Subject: mfcc filters gain From: Guillaume Lemaitre <lemaitre(at)IRCAM.FR> Date: Wed, 3 Nov 2004 17:32:43 +0100Dear list, In the Malcom Slaney's Matlab implementation of mel frequency cepstral coefficients, triangular filters are normalized "so that each filter has unit weight". Parsing some papers dealing with mfcc, I noticed that most of authors does not mention this normalization step (a few of them do, but without explanation). I am wondering what does this normalization correspond to. If I am correct, and if triangular filters were supposed to approximate critical band filtering, they all should have the same unit height, just as third octave, or Patterson's gammatone filterbank. Am I wrong ? I am also wondering if some work has already be done to improve mfcc-like processing. As it is suggested in [1], Moore's ERB scale or Bark scale seems to be more appropriated than the mel scale, and gammatone filterbank should be much more accurate (even if probably more computationaly expensive) than a triangular filterbank ? Regards Guillaume [1] M. D. Skoweonski and J. G. Harris "Improving the filterbank of a classic speech feature extraction algorithm" IEEE Int. Symp. on Circuits and Systems, Bangkok, Thailand, 2003 ------------------------------------------------------------------- Guillaume Lemaitre, Ph.D. Post-doctoral fellow Project-team REVES (REndering and Virtual Environments with Sounds) INRIA Sophia-Antipolis tel: (+33) (0)4 92 38 50 83 2004 route des Lucioles fax: (+33) (0)4 92 38 50 30 BP 93, F-06902 Sophia-Antipolis, France Guillaume.Lemaitre(at)sophia.inria.fr, ------------------------------------------