From the time he was a young boy, Wolfgang Amadeus Mozart could identify musical notes simply by hearing them played on a piano. Mozart possessed absolute or perfect pitch, a trait that has long mystified scientists who study this sort of stuff: Are people born with it? Or do they learn it? 

Now, researchers from the University of California, San Diego, have identified another clue to solving the mystery of perfect pitch: Whether or not you know the note might be down to your genes. 

“I have always been sort of wondering why I developed perfect pitch," says Diana Deutsch, a professor of psychology at UCSD, who remembers being able to instantly identify musical notes when she was as young as 4 -- despite having minimal musical training. "Even the grown-ups had to look and see what note was being played on a piano,” she recalls. 

Deutsch and her colleague Kevin Dooley -- who, incidentally, also has perfect pitch -- presented their findings this week in Kansas City, Mo., at the Acoustical Society of America's annual meeting. 

The debate over perfect pitch has long focused on nature versus nurture. People who speak tonal languages -- which rely heavily on inflection to differentiate between words -- are more likely to possess absolute pitch than non-tonal language speakers. For example, in Cantonese, “ma” can mean either "mother" or "horse," depending on how the speaker says it. Even though tonal language speakers are more likely to possess perfect pitch, non-tonal language speakers sometimes have it if they start musical training at a young age. But there are plenty of musicians without absolute pitch.   

Deutsch developed perfect pitch without training, which is true for many with perfect pitch -- and that suggests a genetic correlate, she explained. She wondered if it was related to an unusually large auditory memory, and so she and Dooley designed an experiment to see how pitch correlated to short-term visual and auditory memory.

They asked 27 English-speaking students or recent college graduates, seven of whom possessed perfect pitch, all of whom had started music lessons at age 6 or younger, to participate in a memory exercise, testing digit span. Digit span looks at how well people remember a series of numbers when they see them on a computer screen or hear them. 

Both groups of students—those with absolute pitch and those without—listened to strings of numbers, followed by a visual digit span test. In the auditory test, those with perfect pitch recalled 10 digits, while those without remembered 8.1. (The perfect pitch-ers were also slightly better at remembering the numbers from the visual test than the non perfect pitch-ers, but only marginally so.) The ability to recall a string of numbers after hearing them has been linked to a person's genetics, and because Duetsch found that people with a large auditory digit span also possessed absolute pitch, she believes there might be a genetic link for pitch, too.  

Up next, Deutsch plans to continue her research, perhaps looking at the non-musically trained family members of the subjects with perfect pitch to see how they rank on the digit span test. 

Related:

Can't carry a tune to save your life? You may be amusic

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Screeeeeeeech. Even imagining the sound of a person's fingernails scraping down a chalkboard is horrible. Now, new research helps suggest why the noise is such a special kind of awful. 

The frequency of the screechy, scratchy sound ranges between 2000 Hz and 4000 -- and to your ear canal, this is the zone of terror, where the human ear is most sensitive. "Some frequencies are amplified due to the anatomy of the ear canal," write musicologists Christoph Reuter, of the University of Vienna, and Michael Oehler, of the Macromedia University for Media and Communication in Cologne, Germany. In other words: Blame the shape of your ear.

In Reuter's and Oehler's study, they played two unpleasant sounds -- fingernails on a chalkboard and squeaking chalk on a slate -- but before doing so, they told half of their participants that they'd be hearing contemporary music. The other half knew the horror that was coming. Both groups reacted physically to the sounds, which induced a galvanic skin response -- a change in the skin's electrical activity that is often triggered by fright and can be measured, like a polygraph test. Those who thought they were listening to contemporary music judged the sound as slightly less unpleasant -- but they still didn't like it, suggesting psychology plays a role in what makes the noise so noxious. 

Reuter and Oehler presented their finding this week at the Acoustical Society of America meeting. 

Feeling uncomfortable after all this fingernails-on-chalkboard talk? Researchers actually proved in a 1986 study just thinking about nails-on-a-chalkboard can evoke the same psychological reaction as actually hearing the horrible sound.

Can you think of a sound that's worse than fingernails on a chalkboard? (Silverware scraping on plates? Styrofoam rubbing together?) 

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