Two stages of bandwidth scaling drives efficient neural coding of natural sounds
Fig 6
Fourier and midbrain modulation filterbanks.
Modulation decomposition filters are shown for (A) the midbrain filterbank and (C) the Fourier-based filterbank, with each transfer function contoured at the 3dB level (50% power). Note that the Fourier-based modulation filters have equal resolution in both spectral and temporal dimensions, whereas the midbrain modulation filters have proportional resolution as observed physiologically (i.e., bandwidth scaling). The corresponding STRFs are shown for both the (B) midbrain filterbank and (D) Fourier-based filterbank. Note that the Fourier-based STRFs have equal duration and bandwidth whereas the durations and bandwidths scale for midbrain filters.