Short-term release cues to stop-consonant place of articulation in child speech

In recent work Blumstein and Stevens (J. Acoust. Soc. Am. 66, 1001-1017 (19179); 67, 648-662 (1980) have proposed that the short-term onset spectra at stop-consonant releases provide invariant cues for the perception of place of articulation, and that the salient acoustic characteristics of these cues can be characterized by a set of templates. The present study investigated the suitability of these templates for characterizing place of articulation in utterance-initial voiced stop consonants produced by two children 71-75 weeks old in spontaneous discourse. The overall correct categorization rate for the templates was 65%, with 70% correct categorizations for the bilabial template, 85% for the alveolar template, and 40% for the velar template. The results of a perceptual study in which listeners were asked to identify place of articulation for computer-edited 15-, 25-, 40-, and 135-ms samples of the initial parts of these utterances were compared with the results of the template matching study. Although listeners' identification of place of articulation was at well above chance level on even the 15-ms tokens, there was no correlation between the results of the template-matching study and the perceptual data. The perceptual data thus indicate that short-term onset cues exist in the spontaneous speech of children at an early stage of language development, however, these cues do not appear to be adequately characterized by the Blumstein-Stevens templates.