Cricket-like sound detector gives hope for deaf

From: Telegraph.co.uk - London,England,UK - Jun 20, 2005

Super-sensitive sound detectors used by crickets to spot predators have been recreated in the laboratory.

Scientists hope studying the tiny artificial hairs might lead to the development of new cochlea implants for the deaf.

Crickets' sound detectors are providing hope for better hearing aids Some species of crickets have developed a pair of hairy appendages on their abdomens called cerci, which can detect the smallest fluctuations in air currents.

Each of the hairs is lodged in a socket. Air vibrations drag on the hair, rotating its base and triggering specific nerve cells. The nerve messages allow the cricket to pinpoint low-frequency sound from any direction with incredible sensitivity.

Physicists at the University of Twente in the Netherlands built their own version of the system with up to a few hundred artificial hairs, the Journal of Micromechanics and Microengineering reported.

The fine plastic hairs are attached to membranes with built-in electrodes and capacitors.

Airflow on the hair causes an electrical change which sends out a signal in a similar fashion to the cricket's cerci.

In the more distant future the scientists hope the structures might lead to more sophisticated and efficient cochlea implants.

Hearing is made possible by tiny hairs disturbed by liquid in the cochlea of the inner ear.

If the sensitive hairs are destroyed they cannot send out nerve messages in response to sound, and deafness results.

© Copyright of Telegraph Group Limited 2005.