Age-related differences in the organization of articulatory gestures for /schwa/♯ stop–vowel sequences.

Abstract

Acoustic analyses were performed on /schwa/♯ stop–vowel samples from adults and from children (3, 5, and 7 years of age). Stops were {t k d} and vowels were {i ɑ u}. Temporal measures indicated that, compared to adults: (1) children’s /schwa/’s were generally longer and length was more affected by the voicing of the following stop; (2) children’s closure durations were longer; and (3) acoustic voice onset times for 5- and 7-year-olds’ samples were similar to those of adults, but 3-year-olds’ /t/’s were shorter. Measures of formant frequency indicated that: (1) children’s F1’s were similar to those of adults through the entire utterance; (2) children’s F2’s in the stop aspiration noise and at vowel onset showed greater effects of the upcoming vowel than adults; and (3) children’s F2’s at vowel onset showed greater effects of place of closure for the previous stop. Taken together, these results suggest that the organization of articulatory gestures for children between 3 and 7 years of age does not yet show mature phonologic structure. [Work supported by NIH Grant DC-00633.]