Duke Hospital now uses the new Neuromonics Tinnitus Treatment system from Australia to help tinnitus sufferers. The system quiets the constant ringing noise of tinnitus.

It drives people nuts.

Ringing. Buzzing. Hissing.

For people with tinnitus, a phantom sound only they can hear plagues their every waking moment. Imagine a Salvation Army bell ringer camped out in your head every day, all day.

Despite afflicting an estimated 50 million people in the United States, often as a result of injury or repeated exposure to loud noises, the condition has no cures and few effective treatments, though a newer approach is now available at Duke University.

The intervention, called Neuromonics, retrains people to manage how they hear the internal sound. But it’s not covered by insurance and is expensive — about $4,500 for a device that resembles a portable music player and for sessions with an audiologist to tailor the treatment.

Teri Kim, 48, of Cary, N.C., started the therapy in August and almost quit a month into it when she still hadn’t gotten relief from the high-pitched whine that has blared in her head for years. Then she gradually began having good days and even good weeks as the whine began to diminish.

“It was wonderful,” Kim said.

The therapy works on the finding that many cases of tinnitus (pronounced teh-NYE-tus or TIN-eh-tus) are produced inside the brain, not the ear.

Rebecca Price, an audiologist at Duke who provides the therapy, said the internal sound is often accompanied by hearing loss. When the ear can no longer pick up a certain sound frequency, scientists theorize, the brain fills the void, causing a non-stop din.

For most, the sound is a minor nuisance, but about 12 million sufferers in the United States find it so troubling they seek medical help, according to the American Tinnitus Association, an advocacy group. About 2 million people claim some degree of disability from the disorder.

Brain imaging has provided researchers with clues to the cause, homing in on areas involved in auditory processing, as well as regions associated with memory and emotion.