Ears May Have Natural Defense Against Loud Noise, Mouse Study Shows
Researchers suspect humans have a similar system to guard hearing
FRIDAY, Feb. 20, 2015 (HealthDay News) -- Ears have a natural mechanism to help protect them against extremely loud and damaging noises, new research suggests.
Researchers pinpointed a connection from a part of the ear known as the cochlea to the brain that warns of intense incoming noise. The cochlea is the hearing part of the inner ear.
This noise alert system may be the reason you stick your fingers in your ears when there is an extremely loud sound nearby, such as the siren of an emergency vehicle, the research team explained.
"It's very important for your system to have protection from damaging sound," study senior author Jaime Garcia-Anoveros, an associate professor of anesthesiology from Northwestern University Feinberg School of Medicine in Chicago, said in a university news release.
"When sensory hair cells in the ear die, they are not repopulated. That's why hearing loss is irreversible. You need to be able to detect dangerous sound the way your nerve cells alert you to the danger of putting your hand on a hot iron," explained Garcia-Anoveros, who is also an investigator at the university's hearing center.
The study was conducted in mice, but the investigators believe people have a similar system. They want to research this pathway in humans. Experts note that research in animals often fails to translate to humans.
Details of the study appear in the Feb. 20 issue of Nature Reviews Neuroscience. The study was also published in Current Biology.
The findings could improve understanding and treatment of conditions such as tinnitus (a persistent ringing in the ears) and hyperacusis, an oversensitivity and earache in response to everyday sounds that is common among soldiers who have been exposed to explosions.
"We do not know how to treat these debilitating conditions, and understanding what neuronal pathway might be involved is essential," Garcia-Anoveros said. "If we find they are actually pain syndromes rather than hearing syndromes, perhaps they could be treated effectively with analgesic pain medication that acts on the brain."
The U.S. National Institute on Deafness and Other Communication Disorders has more about noise-induced hearing loss.