A new cepstrum-based channel compensation method for speaker verification

A new cepstrum-based channel compensation method is proposed for speaker verification over the telephone network. The method consists of intra-frame and interframe cepstral processing. For the former, a poleremoved cepstrum is derived, where the LP poles with frequency higher than a certain threshold are removed. For the latter, we introduce a novel way of cepstral mean subtraction called differential-partial cepstral mean subtraction (DPCMS). The main idea is that the cepstral mean of clean speech is not necessarily zero and that the cepstral difference between clean and channel-corrupted speech is mainly contributed by the channel effects on LP poles within a certain frequency range. A speaker verification system based on radial basis function networks was used to evaluate the proposed approach. Clean speech was used to train the networks and telephone speech was used to evaluate their performance. Experimental results show that the proposed method reduces verification error rate significantly.