German scientists find important mechanism of human hearing system

German scientists have found an important mechanism of human's hearing system that helps filter out substantial noise, said University of Leipzig on Thursday.

This could help to improve the quality of hearing aids, according to University of Leipzig.

Neurobiologists at the University of Leipzig deciphered how excitatory and inhibitory neurotransmitters interact together in the transmission of information between nervous cells.

The new findings have been published in the current issue of "Journal of Neuroscience."

Many hearing impaired people don't use a hearing aid, maybe because the devices do not deliver what they promise, said Rudolf Ruebsamen, professor of General Zoology and Neurobiology at the University of Leipzig.

Because a hearing aid basically functions as a microphone, which makes the incoming sound louder, so that even the few still functional sensory cells are stimulated in the ears of the hearing impaired.

The problem is, however, that a major part of disturbing noises from the environment is equally reinforced and the person concerned is flooded with a veritable barrage of sounds and tones.

But the healthy human ear is much more sophisticated.

"Our auditory system has been so optimized in the course of evolution that it can also filter out or attenuate background noise and therefore we can selectively control the attention," said Ruebsamen.

As the scientists found out, human's hearing system has built a time filter, by which not all of the recorded acoustic signals are passed to the auditory centers in the brain uninhibitedly.

Such knowledge could ultimately serve to develop hearing aids to make life of people with hearing loss in the long term easier, said University of Leipzig. Endit