3308 first language acquisition acquisition of sounds perception sook whan cho fall, 2012
TRANSCRIPT
3308First Language acquisition
Acquisition of sounds
Perception
Sook Whan Cho
Fall, 2012
Questions onacquisition of sounds
- How do newborns perceive speech sounds?
- When and how do infants learn meaningful sound differences (phonemic contrasts) of the native language?
- When do infants learn sound combinations (phonotactics) of the native language?
- When and how do infants learn to pick out words from a speech stream?
운율의 표기
운율이 단조롭다면…
운율이 없다면…
“What did you say before that?”
합성 이전
“What did you say before that?”
합성 이후
합성 이전
합성 이후
Korean example
Prosody 운율
• 기본주파수 (fundamental frequency)
• 길이 (duration)
• 강도 (intensity)
기본주파수 (fundamental frequency)
Vibrations of vocal cords measured성대의 진동수 ( 단위 : Hz)
IntonationPitchStressTone
길이 duration
consonants/vowels/sentences
Measured by 1/1000 seconds ( 단위 : msec)
• 성대진동 개시구간 (voice onset time, VOT)
• 강세 (stress)
강도 intensity
Stress marking on consonants/vowels
Measured by dB (decibel)
English words with a stressed vowel
Categorical perception
We (= adults) perceive speech sounds as categories. Physically continuous acoustic differences are perceived as distinct groups of sounds.
Category A Category B
Voice onset time (VOT) and voicing
60 msec
Categorical perception of VOT
0
20
40
60
80
100
0 10 20 30 40 50 60
A VOT continuum is perceived as if it contains distincts sets of sounds. We hear the difference only around the boundary.
% id
entif
ied
as /d
/
0
20
40
60
80
100
0-20 10-30 20-40 30-50 40-60
% d
iscr
imin
ated
VOT VOT difference
0ms
20ms
40ms
20ms
40ms
60ms
D
D
T
D
T
T
Categorical perception of VOT
0
20
40
60
80
100
0 10 20 30 40 50 60
A VOT continuum is perceived as if it contains distincts sets of sounds. We hear the difference only around the boundary.
% id
entif
ied
as /d
/
0
20
40
60
80
100
0-20 10-30 20-40 30-50 40-60
% d
iscr
imin
ated
VOT VOT difference
0ms
20ms
40ms
20ms
40ms
60ms
D
D
T
D
T
T
Infants’ categorical perception of VOT
1-, 4-mos reaction to changes in VOT
High-amplitude sucking procedure
(Eimas et al, 1971)
No change40 ↔ 60ms20 ↔ 40ms