Syntax-based speech recognition: how a syntactic parser can help a recognition system

This contribution is a report on an on-going research aiming at the development of a speech recognition system for French, combining a standard HMM recognition tool with a syntactic parser. Because of the very high number of homophones in French and because several agreement rules spread over an unbounded number of words, we designed our GB-based morphological and syntactic parser to output a correct orthographic form from a lattice of phonemes produced by the front-head HMM recognition system. This resulting lattice of phonemes is processed by the syntactic parser, which selects the best word sequence according to its linguistic knowledge. The originality of this approach is the use of a syntactic parser, tuned to phonetic inputs, for a speech recognition task.