A group of researchers from the Binghamton University have built a microphone which has been modelled according to a fly’s ears. This new microphone can give a cleaner output and has better acoustical performance as a hearing aid than the existing ones.
The fly named Ormia ochracea has ears which can hear as well as us and has great eardrums that sense sound pressure, inspired scientists to design a device with a microelectromechanical microphone with a 1mm by 3mm diaphragm that rotates around a pivot in response to varying sound pressure.
In order to minimise the feedback that could take place as an effect of the resonance, the scientists used an electronic feedback control system that uses electronic damping known as Q control. The scientists achieved a very low noise floor (the quietest sound to be heard without the signal disappearing in the microphone’s own noise) by electronic damping and thus let the diaphragm resonate at its natural frequency so that no feedback is heard.
The noise floor of the new microphone is 17 decibels lower than a pair of low-noise hearing aid microphones, thus making this device a better option by far as a hearing aid, as it would hear clearly without adding to the noise or sound. Other applications can be in cellphones, surveillance and noise control devices and as an added advantage, it can be made as small as a fly’s ear, say the scientists.