SSS 2009-09-28（在线收听）

Ever get a ringing in your ears after a loud blast of music on your iPod? That’s one example of the usually temporary condition called tinnitus, the sensation of sound even when no sound is being produced. But a new invention—created by high school students—may help.

The cochlea in the ear converts sound waves to electrical impulses that the brain processes as sound. Thousands of tiny hairs in the cochlea bend when exposed to the original sound vibrations. But those hairs can get stuck in a bent position. Which is why we hear the sound even when it’s gone.

Two young women in Ireland were studying the problem in physics class. They thought that a low hum might straighten out those bent cochlear hairs. So they developed a minute-long therapy using the hum and tested it on 250 subjects.

Ninety-nine percent of the tinnitus sufferers said the treatment got rid of the disturbing phantom sound. The two 18-year-olds and their physics teacher have now launched a company called Restored Hearing. Good news for the iPod generation from two of their own, who fought fire with fire. Or rather, sound with sound.

—Cynthia Graber