LARGE-VOCABULARY SPEECH RECOGNITION SYSTEM

摘要

PROBLEM TO BE SOLVED: To obtain the large-vocabulary speech recognition system which can perform real-time operation with inexpensive hardware constitution even for a very large vocabulary by composing a parser of a forward and a backward operation part and making a viterbi search driven under restriction conditions of tri-phoneme units considering phoneme environment. ;SOLUTION: This system is equipped with the parser 5 including the forward operation part 6 and backward operation part 7. The forward operation part 6 makes a viterbi search under restriction conditions of phoneme units considering the phoneme environment and the backward operation part 7 develops a hypothesis by using a viterbi search while referring to a tree structure dictionary of language models 10 considering the phoneme environment. Then the order of development is determined on a best.first basis by using A* algorithm making good use of the sum of the score of the forward operation result and the score of the operation result of the backward viterbi search made in phoneme units, and outputted as a word candidate for a recognition result in the order of received hypotheses and once a specific number of word candidates are found, the backward operation is ended.;COPYRIGHT: (C)1998,JPO