How to get a non-equally spaced FFT back into the time domain I have a signal that I STFT and then filter using an ERB spaced filterbank. At some point after this I want to get the signal back into the time domain, how can I go about this? Using a standard iSTFT function won't work because it assumed linearly spaced frequency bins, AFAIK? I've put a code snippet below.
I'm also not sure what what to tag this question as apart from fourier-transform
Y = stft(sig) # Y.shape = (1025,4000)
fb = filterbank() # fb.shape = (20,1025)

Y_erb = matrix_multiply(fb,Y) # Y_erb.shape = (20,4000)
```
The short answer is that you can solve a least squares problem with the input signal as the decision variables.
About Nonequispaced FFT
There is a related question in stack overflow.
If you are not using python, you can take a look into the nfft github.
Here will find some information. Section 4.6 covers the inversion of such transforms.