JLP315H1 Lecture Notes - Lecture 4: Chief Operating Officer, Vocal Tract, Speech Perception
Document Summary
0-6 weeks: reflexive vocalizations: crying, fussing. 0-2 months: phonation, quasivowels and glottals: vocal cords moving, quasivowels not recognizable. 4-5 months: expansion stage: full vowels, raspberries, marginal babbling. 31-50 weeks: reduplicated babbling: series of consonant and vowel-like elements. 6+ months: canonical stage: well-formed canonical syllables, reduplicated sequences (e. g. , babababa ) While speech perception is apparent from birth, speech production starts around 6 months of age: making noises that sounds somewhat like speech. Between 6-8 months: babbling: manual: rudimentary version of sign language, lacks fluidity of adult sign language, vocal: rudimentary version of verbal speech. Identical timing suggests this is due to maturation of the neural substrate supporting language: not doing it early = not cognitively capable yet. Birth to 4 months: infant"s vocal tract is similar to that of apes. Babbling can only occur once the configuration of the vocal tract is ready for it.
