EUROSPEECH 2001 Scandinavia

We show that vocal tract normalization (VTN) frequency warping results in a linear transformation in the cepstral domain. For the special case of a piecewise linear warping function, the transformation matrix is analytically calculated. This approach enables us to compute the Jacobian determinant of the transformation matrix, which allows the normalization of the probability distributions used in speakernormalization for automatic speech recognition.
Bibliographic reference. Pitz, Michael / Molau, Sirko / Schlüter, Ralf / Ney, Hermann (2001): "Vocal tract normalization equals linear transformation in cepstral space", In EUROSPEECH2001, 26532656.