Nearly 12 million Americans suffer from tinnitus, ringing in the ears that can stop and start or continue non-stop. In addition to ringing the sound can resemble a roar, squeal, whine, buzz, click, hiss, or hum and can affect one ear or both. In at least one million cases, tinnitus is severe enough to interfere with daily activities; the disorder is so distracting that people can't hear, work or even sleep.

Most tinnitus is due to damage to the microscopic endings of the hearing nerve in the inner ear, commonly from exposure to loud noise. Other causes include allergy, high or low blood pressure, a tumor, diabetes, thyroid problems, a head or neck injury. Some drugs including anti-inflammatories, antibiotics, sedatives, antidepressants and aspirin can cause tinnitus. If you take aspirin and your ears ring, we suggest talking to your doctor about dosage in relation to your size.

Recent research also found that a specific area of the brain involved in tinnitus that affects only one ear. Using positron-emission tomograph (PET), researchers at the State University of New York in Buffalo were able to detect changes in the auditory cortex, the part of the brain that processes sound, on the opposite side of the brain from the tinnitus. The researchers said that this suggests that tinnitus may be initiated by brain activity rather than by the ear.

The average tinnitus makes a 7,000 hertz tone, for comparison, the highest note on a grand piano makes a noise in only the 4,000 hertz range. With that in mind, you can see how tinnitus might monopolize your attention.

Because it is the real perception of a phantom sound, it can be difficult for the people around someone with tinnitus to understand what the person is going through, says Stephen Nagler, M.D., director of the Southeastern Comprehensive Tinnitus Clinic in Atlanta.

“Just because the sound exists only in your head doesn’t mean you’re crazy. The tinnitus sufferers have lost their silence. It’s an incredible loss. It’s incredibly real,” Dr. Nagler says.