Eh? What's that? A pill to prevent ear damage?

NEW YORK - Scientists have been accumulating evidence in lab animals for years that a pill might be able to reduce the damage loud noise does to your hearing. Now they're sending in the Marines.

Starting in a few months, a group of 600 Marines at Camp Pendleton in California will face rifle training with not only foam plugs in their ears, but also a drink that tastes very much like Wild Berry Zinger herbal tea.

It's the latest wrinkle in research toward finding a pill that will protect against and even treat hearing loss from exposure to loud noise. While the effort is hardly new, experts say it has picked up steam.

About 10-million Americans have permanent hearing loss from loud noise, either a long-term exposure or in a sudden burst.

These days, much of the work focuses on antioxidants, the chemical class that most famously includes vitamins C and E.

That's because loud noise doesn't always damage the delicate inner ear immediately just by brute force. Rather, in most cases it provokes the inner ear into making harmful oxygen molecules called free radicals. Antioxidants neutralize free radicals, and the ear naturally has such defenses. But with enough noise, the ear's antioxidants are overwhelmed.

In that case, damage from the free radicals leads to death of the ear's sound receptors - hair cells, which convert sound waves into nerve messages to the brain.

Antioxidants should work best if given before noise exposure, but animal work suggests it might reduce permanent hearing loss substantially if given within four to eight hours, said Col. Richard Kopke, a researcher.

In the experiment with the Marines, half will get an antioxidant compound called N-acetylcysteine or NAC in their flavored drink and the other half won't. Then researchers will see if the first group fares better.

© 2006 • All Rights Reserved • St. Petersburg Times 490 First Avenue South • St. Petersburg, FL 33701 • 727-893-8111 Contact the Times | Privacy Policy Standard of Accuracy | Terms, Conditions & Copyright