Noise Is a Leading Cause of Hearing Loss
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 protection.
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."