TINNITUS CAUSES AND DEMOGRAPHICS
Tinnitus is more common in men, seniors, blue-collar workers, military personnel, and people with common health problems, such as arthritis, hypertension, varicose veins, and arteriosclerosis. All of these associations are probably explained by one simple correlation: The worse your hearing is, the more likely you are to have tinnitus.
Roughly 90 percent of tinnitus cases occur with an underlying hearing loss, regardless to whether the damage is in the inner ear or the middle ear, or what otologic disorder has caused it.
Age-related hearing loss, or presbycusis, can occur whether or not someone has experienced significant noise exposure, ear infections, or any other specific ear disease. Presbycusis continues to progress with age and is usually more severe in men than in women. As a result, as shown in epidemiological surveys, the prevalence of tinnitus is higher in men and increases with age.
These same surveys generally show that the next most important risk factor for hearing loss and tinnitus, after age and gender, is excessive noise exposure. It is generally true that the louder the noise and the longer the exposure, the greater the hearing loss.
People who have regular and prolonged exposure to noise, usually at work (such as military personnel or construction workers), begin to be at risk of permanent hearing loss and tinnitus at levels of about 85 decibels (dB), which is roughly equivalent to the sound of heavy city traffic. At this level, most people would need to speak very loudly or even to shout to converse with someone only at arm’s length away.
Outside of the workplace, one of the most important sources of harmful noise exposure is recreational shooting. But any noise exposure that causes temporary tinnitus or muffled hearing can, if regularly repeated, lead to permanent hearing loss and tinnitus. This includes unsafe listening to personal MP3 players.
There are also many ear disorders other than age-related and noise-induced hearing loss that cause hearing loss and tinnitus. Sensorineural hearing loss can be caused by genetic mutations, by some drugs used to fight infection and cancer, or by head injuries. Conductive hearing loss is often caused by chronic ear infections or otosclerosis, a hereditary middle ear disease.
Content is adapted from “Overview: Suffering From Tinnitus,” by Robert A. Dobie, M.D., a chapter in “Tinnitus: Theory and Management,” edited by James B. Snow, Jr., M.D. It appears with permission from Dobie, Snow, and PMPH-USA, the publisher.