BACKGROUND: Tinnitus is defined as the perception of sound in one or both ears or in the head when no external sound is present. It is often called "ringing in the ears," although some people hear hissing, roaring, whistling, chirping or clicking. Though statistics vary, according to the American Tinnitus Association, more than 50 million Americans experience tinnitus to some degree. Of these, about 12 million people have tinnitus severe enough to seek medical attention. About 2 million people are so debilitated by the noise that they can't function on a day-to-day basis.

WHAT CAUSES IT? According to the American Academy of Otolaryngology, Head and Neck Surgery, most tinnitus comes from damage to the microscopic endings of the hearing nerve in the inner ear. In older people with tinnitus, the tinnitus could result from hearing nerve impairment that often comes with advancing age. In younger people, the leading cause of tinnitus is exposure to loud noise.

In some cases, allergy, high or low blood pressure, a tumor, diabetes, thyroid problems, or injury to the head or neck could be behind the tinnitus. Medications such as anti-inflammatories, antibiotics, sedatives, antidepressants and aspirin might also cause it. The first step toward quieting the noise is to make an appointment with a specialist called an otolaryngologist.

SLEEP AND TINNITUS: Tinnitus can often interfere with patients' ability to go to sleep and stay asleep. Jay Piccirillo, M.D., from Washington University in St. Louis, says, "They are sitting there, staring up at the ceiling listening to the sound. It can be very distracting." He studied the drug melatonin to help people with tinnitus improve their sleep. Patients taking one pill a night not only experienced improved sleep, but also a decreased perception of tinnitus. Dr. Piccirillo says, "I would definitely think that patients with tinnitus who are having problems sleeping should consider melatonin." Melatonin is considered by many doctors to be a safe drug and is approved by the FDA as a sleep aide. Despite being available over the counter, it is always a good idea to talk to your doctor before starting any new therapies.

HELP ON THE HORIZON: There are studies on other treatments for tinnitus currently underway. Dr. Piccirillo is studying repetitive transcranial magnetic stimulation to help quiet the noise. In this therapy, a magnet is placed outside the brain and generates a small electrical signal. Patients undergo the therapy once a day for three weeks. In a small study, patients noted a decrease in the sound of tinnitus. Dr. Piccirillo has applied for funding to do a much larger study.

Researchers from the California Ear Institute are studying the use of Botox to help tinnitus. By giving three injections of Botox around the most affected ear, researchers found some patients reported some relief of tinnitus symptoms. The study was small and researchers say the results need to be repeated in a larger study before Botox is recommended or discarded as a tinnitus treatment.