Exploring the acoustic basis of consonance using individual differences.

Abstract

Despite its central role in music, the origins of the preference for consonant over dissonant intervals remains controversial. We applied an individual differences approach to this question. Subjects were first tested for their aversion to pure-tone beats, and to inharmonic spectra of single complex tones. Consistent individual differences were observed in the magnitude of subjects’ aversion to beats and inharmonicity, but the two effects were uncorrelated across subjects, suggesting independent factors. Subjects then rated the pleasantness of musical intervals and three-note chords. If particular acoustic factors determine consonance, stronger sensitivity to those factors should predict stronger musical preferences. In each of two cohorts, only the preference for harmonic spectra was consistently correlated with preferences for consonant over dissonant chords and intervals. Although the strength of a subject’s consonance preference was also correlated with their musical experience, so was their harmonicity preference, which explained most of the effect of experience on consonance ratings. The results suggest that much of consonance perception is rooted in the basic acoustic property of harmonicity. Harmonicity is evidently predictive of important structures in Western music, and with exposure to music, listeners learn to attend to it. [Work supported by NIH grant R01DC05216.]