Evidence for distinct types of ‘‘perfect pitch.’’

Abstract

The ability to identify and reproduce sounds of specific frequencies, typically called ‘‘perfect pitch,’’ is remarkable and uncommon. Whether this skill is learned early in life or inherited has been a matter of great controversy. Further, a substantial literature suggests that ‘‘perfect pitch’’ may be heterogeneous. Previously, we proposed a model to account for heterogeneity. The model subdivides individuals capable of naming notes accurately into two groups: possessors of true absolute pitch (AP), who automatically encode the frequency of all tonal stimuli, precategorically and independent of their source; and possessors of heightened tonal memory (HTM), who identify tones by comparing them to a memorized tonal template. The ability of individuals with HTM to identify tonal stimuli should depend strongly on the tones’ acoustical properties, such as timbre or chroma. Three experiments sought to test this hypothesis directly. Individuals claiming ‘‘perfect pitch’’ were recruited and initially classified as having AP or HTM. Consistent with the model, the two groups differed significantly in their sensitivity to the targets’ timbre, chroma, and tonal context, suggesting that they may use different mechanisms to identify tonal stimuli. The model may help reconcile the long-standing controversy between early learning and genetic theories of ‘‘perfect pitch.’’