo F1: 310 F2: 870
[a] ah F1: 710 F2: 1100
[š] has lower frication frequency with [u]
[š] has higher frication frequency with [a]

44. Coarticulation & Identification Curve
Motor Theory vs. Auditory Theory Question 3
Coarticulation
Coarticulation & Identification Curve
What should the identification curve if there is categorical perception?

45. Coarticulation & Identification Curve
Motor Theory vs. Auditory Theory Question 3
Coarticulation
Coarticulation & Identification Curve
Contextual Effect? (consonant plus vowel)
[u]
[a]
We know:
[š] lo freq w/ [u]
[š] hi freq w/ [a]

46. Coarticulation & Identification Curve
Motor Theory vs. Auditory Theory Question 3
Coarticulation
Coarticulation & Identification Curve
Contextual Effect? (consonant plus vowel)
[u]
[a]
We know:
[š] lo freq w/ [u]
[š] hi freq w/ [a]

47. Motor vs. Auditory Theory Score card
Motor Theory vs. Auditory Theory Question 3
Motor vs. Auditory Theory Score card
Q3: Is Speech Perception based on our knowledge of articulation
Answer: YES. Our compensation for Coarticulation Effects and response to McGurk Stimuli suggest that knowledge of articulation influences speech perception.
Predicted by Motor Theory
Innate connection btw production and perception
Inconsistent with Auditory Theory
Though perhaps perceptual learning might explain these effects

48. Provisional Conclusions
Motor Theory vs. Auditory Theory General Conclusions
Provisional Conclusions
Speech Perception makes use of some auditory mechanisms which evolved prior to language
These abilities are innate
Speech Perception also makes use of our knowledge of articulation
– These abilities are likely innate

49. Becoming a Native Listener
Language Specific Fine Tuning
Becoming a Native Listener
Languages differ in their inventories of phonemes.
What develops or changes in our speech perception abilities?

50. Japanese vs. English (Miyawaki et al. 1975)
Language Specific Fine Tuning
Japanese vs. English (Miyawaki et al. 1975) RA
AMERICANS LA

51. unvoiced unaspirated retroflex vs. dental stop
Language Specific Fine Tuning
Hindi
(spoken in India)
unvoiced unaspirated retroflex vs. dental stop
Dental Stop – tip of tongue touching
back of front teeth
Retroflex Stop – tongue curled so tip is
behind alveolar ridge
(English /t/ is typically somewhere between the two)

52. Can you hear the difference?
Language Specific Fine Tuning
Can you hear the difference?
dental
Hindi
retroflex

53. Salish glotalized voiceless stops (Native North American language):
Language Specific Fine Tuning
Salish
(Native North American language):
glotalized voiceless stops
Uvular – tongue is raised against the velum
Velar – tongue is raised behind the velum
(they are actually ejectives - ejective is produced by obstructing the airflow by raising the back of the tongue against or behind the velum)

54. When does changes in sensitivity occur?
Language Specific Fine Tuning
When does changes in sensitivity occur?
Infancy
Adulthood
… And testing method?

55. Conditioned Head-Turn
Language Specific Fine Tuning
Conditioned Head-Turn
Conditioning
Child hears a string of sounds.
Conditioned to turn head when detects a change (e.g., bell  whistle) with reward
Test
Speech sounds (e.g., da, da, da, da, ta,…)
Does the child turn his or her head with changed from da to ta?
Werker:
Kuhl:

56. When does Change Occur? Language Specific Fine Tuning 6-8m 8-10m

57. What is changing? Two contrasting views: 1 or 2?
Language Specific Fine Tuning
What is changing? Two contrasting views: 1 or 2?
Maintenance or Loss
If you don’t use it, you lose it.
Parallel aspects of early visual development.
Functional Reorganization
Existing architecture reorganized for higher level of processing.

58. What is changing? Two contrasting views
Language Specific Fine Tuning
What is changing? Two contrasting views

59. What is changing? 1. Maintenance or Loss View
Language Specific Fine Tuning
What is changing? 1. Maintenance or Loss View
Phonology
Phonetics
Structure-changing
Non-native boundaries
disappear.
Resulting in native language phonetics
Acoustics

60. What is changing? 2. Functional Reorganization
Language Specific Fine Tuning
What is changing? 2. Functional Reorganization
Phonology
Phonetics
Structure-building
Native language
phonemes
built from
universal phones
Acoustics

61. Language Specific Fine Tuning
Which view?
Werker (1997) noted some problems for the maintenance or loss view.
1. Many of the uncategorized sounds do appear in the native language but just are not meaningful (e.g., as allophones), and speakers can be made aware of the difference.
Example:
/p/ is only aspirated in “pin” and not “spin’
/p/ in “pin” and “spin” are allophones in English
But could be minimal pairs in some other languages.

62. Language Specific Fine Tuning
Which view?
Werker (1997) noted some problems for the maintenance or loss view.
1. Many of the uncategorized sounds do appear in the native language but just are not meaningful (e.g., as allophones), and speakers can be made aware of the difference.
2. Children who fail to show categorical perception for non-native phonemes can acquire a new language without an accent.
3. Adults can be trained to make non-native distinctions.
4. Perceptual distinction is readily available for non-linguistic tasks.

63. Language Specific Fine Tuning
Which model?
Werker (1997): The evidence that poses problems for maintenance or loss view supports the functional reorganization view.
I.e., the view that:
Those perceptual categories which are meaningful in the native language become speech categories.
The remainder are perceived but not recruited in speech perception.

64. Why functional reorganization?
Language Specific Fine Tuning
Why functional reorganization?
Developmentally: months-olds lose non-native distinctions
What is going on?
Analyzing statistical regularities in the input language and working towards word learning?
(more to come when we study language acquisition)

65. Innate components Auditory abilities Articulatory rudiments
Language Specific Fine Tuning
Innate components
Auditory
Auditory abilities
Categorical Perception
Articulatory rudiments
Infants babble
Phonetics serves as a connection
McGurk effect
Phonetics
Articulatory
innate

66. Constructing phonology
Language Specific Fine Tuning
Constructing phonology
Syntactic
Lexical
Phonological
constructed
Auditory
Phonetics
Articulatory
innate