The use of sub-band cepstrum in speaker verification
This paper focuses on the spectral representation of the sub-band cepstrum in relation to that of the full-band cepstrum. Through theoretical analysis it is shown that the net spectral information content of the cepstral coefficients with the same index in different sub-bands is only comparable to that of a full-band cepstral parameter whose quefrency is given by the product of that specific index with the number of sub-bands. A new method is proposed to tackle this deficiency of the sub-band cepstrum when it is used in the context of text-dependent speaker verification. The experimental investigations have clearly demonstrated the effectiveness of this method in speaker verification.