Noise Is a Leading Cause of Hearing Loss
WebMD News Archive
June 16, 2000 -- The world is a noisy place. Stereo headphones can blast
music into both ears at sound levels equal to that of a diesel locomotive.
Power tools meant for home use can create levels of noise once heard only by
workers in high-risk occupations. Snowmobiles, leaf blowers, and motorcycles
add to the din.
It's no wonder that noise-related hearing loss is the second most common
form of acquired deafness (aging is in first place). And many experts believe
that much of the hearing deficit that comes with increasing age is related to
the cumulative effect of noise.
The inability to hear sounds at high frequencies, and the inability to
understand speech -- the kind of hearing loss associated with noise -- is
becoming such a problem that Peter M. Rabinowitz, MD, MPH, was prompted to
review the causes and preventive steps for physicians in a recent issue of the
American Family Physicians. "Physicians who stress preventive care
should be aware of noise-induced hearing loss, since it is 100%
preventable," Rabinowitz tells WebMD.
To help educate patients who come to the doctor for other reasons,
Rabinowitz also has written an informational guide that physicians can
distribute in their waiting rooms. "How to Prevent Noise-Induced Heart
Loss" explains how to tell if noise might be harming your ears. For
instance, it says: "If you have to shout when you talk to a coworker who is
standing next to you, the noise level at your workplace may be hurting your
ears." The "shout test," Rabinowitz says, can be used in any
situation to determine if you should be using earplugs or other types of
Noise is harmful because it damages cells within the cochlea, a snail-shaped
organ within the ear. These cells have tiny hairlike projections that are
stimulated by sound. The stimulation is transferred by nerves to the brain,
where it is interpreted as sound. The delicate cells of the cochlea can repair
themselves if damaged, but eventually, permanent damage may occur.
"If the ears are overstimulated by, say, [music at] a rock concert, your
ears may ring or feel like they have cotton in them for a day or two. The cells
may recover. That's called a 'temporary threshold shift,'" Rabinowitz says.
"But if that goes on too many times, or is too severe, the [cells] can't
recover, and they die. You're born with a certain number of hair cells, and
that's all you have."