Feature

A monotone speech might put an English-speaking audience to sleep, but to a Chinese crowd, it would be completely incomprehensible. This is because Chinese-speakers--along with half of the world--use pitch to convey words' meanings. For example, in the Chinese dialect of Mandarin, the word "ma" when spoken in a high pitch means mother, while "ma" in a lower tone means hemp. And because children speaking these languages learn to associate words with pitches, they may be up to nine times more likely to develop a rare musical ability known as absolute pitch, according a new study published in the Journal of the Acoustical Society of America (Vol. 116, No. 4). Popularly known as perfect pitch, absolute pitch is the ability to identify the letter-name of a sounded note--something only one in 10,000 Americans can do.

However, the study, coupled with research on infant pitch perception, suggests that absolute pitch--instead of being a rare, nearly magical ability--may be tied to early language development. And early exposure to pitches and their labels could make absolute pitch accessible to nearly anyone, says study author Diana Deutsch, PhD, a psychology professor at the University of California, San Diego.

"We're finding evidence of an absolute pitch module in everyone's brain, and I suspect it developed for speech," says Deutsch. "That we recognize pitch in music is a side effect."

Though experts disagree on the potential benefits of perfect pitch, Deutsch believes it could help people learn a tone language like Chinese later in life, as those with perfect pitch already can connect tones with words. Those with perfect pitch may hold advantages in musical tasks--such as singing in tune or composing music--as well, Deutsch notes.

Others, though, view perfect pitch as less important. "Perfect pitch is interesting, but not having it says nothing about whether you are a good musician or not," says Andrea R. Halpern, PhD, a psychology professor at Pennsylvania's Bucknell University who studies pitch perception.

However, those parents who want to hedge their bets may be able to increase their children's chances of gaining the skill, Deutsch says. Early experience playing on a piano with labeled keys or listening to adults match tones with words might allow any child younger than six to develop perfect pitch, she says.

Early music perception

New research on infant pitch recognition lends support to Deutsch's hypothesis. One such study, published in Developmental Psychology (Vol. 37, No. 1), finds that 8-month-olds recognize and remember absolute pitch, while English-speaking adults attend only to notes' relationship to each other. This finding suggests that at some point babies stop noticing absolute pitches because, at least for English-speakers, they offer little useful information, says study author Jenny Saffran, PhD, a psychology professor at the University of Wisconsin-Madison.

Saffran and her colleagues reached this conclusion by playing a random sequence of notes for 20 8-month-olds. Immediately afterward, half of the babies listened to a set of notes taken from the previously heard stream. The other group of infants listened to a set of notes that were the same tune as the original note stream, just transposed to a different key. That is, the notes' relationship to each other did not change, but their absolute pitches did.

The infants who heard excerpts from the note stream transposed to a different key paid attention to the recording about one second longer than the infants who heard the exact same pitches as before.

Babies pay more attention to novel sounds than ones they've recently heard, Saffran says. Therefore, the study suggests that infants recall the absolute pitch of notes and notice when they are transposed, she says.

Adults in a similar experiment, however, did not distinguish between the two groups of notes--they recalled the notes' relationship to each other, but not their pitches, Saffran adds.

"Somewhere along the line, we stop paying attention to absolute pitch," says Saffran.

In the English language, relative pitch plays a much more important role than absolute pitch, she says. A rising tone at the end of a sentence, for example, can turn a statement into a question. And that may be why babies exposed to English may quickly learn to ignore absolute pitch and instead focus on pitches' relationships, says Saffran.

In music, relative pitch generally plays a more important role than absolute pitch--as songs are frequently sung or transposed from one key to another, Saffran notes.

Tone languages

Mandarin speakers, however, must pay attention to absolute pitch to pin down the meanings of individual words, says Deutsch. And early practice linking words to pitches may give tone-language speakers an edge on learning absolute pitch, she notes.

Deutsch tested this hypothesis by playing 36 notes to a group of 88 Mandarin-speaking Chinese music students and 155 English-speaking American music students. The students wrote down the name of each note after hearing it played. The participants also indicated at what age they began their musical training.

Of the Chinese music students, 63 percent named the notes correctly--within a half step--at least 85 percent of the time. Of the American students, only 7 percent met the criteria for absolute pitch.

Also, both American and Chinese students who began their musical training before age 6 were more likely to develop the ability to name tones. This suggests that like a language's vowel sounds, pitch naming is learned during a critical developmental period, Deutsch notes.

However, pitch memory is only half of what goes into absolute pitch, says Gail Mauner, PhD, a professor of psychology and linguistics at the University at Buffalo of the State University of New York. The other half of the equation involves linking those notes to labels associated with frequencies, she says. (See sidebar.)

"Absolute pitch is maybe not what we are talking about here," says Mauner. "Saffran's infants are not labeling pitches; they are discriminating between pitches they have heard before and those they have not--which is certainly a prerequisite to developing absolute pitch."

Chinese speakers may have a leg up on making this link--allowing them to pick up perfect pitch as a kind of second language, says Deutsch.

"People who speak intonation [nontone] languages like English don't have that first language to work off," she says.

English-speaking parents who would like to give their children the edge that Chinese-speaking children have in learning absolute pitch should let their infants practice making the connection between words and notes, Deutsch suggests. This could be done, for example, by singing note names along with notes, or simply giving a child a labeled keyboard to bang on, she says.

Though experts debate the advantages absolute pitch brings, it's possible that people with absolute pitch find it easier to learn tone languages as adults, says Deutsch. Moreover, historical records suggest that musical giants such as J.S. Bach and Ludwig van Beethoven had the ability--so it can't hurt, she notes.