Mel-scaled cepstrum

It is possible to perform a similar operation with LP coefficients. In the normal calculation of these, spectral representations aren t used and so scaling the frequency domain (as in the case of mel-scaled cepstrum) isn t possible. Recall however that in the autocorrelation technique of LP, that we used the set of autocorrelation functions to find the predictor coefficients. In Section... 

Perform an inverse liftering operation by padding the mel-scale cepstrum with zeros. This... 

Perform an inverse cosine transform, which gives us a mel-scaled spectrum. This differs from the analysis mel-scale cepstrum because of the liftering, but in fact the differences in the envelopes of the original and reconstructed spectra have been shown to be minor, particularly with respect to the important formant locations. 

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