Another thing to look for is deleted or very flat energy between harmonics. Reducing bit rate in inter harmonic regions is most of what's meant by 'psychoacoust

Another thing to look for is deleted or very flat energy between harmonics. Reducing bit rate in inter harmonic regions is most of what's meant by 'psychoacoustics.' I imagine low pass filtering depends a bit on which compression you're using. None of these tricks will work for detecting GAN compressed audio, though.