| Jan 21, 2010
Normal hearing begins with a sound wave. The wave enters the external ear canal and causes a thin membrane of tissue, the eardrum, to vibrate. These vibrations are translated through the middle ear by three small bones – malleus, incus and stapes, or hammer, anvil and stirrup – to the cochlea. It is here that tiny hair cells move in response to the vibrations and begin the nerve impulses to the brain to be interpreted as specific sounds.
Individuals with tinnitus hear sounds in the absence of sound waves. Tinnitus, from the Latin tinnire, meaning “to ring,” is a bothersome sound or noise in the ear. It can be in the form of a ringing, hissing, whistling, buzzing, roaring or clicking. Approximately 10 to 15 percent of the population experiences tinnitus. It most commonly occurs between the ages of 40 to 70, and is equally seen in men and women.
There are many possible causes of tinnitus. The most common is noise-induced hearing loss. Prolonged exposure to loud noises from occupational exposure, loud music or gun shots can damage the hair cells in the inner ear. It is thought that the damaged hair cells send repetitive impulses through the auditory nerve to the brain, thereby inducing a continuous sense of sound or tinnitus.
Other common causes of tinnitus include progressive loss of hearing acuity from aging, injury from ear infection, a build-up of wax in the ear canal, head injury, metabolic disorders, such as high or low thyroid, vitamin deficiencies and anemia, stress and medications. Over 500 different medications list tinnitus as a potential side effect. One commonly used medicinal culprit is aspirin.
One specific disease associated with tinnitus is Meniere’s disease. In this condition, there is an excessive amount of fluid (endolymph) within the inner ear. Sufferers of the disease experience a sudden onset of fullness in one ear, tinnitus, vertigo and hearing loss. During an “attack,” the tinnitus can be described as a roaring sound. Over time, repetitive attacks can lead to permanent tinnitus and hearing loss.
Treating tinnitus involves finding and eliminating the cause. Individuals who are experiencing tinnitus should first consult with their regular physician. Hearing tests will often be employed to evaluate potential hearing loss. Sometimes imaging studies can be done to identify structural abnormalities, such as a tumor in the acoustic nerve. Blood studies may pick up a metabolic cause.
In many cases, however, there is no identifiable and treatable cause. In others, it may resolve spontaneously. Though some may perceive their symptom as no more than a mild annoyance, there are people with severe tinnitus who are debilitated by the condition. These people may benefit from therapies such as hearing aids, sound therapy, behavioral counseling and/or medications.
As with most medical conditions, prevention is very important. Limit excessive noise exposure and use hearing protection whenever possible. One final point, the carbon monoxide and benzene present in cigarette smoke have been linked to damaging effects on the ear’s hair cell structures. Smoking cessation is always a good health choice.
The content in this column is for informational purposes only. Consult your physician for appropriate individual treatment. Dr. Reynolds practices Family Medicine in Chesterfield.