VOT in the babbling of French- and English-learning infants.

Different languages use voice onset time (VOT) in different ways to signal the voicing contrast, for example, short lag/long lag (English) vs. prevoiced/short lag (French). Also, VOT depends on place of articulation, with labial VOTs being shorter than velar and alveolar and, sometimes, alveolar being shorter than velar. Here we examine the VOT in babbled utterances of five French-learning and five English-learning infants at ages 9 and 12 months. There was little or no difference between the languages for duration of positive VOTs, which were usually in the "short lag" range. The duration of prevoicing also did not differ between languages, but the proportion of prevoiced utterances did (French-learning infants: 44.2% prevoicing; English-learning: 14.3%). Labial, alveolar and velar stops differed in VOT, with alveolar longer than labial and velar longer than alveolar, suggesting a mechanical cause. The lack of long-lag VOT indicates that the English-learning infants have not mastered aspiration by 12 months. The different proportions of prevoicing, however, suggest that the French-learning infants attempt to imitate the prevoicing that is used frequently (and contrastively) in their native language environment. The results suggest that infants are sensitive to the voicing categories of the ambient language but that they may be able to control prevoicing more successfully than aspiration.