An insect-inspired microphone that can tackle the problem of locating sounds and eliminate background noise is set to revolutionise modern-day hearing aid systems.Despite remarkable advances in sound analysis in hearing aids, the actual microphone itself has remained essentially unchanged for decades.
The engineers, from the Cockrell School of Engineering at the University of Texas at Austin, say the new device could be used in a new generation of hypersensitive hearing aids that use intelligent microphones to select only those sounds or conversations that the wearer wants to hear.
Using the fly's super-evolved hearing structure as a model, Prof. Hall and colleagues made a tiny pressure-sensing device out of silicon. With a span of only 2 mm, the device is nearly the same size as the fly's hearing organ.Unlike many insects, the reason humans and other mammals can pinpoint the source of a sound is because we have a much larger distance between our ears. The sound processing mechanism in our brains uses the time difference in the arrival of the sound at the two ears to locate the source.
A cochlear organ for frequency selectivity was thought to be unique to hearing in mammals until Dr Montealegre-Z led the team that discovered a similar mechanism for frequency analysis in the ears of bushcrickets in South American rainforests two years ago.Scientists believe the discovery of this previously unidentified hearing organ could pave the way for technological advancements in bio-inspired acoustic sensors, including hearing aids.
