Acoustic cues to stop coda voicing contrasts in 1 to 2-year-olds’ American English.

Abstract

One limitation in understanding the mechanisms underlying children’s variable productions has been the reliance on perception-based segmental transcription. This raises the possibility that children may make covert, acoustic distinctions that are not perceived by the transcriber. Shattuck-Hufnagel et al. [S. Shattuck-Hufnagel, K. Demuth, H. Hanson & S. Stevens, submitted] investigated this issue employing Stevens’ [K. N. Stevens, J. Acoust. Soc. Am. 111, 1872–1891 (2002)] feature-based acoustic model of perception/production. They found that 2,6–3,6-year-olds exhibited systematic acoustic cues to coda voicing contrasts (e.g., dog versus duck): voice-bar was more likely to precede voiced codas, whereas vowel glottalization was more likely to precede voiceless codas. The present study extended this investigation to velar codas in three 1,6–2,6-year-olds and their mothers, showing similar results: both exhibited more use of voice-bar before voiced compared to voiceless codas. For mothers, the duration of voice-bar was also longer for voiced codas, and children showed a trend in this direction. However, only mothers showed a significantly higher use of vowel glottalization before voiceless codas. Thus, although younger children also produce some acoustic cues to voicing distinctions, others take time to become adultlike. Physiological and environmental factors are discussed to explain these results. [Work supported by R01 HD057606.]