Patent ID: 6292778
Filing Date: 2001-09-18
Classification: G10L

Abstract:
An automated speech recognition system comprising:a speech information preprocessor for receiving a speech signal and responsively producing at least one speech feature signal descriptive of said speech signal;a speech recognition component responsive to said speech feature signal to produce a speech recognition hypothesis indicating which member of a predefined group of sound units most probably corresponds to speech content of said speech signal; andan utterance verification component responsive to said speech recognition hypothesis and said speech feature signal for producing an acceptance signal when said speech content of said speech signal includes said speech recognition hypothesis;said utterance verification component having a first subword acoustic model distinct from any acoustic model used to produce said speech recognition hypothesis for determining a first likelihood that a speech segment contains a sound corresponding to said speech recognition hypothesis;said utterance verification component having a second subword acoustic model for determining a second likelihood that a speech segment contains a sound other than one corresponding to said speech recognition hypothesis;wherein said first and second subword acoustic models have been trained through obtaining correct recognitions by force-segmenting sample sentences using a correct lexical transcription, obtaining incorrect recognitions by force-segmenting sample sentences using an incorrect lexical transcription, and for each subword in a sample sentence adjusting parameters of each of said first and second subword acoustic models according to whether recognition of such subword was correct.