DEAR MAYO CLINIC:

Five months ago, I woke up with severe ringing in my left ear. The ringing stopped after a couple of days but returned three months later and is now in both ears. It's a mix of a constant high-pitched buzzing, ringing and a whistling sound. I've had four hearing tests, all normal for my age (38). What caused this? Is treatment available?

ANSWER:

The condition you're describing is called idiopathic bilateral subjective tinnitus. What causes tinnitus is unclear, and a cure for this disorder currently isn't available. But a variety of treatment options can help reduce the bothersome symptom of tinnitus.

Tinnitus involves the sensation of hearing sound when no external sound is present. As in your situation, the sound may take the form of buzzing, ringing or whistling. Tinnitus may also involve roaring, clicking or hissing noises. The noise may vary in pitch from a low roar to a high squeal in one or both ears. In some cases, the sound can be so loud it interferes with a person's ability to concentrate or hear. Tinnitus may be present all the time, or it may come and go.

Many theories have been advanced as to why tinnitus occurs, but no clear-cut cause has been proven. We do know that the perception of tinnitus symptoms is perpetuated and maintained in the hearing centers within the brain. In some cases, an underlying medical condition may cause tinnitus, such as inner ear cell damage, age-related hearing loss, and toxins that gain access to the inner ear (ototoxicity), among others. Long-term exposure to loud noise may also result in tinnitus. But in many cases, an exact cause is never found.

Unfortunately, there are no medical or surgical cures for tinnitus. However, many strategies are available that can make tinnitus symptoms less disturbing. Environmental noise that can mask and help suppress tinnitus is helpful for most people with the disorder. People often use machines that play natural sounds -- thunderstorms or ocean waves, for example -- to mask the noise of tinnitus. These machines are particularly beneficial at night when a person's surrounding environment is at its quietest.

Hearing aids can also help people who have both hearing loss and tinnitus. Using a hearing aid brings more natural outside sounds to the ear, distracting the brain from focusing on the abnormal internal sounds of tinnitus. For people who have normal hearing and tinnitus, noise-masking devices worn on the ear are an option. These devices look similar to a hearing aid and play a low level of white noise to redirect the brain's attention away from the tinnitus sounds.

If, despite treatment, symptoms continue to be disruptive, tinnitus retraining therapy (TRT) may be useful. This therapy typically involves a 12- to 18-month program that uses a combination of sound enrichment, education and behavioral therapy to help alleviate the negative emotional reaction to tinnitus.

At this time, many researchers are working to find better treatments for those who have tinnitus, providing hope for future advances in tinnitus therapy.

I suggest you talk to your doctor or make an appointment with a physician who specializes in ear, nose and throat disorders (otorhinolaryngologist) to discuss your symptoms and develop a treatment plan that fits your situation. Even though a cure isn't available, effective treatment exists that can decrease the effect of tinnitus on your daily life.

-- Brian Neff, M.D., Otorhinolaryngology, Mayo Clinic, Rochester, Minn.

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