Combined psychophysical and electrophysiological study on the role of combination tones in the perception of phase changes

Publisher Website
Google Scholar
Abstract
It is a psychophysical fact that phase changes in a 3-component signal are audible provided that the frequency separation between the components does not exceed a critical value. A possible source of these effects is the phase-dependent level of the internal components caused by an interaction within the ear of acoustic frequency components and combination tones of the form (n + 1)f1 - nf2. This hypothesis was tested by psychophysical and electrophysiological experiments. The level of the internal component as a function of phase was psychophysically estimated in a forward-masking experiment in man. Single cell recordings in the cochlear nucleus of the cat were performed to investigate the phase dependence. The interaction between acoustic components and combination tones was demonstrated for both experimental approaches. It could be described as a vector addition. Subsequent psychophysical and electrophysiological experiments on the detectability limits of combination tones showed that these limits correspond to the maximum frequency separations for the audibility of phase changes.