Utterance verification method and apparatus for isolated word n-best recognition result

An utterance verification apparatus for an isolated word N-best speech recognition result comprising:

• a pre-processor for extracting a feature vector of an input utterance and performing endpoint detection;
• an N-best speech recognizer for performing N-best speech recognition through Viterbi search by referring to the context-dependent phoneme model extracted from the feature vector;
• and
• an N-best utterance verification unit for calculating log likelihoods of a context-dependent phoneme and an anti-phoneme model for the N-best speech-recognized word, comparing a confidence score measured for the N-best speech-recognized word with a threshold, comparing a distance measured for the N-best speech-recognized-word with a mean of distances, and accepting the N-best speech-recognized word when the compared results for the confidence score and the distance correspond to acceptances.