A segment-based C/sub 0/ adaptation scheme for PMC-based noisy Mandarin speech recognition
Wei‐Tyng Hong, Sin‐Horng Chen · 1999
A segment-based C/sub 0/ (the zero-th order of cepstral coefficient) adaptation scheme for PMC-based Mandarin speech recognition is proposed in this paper. It incorporates a new C/sub 0/ model of speech signal into the PMC method to improve the gain matching between the clean-speech HMM models and the current noise model. The C/sub 0/ model is constructed in the training phase by jointly modeling the normalized C/sub 0/ with other MFCC recognition features to form C/sub 0/-normalized HMM models. In the testing phase, it pre-segments the input utterance into syllable-like segments, performs C/sub 0/-denormalization operations to expand the C/sub 0/-normalized HMM models, and uses them in the PMC method. Compared with the conventional PMC method, the proposed method can achieve a much better noise compensation effect due to the use of more precise gain matching in the PMC model combination. Experimental results showed that the base-syllable accuracy rate was significantly upgraded for continuous noisy Mandarin speech recognition.