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Elephant Talk: -National Geographic, Vol. 176(2), August, 1989, p. 264
et seq.
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Pill Trumpeted as Hearing Saver
Worried by the many sailors who damage their hearing with heavy ships' guns and jet engines, the US Navy has come up with a pill to prevent hearing loss from loud noises. And a private company licensed to bring the pill to market says it should provide protection for people going to rock concerts and using jackhammers and other deafening equipment.
The secret, says American BioHealth Group of San Diego, is in protecting the thousands of tiny hair-shaped cells deep inside your ear, cells that die off slowly in the days or weeks after you blast them with noise. They believe the key to protecting those hairs lies in a drug soldiers could take before going into battle or rock fans could swallow before a concert.
"In all cases what we've been able to show is that if this [drug] is administered prior to the noise...you're nearly completely protected from hearing damage," said company president Mark Mugerditchian. "If you take the compound after the noise exposure, we can still nearly, completely repair any hearing damage. Damage to these hair cells is the main cause of hearing loss," he said. "You have a certain number of them, and when they die they don't get replaced."
The drug is a group of antioxidants, a chemical that does some of the same job as vitamin C. Antioxidants get rid of unattached atoms called free radicals that roam through the body and react with molecules in our cells, causing damage.
The US Office of Naval Research in San Diego began work on an anti-deafness pill because the navy is paying $69 million a year in compensation for hearing loss on the job.
A loud noise makes sensitive cells in the ear produce a sudden overload of free radicals, which in turn kill off the hair cells in the ear. These are cells that vibrate in response to sounds, and send a signal which the brain identifies as a sound. In a period of days to weeks after loud noise, these hair cells die off. It's a physical break in the chain between sounds in the outer world to the brain, and it causes partial or total deafness.
Two navy doctors experimented on chinchillas to test their drug. "It has almost identical similarity to our hearing sensitivity," Mugerditchian said. They exposed chinchillas to loud noises over a period of time, and others to one sudden bang like a gunshot.
American BioHealth has signed on to take the drug through clinical trials in humans. It has finished one of the three phases of clinical trials needed to get a drug to market. Mugerditchian said it will take at least five more years to get approval to market the drug.
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Argentine Pigeons Suffer: -National Post (Canada), July 17, 2002
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Right to Quiet Society Newsletter, Fall, 2002