How Insects Inspired New Hearing Aid Microphones

Researchers are in the midst of developing a new hearing aid with a directional microphone designed to eliminate unwanted background noise -- similar to the ear of an insect.

Kristopher Sturgis

Mussel- and gecko-inspired adhesives, artificial blood vessels made of spider silk, cuttlefish-inspired ingestible sensors... There have been plenty of research breakthroughs over the years that have been inspired by nature. Researchers from Glasgow decided to run with the same approach when developing hearing aid technology--by looking to insects. The resulting microphone technology helps locate specific sounds while eliminating background noise picked up by directional microphones.

Microphone technology has progressed slowly, remaining largely unchanged for decades. Current directional microphone technology often adds weight and power requirements that drive up the cost of production.

James Windmill, PhD, one of the lead researchers on the new hearing aid system, spoke about the genesis of the idea and how the new hearing aid system can improve current technologies.

"The idea of taking inspiration from insect ears has been around since the 1990's," Windmill explains. "I've been exploring insect hearing and looking at what we can learn from it. At Strathclyde, we have tried not to mimic the insect ear, but rather take the basics of how the insect ear works. We then looked at different things based on them. In particular, there are specific characteristics that we are interested in to make the technology practical for humans."

Windmill says that current hearing aid technologies excel at audibility, but are only partially successful at providing intelligibility in noisy situations. With this conventional technology, acoustic directionality is important, so a target sound is ideally located in front of the user.

"A hearing aid currently only gets its directionality -- its ability to attenuate sounds coming from particular directions -- by having two ports or two separate mics spaced approximately 10 millimeters apart," Windmill says. "This new microphone is directional in a singular miniature device, and has the potential to work not just along the axis of the two ports in conventional aids. Therefore, this mic design could finally deliver on what drives people to seek out help, making it a huge step forward in providing hearing assistance.

Many challenges still remain, however, including the development of a directional microphone that is as sensitive to sound as a standard microphone.

"We are getting close to solving that," Windmill says. "This three year project is designed to take our lab based designs and see what we need, to push them toward something that would be useful in a hearing aid. We're not the only ones looking at this sort of technology, but as far as I know, there are no hearing aids with this kind of technology yet."

A fact Windmill and his group are hoping to change as their research progresses. The group remains pretty tight lipped on their plans to advance the technology in the near future, but their objective remains clear. Windmill and his team intend to continue exploring insect hearing in the hopes that with careful research, we can use what we learn to enhance microphone technology in our own hearing systems, all in an effort to help those affected by hearing loss in new innovative ways. 

Kristopher Sturgis is a contributor to Qmed and MPMN.

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