Singing in congenital amusia.

Congenital amusia is a musical disorder characterized by impaired pitch perception. To examine to what extent this perceptual pitch deficit may compromise singing, 11 amusic individuals and 11 matched controls were asked to sing a familiar tune with lyrics and on the syllable /la/. Acoustical analysis of sung renditions yielded measures of pitch accuracy (e.g., number of pitch errors) and time accuracy (e.g., number of time errors). The results revealed that 9 out of 11 amusics were poor singers, mostly on the pitch dimension. Poor singers made an anomalously high number of pitch interval and contour errors, produced pitch intervals largely deviating from the score, and lacked pitch stability; however, more than half of the amusics sang in-time. Amusics' variability in singing proficiency was related to their residual pitch perceptual ability. Thus, their singing deficiency might be a consequence of their perceptual deficit. Nevertheless, there were notable exceptions. Two amusic individuals, despite their impoverished perception, sang proficiently. The latter findings are consistent with the existence of separate neural pathways for auditory perception and action.