2. Acoustic Continua and Phonetic Categories

3. Frequency - Tones

7. Frequency - Complex Sounds

9. Frequency - Vowels Vowels combine acoustic energy at a number of different frequencies Different vowels ([a], [i], [u] etc.) contain acoustic energy at different frequencies Listeners must perform a ‘frequency analysis’ of vowels in order to identify them (Fourier Analysis)

10. Joseph Fourier (1768-1830) Time --> Frequency Amplitude Any function can be decomposed in terms of sinusoidal (= sine wave) functions (‘basis functions’) of different frequencies that can be recombined to obtain the original function. [Wikipedia entry on Fourier Analysis]

11. Frequency - Male Vowels

13. Frequency - Female Vowels

15. Synthesized Speech Allows for precise control of sounds Valuable tool for investigating perception

16. Timing - Voicing

17. Voice Onset Time (VOT) 60 msec

18. English VOT production Not uniform 2 categories

19. Perceiving VOT ‘Categorical Perception’

20. Discrimination Same/Different

21. Discrimination Same/Different 0ms 60ms

22. Discrimination Same/Different 0ms 60ms Same/Different

23. Discrimination Same/Different 0ms 60ms Same/Different 0ms 10ms

24. Discrimination Same/Different 0ms 60ms Same/Different 0ms 10ms Same/Different

25. Discrimination Same/Different 0ms 60ms Same/Different 0ms 10ms Same/Different 40ms

26. Discrimination Same/Different 0ms 60ms Same/Different 0ms 10ms Same/Different 40ms Why is this pair difficult?

27. Discrimination Same/Different 0ms 60ms Same/Different 0ms 10ms Same/Different 40ms Why is this pair difficult? (i) Acoustically similar? (ii) Same Category?

28. Discrimination Same/Different 0ms 60ms Same/Different 0ms 10ms Same/Different 40ms Why is this pair difficult? (i) Acoustically similar? (ii) Same Category? A More Systematic Test

29. Discrimination Same/Different 0ms 60ms Same/Different 0ms 10ms Same/Different 40ms A More Systematic Test 0ms 20ms 40ms 20ms 40ms 60ms

30. Discrimination Same/Different 0ms 60ms Same/Different 0ms 10ms Same/Different 40ms A More Systematic Test 0ms 20ms 40ms 20ms 40ms 60ms DT D T T D Within-Category Discrimination is Hard

31. Cross-language Differences R L

32. R L R L

33. Cross-Language Differences English vs. Japanese R-L

34. Cross-Language Differences English vs. Hindi alveolar [d] retroflex [D] ?

35. Russian -40ms -30ms -20ms -10ms 0ms 10ms

36. Kazanina et al., 2006 Proceedings of the National Academy of Sciences, 103, 11381-6

38. Discrimination Same/Different 0ms 60ms Same/Different 0ms 10ms Same/Different 40ms A More Systematic Test 0ms 20ms 40ms 20ms 40ms 60ms DT D T T D Within-Category Discrimination is Hard

39. Quantifying Sensitivity

40. Response bias Two measures of discrimination –Accuracy: how often is the judge correct? –Sensitivity: how well does the judge distinguish the categories? Quantifying sensitivity –HitsMisses False AlarmsCorrect Rejections –Compare p(H) against p(FA)

41. Quantifying Sensitivity Is one of these more impressive? –p(H) = 0.75, p(FA) = 0.25 –p(H) = 0.99, p(FA) = 0.49 A measure that amplifies small percentage differences at extremes z-scores

42. Normal Distribution Mean (µ) Dispersion around mean Standard Deviation A measure of dispersion around the mean. √( ) ∑(x - µ) 2 n Carl Friederich Gauss (1777-1855)

43. The Empirical Rule 1 s.d. from mean: 68% of data 2 s.d. from mean: 95% of data 3 s.d. from mean: 99.7% of data

44. Normal Distribution Mean (µ) 65.5 inches Standard deviation  = 2.5 inches Heights of American Females, aged 18-24

45. Quantifying Sensitivity A z-score is a reexpression of a data point in units of standard deviations. (Sometimes also known as standard score) In z-score data, µ = 0,  = 1 Sensitivity score d’ = z(H) - z(FA)

46. See Excel worksheet sensitivity.xls

47. Quantifying Differences

48. (Näätänen et al. 1997) (Aoshima et al. 2004) (Maye et al. 2002)

49. Normal Distribution Mean (µ) Dispersion around mean Standard Deviation A measure of dispersion around the mean. √( ) ∑(x - µ) 2 n

50. The Empirical Rule 1 s.d. from mean: 68% of data 2 s.d. from mean: 95% of data 3 s.d. from mean: 99.7% of data

51. If we observe 1 individual, how likely is it that his score is at least 2 s.d. from the mean? Put differently, if we observe somebody whose score is 2 s.d. or more from the population mean, how likely is it that the person is drawn from that population?

52. If we observe 2 people, how likely is it that they both fall 2 s.d. or more from the mean? …and if we observe 10 people, how likely is it that their mean score is 2 s.d. from the group mean? If we do find such a group, they’re probably from a different population

53. Standard Error is the Standard Deviation of sample means.

54. If we observe a group whose mean differs from the population mean by 2 s.e., how likely is it that this group was drawn from the same population?

56. Development of Speech Perception in Infancy

57. Voice Onset Time (VOT) 60 msec

58. Perceiving VOT ‘Categorical Perception’

59. Discrimination Same/Different 0ms 60ms Same/Different 0ms 10ms Same/Different 40ms A More Systematic Test 0ms 20ms 40ms 20ms 40ms 60ms DT D T T D Within-Category Discrimination is Hard

60. Abstraction Representations –Sound encodings - clearly non-symbolic, but otherwise unclear –Phonetic categories –Memorized symbols: /k/ /æ/ /t/ Behaviors –Successful discrimination –Unsuccessful discrimination –‘Step-like’ identification functions –Grouping different sounds

61. Let’s Learn Inuktitut! Video: Nunavik: Building on the Knowledge of Ancestors

62. Vowels Consonants

63. Three Classics

64. Development of Speech Perception Unusually well described in past 30 years Learning theories exist, and can be tested… Jakobson’s suggestion: children add feature contrasts to their phonological inventory during development Roman Jakobson, 1896-1982 Kindersprache, Aphasie und allgemeine Lautgesetze, 1941

65. Developmental Differentiation 0 months 6 months12 months18 months Universal Phonetics Native Lg. Phonetics Native Lg. Phonology

66. #1 - Infant Categorical Perception Eimas, Siqueland, Jusczyk & Vigorito, 1971

67. Discrimination Same/Different 0ms 60ms Same/Different 0ms 10ms Same/Different 40ms A More Systematic Test 0ms 20ms 40ms 20ms 40ms 60ms DT D T T D Within-Category Discrimination is Hard

68. high amplitude sucking non-nutritive sucking

69. English VOT Perception To Test 2-month olds High Amplitude Sucking Eimas et al. 1971

70. General Infant Abilities Infants’ show Categorical Perception of speech sounds - at 2 months and earlier Discriminate a wide range of speech contrasts (voicing, place, manner, etc.) Discriminate Non-Native speech contrasts e.g., Japanese babies discriminate r-l e.g., Canadian babies discriminate d-D [these findings based mostly on looking/headturn studies w/ 6 month olds]

71. Universal Listeners Infants may be able to discriminate all speech contrasts from the languages of the world!

72. How can they do this? Innate speech-processing capacity? General properties of auditory system?

73. What About Non-Humans? Chinchillas show categorical perception of voicing contrasts! PK Kuhl & JD Miller, Science, 190, 69-72 (1975)

74. Joan Sinnott, U. of S. Alabama More recent findings… 1.Auditory perceptual abilities in macaque monkeys and humans differ in various ways 2.Discrimination sensitivity for b-p continua is more fine-grained in (adult) humans (Sinnott & Adams, JASA, 1987) 3.Sensitivity to cues to r-l distinctions is different, although trading relations are observed in humans and macaques alike (Sinnott & Brown, JASA, 1997) 4.Some differences in vowel sensitivity… Suitability of Animal Models

75. #2 - Becoming a Native Listener Werker & Tees, 1984

76. When does Change Occur? About 10 months Janet Werker U. of British Columbia Conditioned Headturn Procedure

77. When does Change Occur? Hindi and Salish contrasts tested on English kids Janet Werker U. of British Columbia Conditioned Headturn Procedure

78. What do Werker’s results show? Is this the beginning of efficient memory representations (phonological categories)? Are the infants learning words? Or something else?

79. Korean has [l] & [r] [rupi] “ruby” [kiri] “road” [saram] “person” [irumi] “name” [ratio] “radio” [mul] “water” [pal] “big” [s\ul] “Seoul” [ilkop] “seven” [ipalsa] “barber”

80. #3 - What, no minimal pairs? Stager & Werker, 1997

81. A Learning Theory… How do we find out the contrastive phonemes of a language? Minimal Pairs

83. Word Learning Stager & Werker 1997 ‘bih’ vs. ‘dih’ and ‘lif’ vs. ‘neem’

85. PRETEST

86. HABITUATION TEST SAMESWITCH

87. Word learning results Exp 2 vs 4

88. Why Yearlings Fail on Minimal Pairs They fail specifically when the task requires word-learning They do know the sounds But they fail to use the detail needed for minimal pairs to store words in memory !!??

89. One-Year Olds Again One-year olds know the surface sound patterns of the language One-year olds do not yet know which sounds are used contrastively in the language… …and which sounds simply reflect allophonic variation One-year olds need to learn contrasts

90. Maybe not so bad after all... Children learn the feature contrasts of their language Children may learn gradually, adding features over the course of development Phonetic knowledge does not entail phonological knowledge Roman Jakobson, 1896-1982

91. Werker et al. 2002 141720 14 months17 months20 months 0 60300600

93. Swingley & Aslin, 2002 14-month olds did recognize mispronunciations of familiar words Dan Swingley, UPenn

94. Alternatives to Reviving Jakobson Word-learning is very hard for younger children, so detail is initially missed when they first learn words Many exposures are needed to learn detailed word forms at early stages of word-learning Success on the Werker/Stager task seems to be related to the vocabulary spurt, rapid growth in vocabulary after ~50 words

95. (Dietrich, Swingley, & Werker 2007)

96. Exp 1: tam - ta:m Exp 2: tæm - tæ:m Exp 3: ta/æm - tem Length factor ~1.8-2.0

97. (Dietrich, Swingley, & Werker 2007)

98. Questions about Development

99. 6-12 Months: What Changes?

100. Structure Changing Patricia Kuhl U. of Washington

101. Structure Adding Evidence for Structure Adding (i) Some discrimination retained when sounds presented close together (e.g. Hindi d-D contrast) (ii) Discrimination abilities better when people hear sounds as non-speech (iii) Adults do better than 1-year olds on some sound contrasts Evidence for Structure Changing (i) No evidence of preserved non-native category boundaries in vowel perception

102. Sources of Evidence Structure-changing: mostly from vowels Structure-adding: mostly from consonants Conjecture: structure-adding is correct in domains where there are natural articulatory (or acoustic) boundaries [cf. Phillips 2001, Cogn. Sci., 25, 711-731]

103. So how do infants learn…?

105. Slides: Swingley 2006, ICIS

108. [2003, Proceedings of the National Academy of Sciences] 5 hours’ exposure to Mandarin ± human interaction

110. fricativeaffricate Alveo-palatals

113. Jessica Maye, Northwestern U.

116. Infants at age 6-8 months are still ‘universal listeners’, cf. Pegg & Werker (1997) Infants trained on bi-modal distribution show ‘novelty preference’ for test sequence with fully alternating sequence How could the proposal scale up?

122. p(a) = p(b) p(a) = 2 x p(b)

123. 1.0.5.25.1

126. Slides: Swingley 2006, ICIS

129. Fenson et al. 2000

130. bird dog duck doll bread candy head dish radio outside feed today dark toast hat ants tooth table television blanket outside plant wait today fast hurt soft out stroller kitty water babysitter pretty patty cake bottle kitchen don’t night (night) MacArthur Short CDI - 89 items

131. Fei Xu, UBC

132. Xu & Carey 1996 10 mo.: no surprise 12 mo.: surprise --> “10 month olds do not represent basic sortal/kind concepts” Xu 2002 Add words! 9 mo.:

134. Fulkerson & Waxman 2007 12 months6 months Words µ =.59, p =.007µ =.63, p <.001 Tonesµ =.53, p =.2µ =.54, p =.2

135. Yeung & Werker 2008 Effect of Type (±alternating) Exp1: F(1,18) = 5.74, p <.05 Exp2: F(1,18) = 0.53, p =.47 Naturally produced Hindi syllables Dental vs. retroflex A.Familiarize sound-object links B.Test sound discrimination only Exp1: consistent links Exp2: inconsistent links