Phonetic triplets in acoustic-phonetic decoding of continuous speech

A knowledge-based approach which stores knowledge in the form of contextual prototypes called triplets is presented. A triplet consists of an acoustic description using acoustic events (burst features, formant trajectories, etc.) and a component representing the acoustic correlates used by a human expert. Attention is given to vowel and plosive centered triplets and the corresponding matching algorithm relying on the acoustic description. Representing knowledge in the form of prototypes allows the recognition system to compare reference triplets to each other. The same acoustic comparisons can be made between triplet instances. It is shown how a relaxation algorithm using this type of acoustic comparison (which can be viewed as constraints) allows the system to increase the consistency of global triplet labeling for the sentence to be decoded