Auditory-motivated filterbank

The auditory-motivated filterbank decomposes the observed signal f(t) into complex spectra X_k(t). This filterbank is implemented as a constant Q gammatone filterbank that is constructed with K=128, a bandwidth of 60-6000 Hz, and a sampling frequency of 20 kHz [Unoki and Akagi1997]. S_k(t) and $\phi_k(t)$ are determined by using the amplitude and phase spectra defined by the wavelet transform [Unoki and Akagi1997].