Pitch perception in normal and impaired hearing

Abstract

Despite a century-long debate, there is little consensus on how pitch is coded. This talk will focus on recent psychoacoustic studies that have attempted to shed light on some of the basic principles of pitch coding. The pitch associated with melodies and music is conveyed mainly by lower-numbered harmonics, which are thought to be individually resolved in the peripheral auditory system. When the lower harmonics are removed, the pitch percept becomes weaker and dependent on the phase relations between harmonics, as expected with unresolved harmonics that interact within the passbands of peripheral auditory filters. A number of studies in normal and impaired hearing have shown a connection between harmonic resolvability and pitch strength or salience. However, there are reasons to doubt the causality of this relationship. The evidence for whether resolved harmonics are necessary or sufficient for salient pitch will be reviewed. Finally, some experiments related to the use of pitch cues in segregating speech from competing interferers will be discussed, with particular reference to whether the cues that produce strong pitch salience in psychoacoustic tasks are also those that are most useful in promoting segregation. [Work supported by NIH Grant R01DC05216.]