If someone plunks a random piano key, a tiny minority of people can identify the note based on its sound alone. These people boast perfect pitch, the ability to recognize individual sound frequencies without any external reference. But even these gifted few are not truly perfect. A new study shows that their errors, though subtle, provide a previously unseen glimpse into how biological and environmental factors together shape hearing.
Absolute pitch, commonly known as perfect pitch, results from the confluence of early musical training and a rare genetic endowment. Yet the neurology underlying absolute pitch (and its converse, congenital tune-deafness, or amusia) remains obscure. In the new study, researchers identified about 1,000 people who could instantly and effortlessly label each of a series of randomly presented acoustical tones. Results revealed that people with absolute pitch formed a distinct clump of scores, far outside the normal range of ability. “There are people who have this exquisitely perfect pitch-naming ability, and the rest of us are just guessing,” says the study’s lead author, geneticist Jane Gitschier of the University of California, San Francisco. That fact, combined with previous family heritability studies, suggests that, unlike most complex traits, perfect pitch may be governed by only one gene or at most very few.