CRIN-CNRS & INRIA Lorraine, BP 239, 54506 Vand(oe ligature)uvre-les-Nancy Cedex, France
A perceptual and acoustic investigation was conducted to better understand the discrimination power of the burst regarding place-of-articulation of French stops. These perceptual experiments showed that the burst provided very reliable spectral information about stop place and that prior knowledge of the vowel identity led to a slight but significant improvement in stop identification [A. Bonneau et al., to appear in J. Acoust. Soc. Am. (1995)]. This acoustic study confirmed that burst cues cannot be extracted and exploited without taking into account the vocalic context. Based on these conclusions, a hybrid recognizer was implemented. First, it recognizes the vocalic context, and then it takes this into account to extract and exploit the burst cues for the stop recognition task. The vocalic context was correctly recognized in 90% of the cases: Back vowels were perfectly recognized, central vowels with 80% accuracy, rounded front vowels with 90%, and unrounded front vowels with 89%. The global recognition rate of stop place was 88%. Statistical tests indicated that the best recognized stop was /k/ (93%), then /t/ (87%), and /p/ (84%). These results agree with listeners' performance observed in the perceptual experiments (/k/: 94%> /t/: 91% > /p/: 62%).