2. 3308 First Language acquisition Acquisition of sounds Perception Sook Whan Cho Fall, 2012

3. 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?

4. 운율의 표기

5. 운율이 단조롭다면 …

6. 운율이 없다면 …

7. “What did you say before that?” 합성 이전

8. “What did you say before that?” 합성 이후

9. 합성 이전 합성 이후 Korean example

10. Prosody 운율 기본주파수 (fundamental frequency) 길이 (duration) 강도 (intensity)

11. 기본주파수 (fundamental frequency) Vibrations of vocal cords measured 성대의 진동수 ( 단위 : Hz) Intonation Pitch Stress Tone

12. 길이 duration consonants/vowels/sentences Measured by 1/1000 seconds ( 단위 : msec) 성대진동 개시구간 (voice onset time, VOT) 강세 (stress)

13. 강도 intensity Stress marking on consonants/vowels Measured by dB (decibel) English words with a stressed vowel

14. Categorical perception We (= adults) perceive speech sounds as categories. Physically continuous acoustic differences are perceived as distinct groups of sounds. Category A Category B

15. Voice onset time (VOT) and voicing 60 msec

16. 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. % identified as /d/ % discriminated VOTVOT difference 0ms 20ms 40ms 20ms 40ms 60ms D D T D T T

17. 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. % identified as /d/ % discriminated VOTVOT difference 0ms 20ms 40ms 20ms 40ms 60ms D D T D T T

18. Infants’ categorical perception of VOT 1-, 4-mos reaction to changes in VOT High-amplitude sucking procedure (Eimas et al, 1971) No change 40 ↔ 60ms20 ↔ 40ms