Two bionic ears better than one: study

From: Ninemsn - Sydney,New South Wales,Australia - Mar 29, 2007

Two bionic ears are better than one for profoundly deaf people, according to new research which rejects current beliefs.

An Australian hearing psychologist says the extra cochlear implant - an Australian invention - improves sound and confidence enough to make it worthwhile for the most hearing impaired people.

Most are fitted with just one as previous research had shown there were no benefits in doubling up.

University of New England professor Bill Noble worked with Iowa researchers to analyse data collected from more than 180 deaf US patients fitted with either one or two implants.

It was the largest-scale subjective assessment of cochlear implants, also known as bionic ears, to be undertaken so far.

"The responses of these patients indicate that a second implant can increase confidence in a social context, make it easier to understand speech in a noisy environment, and significantly enhance the ability to locate sounds," Prof Noble said.

"It can also enhance the quality and 'naturalness' of sounds."

A recent British study concluded that the added benefit from a second implant did not justify the additional expense.

"After analysing the Iowa data, I would not go along with that," he said.

The cochlear implant, developed by Melbourne specialist professor Graeme Clark, is an array of electrodes inserted into the inner ear to directly stimulate the auditory nerve.

Designed for people with severe hearing loss, it can lead to a dramatic improvement on what can be achieved with even the best acoustic hearing aids.

The benefit was not "dramatic", but it enhanced quality of life enough to be justified, Prof Noble said.

"These findings could contribute to the formation of future public policies on the treatment of severe hearing loss," he said.

©AAP 2007
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