sunday, november 7, 1999
Perfect pitch there at birth but easily lost?
Study looks at tonal languages
New York Times
The brain acoustic processes tones in, certain regions of the temporal lobes, Neural cells. I at different points in, those regions are sensitive to different tones.
But while most people find it easy to perceive and sing musical tones relative to one another, an ability called relative pitch, the ability to place them on an absolute scale is much less common. Absolute or perfect pitch turns up in no more than one person out of 10,000 in Western countries, according to some estimates.
The languages studied in the new research were Vietnamese and Mandarin Chinese, two major languages in which different rising and falling tones can impart different meanings to the same combination of vowels and consonants. For example, the Mandarin word ma can mean "mother," "hemp," "reproach" or "horse," depending on whether the spoken tone is flat, rising, falling, or falling and then rising.
While the differences in meaning are conveyed largely by relative rather than' absolute pitch, the researchers, led by Dr. Diana Deutsch, a psychologist at the University of California-San Diego, found that speakers retain an absolute tonal standard.
In the study, which Deutsch described Thursday at a meeting of the Acoustical Society of America, the researchers recorded Vietnamese and Mandarin speakers as they read lists of words that covered a wide range of tones, and then repeated the exercise days later.
A computer analysis of the recordings showed that individual speakers uttered the same words at the same absolute pitches to within fractions of a semitone - the musical step from one key on a piano to an adjacent one.
"It really sounds as though the person is sitting there immediately repeating the sound," Deutsch said. "Which is really, to my mind, amazing."
Exploring the connection
While the new findings have surprised many scientists, some said that more research needs to be done to show that the ability displayed by Vietnamese and Mandarin speakers is identical to perfect pitch as it is understood in music.
"It is still possible that the subjects may not actually see or realize a connection between tone as they use it in language and pitch as a musical concept," said Dr. Donald Hall, a physicist at California State University-Sacramento who studies musical acoustics and is a church organist with perfect pitch.
Some scientists said the new findings suggest that most babies are born with perfect pitch but retain it only by learning a tonal language or undergoing some sort of early musical training.
"There could be a much higher incidence of absolute-pitch musicians out there if all of us were exposed to music much, earlier," said Dr. Gottfried Schlaug, a neurologist at the Beth Israel Deaconess Medical Center in Boston who' has studied how' structures in the brain are related to absolute pitch.
'Pitch memory'
Others believe that most people, even in Western countries, do retain an almost perfect "pitch memory" but simply lack a means of giving names to each pitch and putting the ability into practice, as speakers of tonal languages can do.
"What it means to me is that people have a very accurate memory for musical pitch," said Dr. Daniel Levitin, a cognitive psychologist at McGill University in Montreal who has studied perfect pitch "You and I don't have the ability to attach these labels to it."
Another conceivable explanation for the results could lie in innate differences between Western and Asian populations, but Deutsch dismissed that possibility as "extraordinarily unlikely.",
For the study, Deutsch, a psychologist, collaborated with Trevor Henthorn, an audio engineer at the Center for Research in Computing and the Arts of UCSD, and Dr. Mark Dolson, a specialist in audio signal processing at the Creative Advanced Technology Center of the company Creative Technology Limited in Scotts Valley, Calif.
In one series of measurements, the team asked seven native speakers of VIetnamese to read a list of words that, spanned the range of tones in that language. Days later, the task was repeated, and recordings of each word were broken up into five-millisecond intervals, on a computer and analyzed for their average tonal content.
The differences of pitch between the two repetitions of a word by a particular speaker were all less than 1.1 semitone, and four of the seven speakers displayed pitch differences of less than half a semitone.
The results for 15 Mandarin speakers were perhaps even more striking, with nearly all of the speakers. showing differences of fractions of a semitone from session to session.
How many of the speakers displayed what is usually called perfect pitch? "You could argue that they all did," Deutsch said. "If people show it, give or take a semitone, they'll claim perfect pitch."
The unexpected results, Deutsch said,, raise the question of why perfect, pitch seems to, be so rare in the West.
One possible explanation, she said, is that most babies are capable of acquiring perfect pitch, just as they can learn to speak any language without an accent.
But as some window of time begins to close - earlier for some children, later for others - they can no longer acquire perfect pitch or speak a new language without an accent.