Speech recognition system utilizing vocabulary model preselection

摘要

Preliminary screening of vocabulary models is provided by successively applying two different high speed distance measuring functions which provide progressively increasing measurement accuracy. Both distance measuring functions utilize subsampled representations of the unknown speech segment and the vocabulary models. The initial screening function achieves very high speed by eliminating certain usual time warping constraints and by precalculating a table of distance values which can be used for all vocabulary models. The second screening function yields improved accuracy in spite of possible endpointing errors by comparing extra frames, preceding and following the presumed unknown word, with noise models appended to each vocabulary model.