Abstract

Ancient and medieval scholars considered tones related by simple (small-integer) ratios to be naturally pleasing, but contemporary scholars attribute the special perceptual status of such sounds to exposure. We investigated the possibility of processing predispositions for some tone combinations by evaluating infants' ability to detect subtle changes to patterns of simultaneous and sequential tones. Infants detected such changes to pairs of pure tones (intervals) only when the tones were related by simple frequency ratios. This was the case for 9-month-old infants tested with harmonic (simultaneous) intervals and for 6-month-old infants tested with melodic (sequential) intervals. These results are consistent with a biological basis for the prevalence of particular intervals historically and cross-culturally.