Pitch perception and frequency-following response in inharmonic signals.

Abstract

It has been suggested that auditory-evoked frequency-following response (FFR) is related to pitch [Greenberg et al., Hear. Res. 25, 91–114 (1987)], which is usually related to fundamental frequency of complex sounds. We examined FFR to dual-tone multi-frequency (DTMF) signals used in telephone communication. As these tones have been used to produce melodies, it was expected that they would have a measurable pitch and this was also determined in a behavioral task. Twelve subjects matched perceived pitch of DTMF signals to a pure tone via method of adjustment. In addition, the FFR to the same signals was recorded from the same subjects to establish whether significant FFR energy was present at the frequency of the perceived pitch. Correlation analysis of data from the behavioral task showed wide variation among subjects, with many identifying the perceived pitch as matching the lower of the two partials. Significant FFR energy was detected at both partials, which does not clarify the relationship between perceived pitch and the evoked response. In addition, we show that perceived pitch is highly context dependent and present data from FFR to stimuli in melodic contexts.