Pitch perception: a difference between right- and left-handed listeners.

Various results indicate that the perception of a complex tone's "virtual" pitch is generally lateralized in the right cerebral hemisphere. The primary aim of this work was to test the hypothesis that this is not the case for the "spectral" pitch percepts induced by complex tones. Forty right-handed and 18 left-handed listeners were monaurally presented with pairs of successive tones made up of n consecutive equal-amplitude harmonics of a missing fundamental (F0). n varied from two to four across subjects. In "test" conditions, the paired tones differed in F0 but the spectral components of the tone with the lower F0 were higher in frequency than the corresponding components of the other tone (except for one component, which was identical). The subjects had to say if, from one tone to the other, pitch rose or fell. From such judgements, one could infer that the pitch dominantly perceived in each tone was a virtual pitch (corresponding to F0) or a spectral pitch (i.e., the pitch of a single spectral component, or a perceptual quality corresponding to the centroid of the power spectrum). For n = 2, the results indicated that virtual pitch was less salient than spectral pitch; the opposite occurred for n = 3 and n = 4. The ear (left or right) to which the stimuli were presented had some influence on the judgements, in the expected direction. However, this influence was not a robust one. Unexpectedly, a reliable effect of the listeners' handedness was observed: for each value of n, the judgements indicating virtual pitch perception were less frequent in the left-handers than in the right-handers. Discrimination performances measured in "control" conditions showed that the handedness factor was not confounded with a factor of frequency discrimination ability.