Bizarre frog tunes ears to specific frequencies

... University of Illinois professor Albert Feng says the frog known as "Odorrana tormota" is the only known animal that actively selects what frequencies it hears. He pointed out that the frogs seem to possess an ability to tune in to specific sound frequencies as circumstances change. For instance, when the low frequency background noise makes it too difficult for them to discern the calls of potential mates or rivals, the frogs' hearing can switch to high frequency and ultrasonic hearing levels. There's a reason why people outside of frog enthusiasts and people with very weird hobbies should care. Earlier research into the mechanics of frog hearing helped Feng and his colleagues design an "intelligent hearing aid" that boosts sound signals. - cnet