From CNN.COM:

Can't carry a tune? Blame your genes

March 9, 2001 Web posted at: 11:59 AM EST (1659 GMT)

WASHINGTON (Reuters) -- If you can't carry a tune -- or even recognize one -- it's probably not your fault. A new study released Thursday indicates tune-deafness is mostly in your genes.

This finding could potentially have implications for people with speech disorders related to how they perceive various pitches, according to National Institutes of Health researcher Dennis Drayna.

In terms of how good people are at recognizing tunes, "it looks like it's mostly genetic," Drayna said in a telephone interview.

To determine this, Drayna and his fellow researchers tested hundreds of pairs of twins, all women. About half of the twin pairs were fraternal and half identical, so that if a trait was purely genetic, the identical twins would be expected to both have it.

The test involved first testing their hearing for any impairment, and then playing snatches of 26 easily recognizable melodies from "The Star Spangled Banner" to "Silent Night" to "The Marseillaise". Some of the tunes were correctly played, others were distorted, and the twins were asked to determine which was which.

As expected, the identical twins all performed the same as their respective twins, whether their tune recognition was good or poor. The fraternal twins, whose genetic makeup was not exactly similar, did not correlate quite so well.

Most people did fairly well, about 15 percent made some modest errors, and about 5 percent were truly tune-deaf, Drayna said. That meant that the really terrible ones often did worse on the test than they would have done by simply guessing.

The study found that the ability to recognize tunes is between 70 percent and 80 percent genetic, with the rest attributable to environmental factors, such as the person's musical experience.

This was somewhat surprising, Drayna said, since many educators believe this trait can be changed by training. In the case of the absolutely tune-deaf, there probably is not much hope for this, he said.

"If you have terrible pitch recognition, you're going to have it regardless," Drayna said.

The study also found that hearing deficits did not necessarily change a person's ability to recognize tunes; much of pitch-recognition takes place in the brain.

"This does have some clinical implications in speech and language pathology, because perception of speech is very dependent on pitch," Drayna said.

"People with severe deficits in pitch recognition could have problems with speech and there is some anecdotal evidence that that is what's going on in certain kinds of speech disorders," he said.

He said his findings about pitch recognition might have implications for some classes of speech problems.

This research was published in the journal Science.