3308
First Language acquisition
Acquisition of sounds
Perception
Sook Whan Cho
Fall, 2012
Questions on
acquisition 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
Korean example
합성 이전
합성 이후
Prosody 운율
• 기본주파수 (fundamental frequency)
• 길이 (duration)
• 강도 (intensity)
기본주파수
(fundamental frequency)
Vibrations of vocal cords measured
성대의 진동수 (단위: Hz)
Intonation
Pitch
Stress
Tone
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
A VOT continuum is
perceived as if it
contains distincts sets
of sounds. We hear the
difference only around
the boundary.
D
0ms
20ms
D
D
20ms
40ms
T
T
40ms
60ms
T
100
% discriminated
% identified as /d/
100
80
60
40
20
0
0
10
20
30
VOT
40
50
60
80
60
40
20
0
0-20
10-30
20-40
30-50
VOT difference
40-60
Categorical perception of VOT
A VOT continuum is
perceived as if it
contains distincts sets
of sounds. We hear the
difference only around
the boundary.
D
0ms
20ms
D
D
20ms
40ms
T
T
40ms
60ms
T
100
% discriminated
% identified as /d/
100
80
60
40
20
0
0
10
20
30
VOT
40
50
60
80
60
40
20
0
0-20
10-30
20-40
30-50
VOT difference
40-60
Infants’ categorical perception of VOT
High-amplitude
sucking procedure
20 ↔ 40ms
40 ↔ 60ms
No change
1-, 4-mos reaction to changes in VOT
(Eimas et al, 1971)