Neural sensitivity to phase of high frequency tones

The response of fibres of the auditory nerve and neurons of the inferior colliculus of the cat to harmonic two-tone complexes was studied. The components (primaries) had frequencies which were integral multiples of the characteristic frequency of the cell under study. This gave rise to distortion products at the characteristic frequency of the cell. The response of these cells to distortion products at their characteristic frequency was found to be dependent upon the relative phase of the primaries. This was observed for primaries of high frequency as well as those of low frequency. The response to distortion in the cochlear microphonic was also dependent upon the relative phase between harmonic primaries.