Susie Reust lost the hearing in her right ear due to a brain abscess—and says she lost much of her life as well.

"It's very isolating. People think you're stupid because you don't respond to them," says the 45-year-old financial manager for a hospital chain in Phoenix.

In January, Reust tried a new hearing system that transmits sounds wirelessly through the teeth. Leaving the audiologist's office, she says she almost cried when she heard a sound on her right—high heels clicking on the sidewalk—for the first time in 10 years.

"To this day, I'm constantly clicking a pen near my right ear, just for the joy of hearing it," she says.

The aptly named SoundBite system relies on bone conduction—the ability of sound waves to travel from teeth through the bones in the skull.

It isn't a hearing aid, which amplifies sound in frequencies where peoples' hearing is diminished. It is aimed instead at people who are completely deaf in one ear, often because of a problem in the cochlea, the spiral-shaped structure in the inner ear. About 8 million Americans were born with single-sided deafness and another 1.5 million developed it later in life, sometimes overnight for mysterious reasons. SoundBite can also help people with untreatable conductive hearing loss, which can be caused by trauma to the ear drum or chronic ear infections.

SoundBite effectively bypasses such damage. A tiny microphone in the patient's deaf ear picks up incoming sounds; a processor worn behind the ear transmits the signals wirelessly to a receiver hooked over the patient's back molars like a mini retainer. That sends the sound waves on through the teeth, into the skull to the functioning cochlea, which sends the signals on to the brain. Users can eat and talk while wearing the mouth device, which is invisible from outside.

The device costs $6,800 and is currently available in a pilot launch at 42 major hearing centers in the U.S. Its maker, Sonitus Medical, hopes to win Medicare coverage for it before making it more widely available, says CEO Amir Abolfathi, who also helped develop invisible braces for teeth. Insurers generally don't cover traditional hearing aids, but a few have covered SoundBite as a prosthetic device.

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