| 摘要 |
A method for implementing a speech verification system for use in a noisy environment comprises the steps of generating a confidence index for an utterance using a speech verifier, and controlling the speech verifier with a processor, wherein the utterance contains frames of sound energy. The speech verifier includes a noise suppressor, a pitch detector, and a confidence determiner. The noise suppressor suppresses noise in each frame in the utterance by summing a frequency spectrum for each frame with frequency spectra of a selected number of previous frames to produce a spectral sum. The pitch detector applies a spectral comb window to each spectral sum to produce correlation values for each frame in the utterance. The pitch detector also applies an alternate spectral comb window to each spectral sum to produce alternate correlation values for each frame in the utterance. The confidence determiner evaluates the correlation values to produce a frame confidence measure for each frame in the utterance. The confidence determiner then uses the frame confidence measures to generate the confidence index for the utterance, which indicates whether the utterance is or is not speech. |
