New Hearing Device Filters Unwanted Noise

M E N L O  P A R K, Calif., Dec. 17 -- The song of a bird. The rustle of leaves in the wind. The buzz of a bee. Most people don't give these sounds of daily life a second thought. For Sherry Dumont, though, they are a daily wonder.

She was almost totally deaf for nearly 20 years but now can hear again, thanks to a cutting-edge device that sends wireless signals to her hearing aid.

"Tapping a pencil on a table — I've never heard that before," Dumont, 37, says with wonder in her voice. "The computer makes noise — I didn't know that." Once, standing in he kitchen, she asked her husband what a certain noise was. "And it was the refrigerator. It never occurred to me that the refrigerator made a noise."

The device, called a Directional Hearing Array, is the creation of Bernard Widrow, a Stanford University electrical engineer.

For the severely and profoundly deaf — the 2 million Americans with the worst hearing loss — standard hearing aids amplify everything, including background noise and echoes. Widrow's device solves that problem by using six tiny microphones — instead of a standard hearing aid's one — in a curved plastic casing that is worn around the neck. Signal-processing electronics inside give different weights to the sounds picked up by each microphone, focusing on what the user wants to hear and reducing the extraneous noise, especially from the side and behind.

"By cutting out noise all around, the result is you greatly reduce the noise without reducing the amplitude of the signal or voice you'd like to hear," says Widrow.

It's the same principle the military uses in radar and sonar to overcome jamming.

The device costs about $2,500, which is about the cost of a standard hearing aid. Private insurance generally does not cover the cost of hearing devices.

Ending Isolation

Dumont, the chief financial officer for two small companies, says the Directional Hearing Array allows her to be more effective at work. Before she got the device, she relied on lip-reading and had trouble following discussions involving many people. Now, she can conduct meetings.