BOB HIRSHON (host):
How trills improve communication. I’m Bob Hirshon and this is Science Update.
At least six different types of mammals have calls with trills or bleats, like these sheep [bleating sheep] and this panda [panda bleating]. Why is bleating so popular? To find out, Benjamin Charlton at University College Dublin, and his colleagues played two series of very similar sounds to human volunteers. One of the series had been modulated to have a bleating effect, like this: [synthetic bleating].
In the journal Current Biology, they report that the bleating helped volunteers distinguish between sounds that had subtle differences in important sound characteristics called formants. Formants can help tell a large animal from a small one, and also help a parent identify its offspring. So bleating helps animals pick up important information about callers, even if they’re all calling at once. [bleating sheep together] I’m Bob Hirshon, for AAAS, the science society.
Story by Bob Hirshon