A new method of Cepstrum analysis by using comb lifter

This paper describes the use of comb lifter in the Cepstrum analysis which is usefull for extraction of formant frequencies. Good result is obtained with Han lifter in case of low pitch frequency. But, in case of high pitch frequency, the separation of two formants is sometimes impossible. The comb lifter is presented to overcome this difficulty, that is, the length of the lifter is fixed so as to separate the closest formants, and the peaks in the cepstrum due to the periodicity of speech are suppressed by using comb lifter. Successful results have been obtained in the experiments using two types of comb lifter. A new type of adaptive lifter is also presented which does not need the pitch detection and is useful in case of connected speech.