Acoustic cues to the voicing contrast in coda stops in the speech of 2-year-olds learning American English

Abstract

Developing a model of how children acquire the phonological feature contrasts and phonetic cues of their adult speech community requires a detailed understanding of how production changes during development. Earlier studies based on listening provided an initial estimate of these patterns; recent instrumental studies of the acoustic and articulatory details of production during development have revealed some surprises, including covert contrasts between distinctive feature categories (e.g., Scobbie et al., 1996) and of incomplete acquisition of adult feature-cue patterns (Imbrie, 2005), which can be difficult for adults to hear. Few instrumental studies, however, have focused on the child's cue patterns for coda consonants (although see Song and Demuth, in press). Our study of cues to the feature [voice] for coda stops used quantitative acoustic analyses of tokens from the Imbrie corpus of 2-year-old speech to compare child productions with those of their adult caretakers. Results show that a) many children produce a noisy region at the end of the vowel for voiceless codas (in duck, cup) but a long strong voice bar during closure for voiced codas (in bug, tub), and b) these cues may be exaggerated versions of the feature cues of their adult caretakers.