Naval Medical Center in San Diego has successfully tested a technique
that restores hearing loss if administered within hours following exposure
to loud noise.
FOR IMMEDIATE RELEASE
July 31, 1998
Office of Naval Research
Office of Congressional and Public Affairs
WASHINGTON, D.C.-- In a medical breakthrough that will help tens of millions
of Americans at risk for noise-induced hearing loss, the Naval Medical
Center in San Diego has successfully tested a technique that restores
hearing loss if administered within hours following exposure to loud noise.
It can also "inoculate" users against hearing loss if taken
before such exposure.
The technique uses micro-devices or micro-catheters inserted in the ear
to deliver antioxidant pharmaceuticals that protect the hypersensitive
hair cells within the ear that are fundamental to sound detection. These
pharmaceuticals have already been approved by the FDA for other applications;
it is anticipated that the antioxidants will be on the fast track for
approval for the clinical trials using human subject of this research.
Although the ear can tolerate an amazing range of sound intensities, a
day of 85 dB noise, the equivalent of standing behind a gas lawn mower,
can begin to damage the cochlea. Damage rapidly escalates with sound level
exposures to 120 dB sound pressure level, the equivalent of standing in
front of the speakers at a rock concert. At around 130 dB sound pressure
level, mechanical destruction of the inner ear begins. Excessive noise
initially damages the inner ear by generating toxic oxygen-containing
compounds that damage nerve endings and hair cells by chemical means.
Although damage begins soon after noise exposure, actual hair cell loss
does not begin for four to five days and progresses over the next 40 days.
This presents a window of
opportunity in which damaged hair cells may be rescued through the administration
of antioxidant pharmaceuticals.
"The techniques have already been used to treat hearing loss and
Meniere's diseases, and have significant implications for treating other
hearing and balance disorders in the military and civilian population,"
says co-principal investigator, Dr. Richard D. Kopke, Colonel, Army Medical
Sponsored by the Office of Naval Research and the U.S. Navy Bureau of
Medicine and Surgery, this research addresses issues of critical concern
to the United States military.
The military spends more than $1.5 billion in compensation, re-training,
and equipment replacement each year due to hearing and balance disorders,
More than 11 percent of individuals in the military are affected by these
disorders, Deafness affects 30 million Americans and costs the nation
$56 billion per year. An additional 40 million individuals work in environments
that pose a significant threat to their hearing, 50 percent of individuals
suffer a balance disorder at some point during their lifetime.
To further address hearing and balance problems that affect military and
civilian personnel, the Defense Spatial Orientation Center (DSOC) was
established. Dr. Michael Hoffer, Lieutenant Commander, Navy Medical Corps,
co-principal investigator with Dr. Kopke, explains that the group is "unique
in that it brings together investigators from a number of different centers"
to bring medical treatment directly to where military personnel work.
For more information or to arrange for interviews, contact the Office
of Naval Research Public Affairs, Loretta DeSio 703-696-5032 or Cynthia