The present invention comprises a system and method for speech verification using an efficient confidence measure, and includes a speech verifier which compares a confidence measure for a recognized word to a predetermined threshold value in order to determine whether the recognized word is valid, where a recognized word corresponds to a word model that produces a highest recognition score. In accordance with the present invention, the foregoing confidence measure may be calculated using the recognition score for the recognized word and a pseudo filler score that may be based upon selected average recognition scores from an N-best list of recognition candidates.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a Continuation-In-Part of, and claims the benefit of, U.S. Provisional Application No. 60/160,859, entitled "System And Method For Speech Verification Using A Confidence Measure," filed Oct. 21, 1999, as well as U.S. Non-Provisional Application No. 09/553,985, U.S, Pat. No. 6,473,735, entitled "System And Method For Speech Verification Using A Confidence Measure," filed Apr. 20, 2000, both of which are hereby incorporated by reference.
The present invention comprises a system and method for speech verification using a robust confidence measure, and includes a speech verifier which compares a confidence measure for a recognized word to a predetermined threshold value in order to determine whether the recognized word is valid, where a recognized word corresponds to a word model that produces a highest recognition score. In accordance with the present invention, the foregoing confidence measure may be calculated using the recognition score for the recognized word, a background score of a worst recognition candidate, and a pseudo filler score that may be based upon selected average recognition scores from an N-best list of recognition candidates.
A speech recognition system is used to receive a speech signal and output an output language word with respect to the speech signal. The speech recognition system has preset quantities for a first threshold, a second threshold, and a third threshold. The speech recognition system includes a first speech recognition device that is used to receive the speech signal and generate a first candidate language word and a first confidence measurement of the first candidate language word, according to the speech signal. A second speech recognition device is used to receive the speech signal and generate a second candidate language word and a second confidence measurement of the second candidate language word, according to the speech signal. A confidence measurement judging unit is used to output the language word, by comparing the first confidence measurement and the second confidence measurement to the above thresholds.
