Frequency-warping and speaker-normalization

We have proposed the use of scale-cepstral coefficients as features in speech recognition. We have developed a corresponding frequency-warping function, such that, in the warped domain the formant envelopes of different speakers are approximately translated versions of one and another for any given vowel. These methods were motivated by a desire to achieve speaker-normalization. In this paper, we point out very interesting parallels of the various steps in computing the scale-cepstrum, with those observed in computing features based on physiological models of the auditory system or psychoacoustic experiments. It may therefore be useful to have a better understanding of the need for the various signal-processing steps which may result in the development of more robust recognizers