Patterns of development in stop-release cues to coda contrasts in American-English-speaking 2-year-olds.

Abstract

A distinctive characteristic of early speech is “exaggerated” release of stop consonants including multiple bursts and heavy post-release noise [Imbrie (2005)]. This study provides an in-depth investigation of changes in the acoustic characteristics of stop coda release from 1;6 to 2;6 years, focusing on their interaction with emerging linguistic contrasts. We examined how various non-spectral coda-release-related cues, such as the presence and duration of post-release noise, varied with coda voicing and place (alveolar versus velar) in spontaneous speech from six American-English-speaking mother-child dyads. Starting as early as 1;6, children produced many of the same types of correlates of voicing and place as adults did, but they exhibited more frequent occurrences and longer durations of these cues compared to mothers; this exaggeration decreased by 2;6. In utterance-medial position, where the decrease was particularly striking, it occurred in a selective, stepwise fashion rather than simultaneously in all contexts. That is, the decrease was larger for voiceless codas than for voiced codas, and for place contrasts, the values decreased first for velars, and only later for alveolars. This observation raises the question of whether such selective fine-tuning is characteristic of phonological development across languages, and if so, what the underlying mechanisms might be. [Work supported by NIH R01HD057606.]