Smiling? You Can Hear It in the Voice

"When we listen to speech we hear the general pitch, and people associate a rise in pitch with more smiley sounding voices," she said, adding that "we might also be picking up on more subtle cues, like the spread of frequencies within the voice, and how intense the voice is."

A person with a naturally short vocal tract may therefore sound more smiley than others at all times.

How we perceive such smiles may influence our behavior.

Piotr Winkielman, associate professor of psychology at the University of California at San Diego, unconsciously primed some of his study participants with happy faces.

To do this, he showed them photos of faces. Pictures with the happy faces flashed by quickly, before the viewers could consciously detect them, while neutral faces were presented for longer periods. The photo viewers were then offered a drink and asked how much they would pay for it.

Volunteers primed with the subliminal smiles drank more and offered to pay up to triple the price of the offered beverage, which was just a sugary Kool-Aid mixture.

"This is the first demonstration that you can influence consequential, real-world behavior without affecting conscious feeling," Winkielman said. "We can change what you do without changing how you feel."

In future, studies on smiles and other expressions might improve synthetic voices used for disabled individuals. They could also benefit a host of other applications, such as computer games, automated phone systems, text-to-speech technologies and more.

Related Links:

Jen Viegas' blog: Born Animal

School of Health Sciences and Social Work at the University of Portsmouth

Face Reading

What's in a smile?