Device That Produces Tiny Skull Vibrations A Big Help For Hearing Impaired

Main Category: Hearing / Deafness
Also Included In: Medical Devices;  Clinical Trials / Drug Trials
Article Date: 26 Apr 2008 - 0:00 PDT

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Although Jim McGinn of Wheaton is completely deaf in his right ear, he still can hear from that side.

A sound processor McGinn wears just behind his right ear converts sound waves into tiny vibrations that move through his skull. The vibrations are detected by his good left ear, so it sounds to McGinn like he can hear from both sides.

A Loyola University Health System study has found that this system of conducting sound through skull bone is a big boost to people who are deaf in one ear and can't be helped by hearing aids or cochlear implants.

Sixty Loyola patients were asked to compare their hearing before and after getting the system, called Baha. Their ability to hear in a quiet environment improved by 28 percent, the trouble they had with background noise decreased by 33 percent and the difficulties they experienced with reverberating sounds in such settings as churches and lecture halls was reduced by 29 percent. The only downside: there was a 7 percent increase in the annoyance caused by loud sounds such as fire truck sirens.

"People are hearing much better," said V. Suzanne Jeter, an audiologist at Loyola Oakbrook Terrace Medical Center.

Jeter presented the study at the 10th International Conference on Cochlear Implants and Other Implantable Auditory Technologies in San Diego.

Each year, more than 60,000 people in the United States become deaf in one ear due to such causes as chronic ear infections, congenital conditions, inner ear disease, injuries or tumors.

McGinn, a retired accountant, lost hearing on his right side due to an acoustic neuroma, a benign tumor in the inner ear. At the dinner table, he struggled to hear what people to his right were saying. And when driving his car, he couldn't hear the passenger.

A Loyola surgeon implanted a small titanium post in McGinn's skull, behind his right ear. The sound processor clips on to this post. The battery-operated processor is roughly the size of an adult thumb, from the tip to the first knuckle. A microphone picks up sound waves, and a computer chip converts the sound waves into electrical signals that vibrate the skull. These tiny vibrations, which McGinn can't feel, travel to the inner portion of his left ear, where they are detected as sound. McGinn removes the sound processor when showering or sleeping.

"It's a dramatic difference," McGinn said. "I'm getting conversation from around the table now, not just from the left side."

Since 2004, Loyola doctors have put the device in 130 patients. The total cost per patient ranges from $10,000 to $15,000. Medicare and most insurance plans cover it, Jeter said.

Jeter's study is the largest of its kind on the device. Jeter said she receives no funding from Cochlear Americas, which makes the device.

Loyola University Health System
2160 S. First Ave.
Maywood, IL 60153
United States
http://www.luhs.org