# Old style signal processing?

I am wondering if "an array of overlapping band-pass ﬁlters" it is 'mostly' equivalent to a Short-Time Fourier transform. See this (figure down), where $$s(t)$$ is the signal; LPF a second-order low-pass ﬁlter with a resonance frequency of 4 kHz; BPF an array of band-pass ﬁlters, where frequencies that are spaced equidistantly on a critical band scale; HCM a hair cell model which is assumed identical in all channels, and finally a low-pass ﬁlter at 1250 Hz does an envelope extraction of the patterns in each channel. Processing a signal with this method produces a matrix of intesities that are vertically distributed like in STFT.

What are the differences between them? Could be improved with wavelets as basis?

• if the HCM are identical for all bands, i think you need to bump down the frequency of the outputs of the BPFs down to a common low-frequency baseband. otherwise, if you don't, the HCM for the higher frequency bands need to work with higher frequencies than the HCMs for the lower bands. that might be simply a parameter change for qualitatively identical models, but they can't be exactly identical. – robert bristow-johnson Aug 14 '19 at 2:08