Absolute pitch recognition is an interesting and relatively rare ability. It involves a number of complex and subtle processes, starting with the transformation of acoustical signals into electrical impulses in the cochlea, and ending with the still unknown mechanisms of pitch memorization and recall. Within the framework of the 12-tone scale, the possessors of absolute pitch are able to name the note corresponding to the pitch they hear; some possessors are also able to produce (by singing) the pitch of a requested note. Many aspects of this phenomenon (its genesis, relation to categorical perception, stability etc.) have been studied extensively; for reviews see Ward and Burns (1982) and Takeuchi and Hulse (1993).
We report here our study of a patient who, while taking a psychoactive drug, noted a disturbing change in her sense of absolute pitch. A randomized double-blind investigation revealed a systematic change in her pitch recognition.
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