Selective acoustic cues for French voiceless stop consonants

The objective of this study is to define selective cues that identify only certain realizations of a feature, more precisely the place of articulation of French unvoiced stops, but have every realization identified with a very high level of confidence. The method is based on the delimitation of "distinctive regions" for well chosen acoustic criteria, which contains some exemplars of a feature and (almost) no other exemplar of any other feature in competition. Selective cues, which correspond to distinctive regions, must not be combined with less reliable acoustic cues and their evaluation should be done on reliable elementary acoustic detector outputs. A set of selective cues has been defined for the identification of the place of /p,t,k/, and then tested on a corpus of sentences. The cues were estimated from formant transitions and the transient segment (an automatic segmentation of the transient part of the burst has been designed). About 38% of the feature realizations have been identified by selective cues on the basis of their very distinctive patterns. The error rate, which constitutes the crucial test of our approach, was 0.7%. This opens the way to interesting applications for the improvement of oral comprehension, lexical access, or automatic speech recognition.