Vowel durations in the conversational speech of children

Previous data on segment durations produced by children have been based on imitated speech samples or repeated nonsense syllables [e.g., F. G. DiSimoni, J. Acoust. Soc. Am. 55, 362–363 (1974); B. L. Smith, J. Phon. 6, 37–68 (1978)]. One result of this research seems to be that children in the three-to-six-year old range have vowel durations which are substantially longer than corresponding vowel durations in adult speech. We considered the possibility that the vowel durations observed in previous studies of child speech are conditioned in part by task variables. For example, if children imitate a live-voice model [Smith, op. cit.], that model may contain vowel durations which are appropriate to adult-child speech and therefore longer than the kinds of vowel durations reported in the literature for adults. The present study reports vowel durations from the spontaneous speech of one three-year old female and one five-year old male. Results include observations concerning vowel duration variability and context effects.