We humans are pretty good at communicating with sounds other than words [sound of laughter]. But how much of this is hard-wired, and how much do we pick up from others?

To find out, researchers recorded the nonverbal sounds of people born deaf, as they responded to a range of positive and negative emotions. The idea being that if certain sounds are learned, deaf people wouldn't know how to make them.

Then they played back those recordings for a group of hearing individuals, to see if they could decipher the emotion behind each sound. They guessed correctly more than chance would predict—deaf people’s sounds of amusement and relief were pretty obvious. Which suggests we may be born primed to laugh or sigh.

But the listeners had a tough time with these two: [deaf female sound, deaf male sound]. Those are both expressions of triumph. Here’s a hearing person’s [hearing male sound].

So the researchers say certain nonverbal sounds may require experience to learn—just as in language. They'll present the findings at a meeting of the Acoustical Society of America. [D. Sauter, O. Crasborn and D. Haun, "The role of perceptual learning in emotional vocalizations"]

Their theory fits nicely with a previous study, which found that shouts of triumph vary from culture to culture. Maybe that explains why some people can’t stand the vuvuzela.

—Christopher Intagliata

[The above text is an exact transcript of this podcast.]