Music on more than one note: Pitch perception and neural coding of concurrent harmonic tones.

Abstract

The basis of Western music lies in the combination of simultaneous (harmony) and sequential (melody) harmonic complex tones or notes. Listeners must “hear out” simultaneous pitches and “track” pitch sequences over time. Surprisingly few psychoacoustic studies have studied pitch perception under such “natural” conditions of more than one note at a time. Similarly, the neural mechanisms that support these abilities remain poorly understood. Here, we will review psychoacoustical and neurophysiological findings, which concur to suggest an important role for frequency selectivity in the ability of the auditory system to segregate concurrent notes. In particular, the ability to accurately discriminate changes in the fundamental frequency or, subjectively, pitch of a “target” harmonic complex tone in the presence of a “masker” tone occupying the same spectral region seems to covary with the limits peripheral frequency selectivity. Given that harmonic complex tones are an important class of sound for both music and speech and that frequency selectivity is usually adversely affected by cochlear damage, such results may have important implications for the current understanding of auditory scene analysis of concurrent music and speech sounds and of the listening difficulties experienced by hearing‐impaired individuals. [Work supported by NIH Grant R01 DC05216.]