cepstrum

cepstrum

[′sep·trəm]

(acoustics)

The Fourier transform of the logarithm of a speech power spectrum; used to separate vocal tract information from pitch excitation in voiced speech.

cepstrum

(mathematics)

(Coined in a 1963 paper by Bogert, Healey, and Tukey) The Fourier transform of the log-magnitude spectrum:

fFt(ln( | fFt(window . signal) | ))

This function is used in speech recognition and possibly elsewhere. Note that the outer transform is NOT an inverse Fourier transform (as reported in many respectable DSP texts).