Why some voices sound more attractive

Some people's voices seem to have been made for the radio. Others grate on our nerves.

At the University of California, Santa Cruz, Grant McGuire is figuring out why. He's studying what acoustical features tend to make a human voice sound more attractive.

In data presented at an upcoming meeting of the Acoustical Society of America in Cancun, Mexico, he asked volunteer to listen to recordings of 60 people talking and rate how attractive they sounded. He then analyzed the acoustic characteristics of these voices.

"Males and females for the most part agreed on what an attractive male or female voice sounds like," says McGuire.

His study, which included only Californians, didn't set out an exact definition for "attractive" -- it left that up to the listeners. But it did find three features that tend to make a voice sound attractive.

First, we seem to like voices that use the same dialect that we do. The Californians preferred voices that pronounced the word "dude" with the fronted "oo" vowel that the West Coast is known for.

"The more Californian you sound, the more attractive you are going to be to other Californians," says McGuire.

Secondly, we don't like voices that sound creaky -- that slight rasp or rattle that some voices have. Instead, we prefer breathier-sounding voices.

"If you want to avoid having a creaky voice, don't drink a lot or smoke a lot," says McGuire.

Finally, the scientists found a connection between the size of man's vocal tract -- the distance between the vocal folds and the mouth -- and the attractiveness of his voice. Longer vocal tracts tend to cause different resonances in the voice that tend to be considered more attractive.

It's a connection that evolutionary psychologists, who seek to explain psychological traits as adaptations, find puzzling -- why, they wonder, would we prefer a longer vocal tract?

Grant McGuire will present the findings at the 2nd Pan-American/Iberian Meeting on Acoustics on Friday, November 19.