Rare frog turns deaf ear to distracting noises

CHICAGO _ With a twitch of a muscle, the Chinese concave-eared torrent frog brushes off the sounds of thundering rivers, focusing on the one thing that really matters:

The siren song of the opposite sex.

The rare frog is the only animal known to be able to turn a deaf ear to distracting noises while enhancing the calls of its own kind, according to a study published Monday in the Proceedings of the National Academy of Science.

When the frog is calling for a mate, a piece of cartilage in its Eustachian tubes _ the canals that connect the ears with the mouth _ largely blocks out distracting low-frequency sounds like rushing water. Scientists hope their discovery may lead to improved hearing aids.

"This probably is the only example we know of in the animal kingdom with this unusual adaptation," said Albert Feng, professor of molecular and integrative physiology at the University of Illinois and one of the study's lead authors.