Air Date: Week of October 4, 2002

Living on Earth’s Maggie Villiger reports on how crickets are able to make an earsplitting racket without deafening themselves.

Transcript

CURWOOD: Just ahead, the pleasures and perils of the end-of-summer fair. First, this page from the Animal Notebook with Maggie Villiger.

[ANIMAL NOTE THEME MUSIC]

VILLIGER: Being loud is a good way to get your message heard. Just listen to the racket a tiny cricket can make.

[CRICKET CHIRPING]

VILLAGER: But if you listen to a sound at this level for too long, you run the risk of deafening yourself and missing important sounds in your environment.

Now, scientists have figured out how crickets stop their ears from being blown out. A particular part of the insect’s brain is responsible. When a cricket sings its rhythmic song, it’s thanks to an impulse sent out by the region of its brain called the central pattern generator.

This network of neurons sends out two copies of its message at the exact same time. One is sent to the cricket’s muscles, telling the wings to rub together and generate the noise. At the same time, another dampening signal goes to the part of the brain that processes auditory input.

So at the same moment, the muscles get the message to sing, the auditory system gets the message to shut down. In between its bursts of song, the cricket’s hearing returns to 100% so he can hear other sounds around him—hopefully, the approach of a romantic female. That’s this week’s Animal Note. I’m Maggie Villiger.

[ANIMAL NOTE THEME MUSIC]

CURWOOD: And you’re listening to Living on Earth.

[MUSIC: Miles Davis, "Right Off," A TRIBUTE TO JACK JOHNSON (Columbia, 1992)