A tunable, nonsubsampled, non-uniform filter bank for multi-band audition and level modification of audio signals

The need for investigation and (possibly non-linear) modification (e.g. dynamic range compression) of the components of an audio signal corresponding to different spectral bands is widespread. Two examples of present focus include multi-band dynamic range compression of a musical signal and frequency-dependent gain control in a hearing aid. We present a technique we call sub-band audition, which enables the user to listen to individual sub-bands of an audio signal, and thus better determine required modifications. The filter bank requirements of such an application are presented. Finally, the design of a tunable, nonsubsampled, non-uniform filter bank, based on allpass-complementary filter banks and elliptic minimal Q-factor (EMQF) filters, is presented.