A speech recognition strategy based on making acoustic evidence and phonetic knowledge explicit

We describe a prototype implementation of a representational approach to acoustic-phonetics in knowledge-based speech recognition. Our scheme is based on the 'Speech Sketch', a structure which enables acoustic evidence and phonetic knowledge to be represented in similar ways, so that like can be compared with like. The process of building the Speech Sketch begins with spectrogram image processing and goes on to exploit elementary phonetic constraints. A multiscale approach is used throughout. The process of interpreting the Speech Sketch makes use of an object-oriented phonetic knowledge base. Objects in the knowledge base can be matched against objects in the Speech Sketch in a manner directed by the incoming evidence. This technique promises to avoid a combinatorial explosion

Acoustic-phonetic decoding of speech : problems and solutions

Acoustic phonetic decoding of speech recognition constitutes a major step in the process of continuous speech recognition . This paper reminds the difficulties of the problem together with the main methods proposed so far in order to solve it . We then concentrate on the différent complementary approaches Chat have been investigated by our group : expert system based on spectrogram reading, recognition by phonetic triphones, connectionist model based on the cortical column unit and stochastic recognition without segmentation .Le décodage acoustico-phonétique constitue une étape importante en reconnaissance de la parole continue . Cet article rappelle d'abord les difficultés du problème et les principales méthodes qui ont été proposées pour le résoudre . Il présente ensuite les diverses approches complémentaires adoptées par notre équipe : système expert fondé sur l'activité de lecture de spectrogrammes, reconnaissance par triplets phonétiques, modèle connexionniste de colonne corticale et reconnaissance par méthode stochastique sans segmentation