A modified constant-Q transform for audio signals

The paper proposes a new transform for musical audio signals. The new transform, so-called modified constant-Q fast filter bank (mCQFFB), yields a log-like description in the frequency domain with improved frequency response when compared to the standard DFT. The improved frequency response of the mCQFFB is achieved by interpreting the sliding-DFT (sDFT) as a multi-stage filter bank, and substituting the sDFT basic filter in this description by a higher-order filter with improved characteristics. The logarithmic spectral scale of the mCQFFB is achieved by the adequate resampling of a chosen channel filter. We also discuss implementation issues related to the mCQFFB and exemplify its application to the analysis of musical signals.