How Spider Silk Could Inspire Microphones of the Future and Revolutionize Sound Design

Humans aren’t very good listeners. Not compared to some spiders, anyway.

Orb-weaver spiders don’t have ears, but in 2022, researchers found the arachnids use their webs as external eardrums. The spider silk acts as a super-sensitive listening device, capable of detecting noises from up to ten feet away, according to the research led by Ron Miles, a mechanical engineer at Binghamton University.

At meetings of the Acoustical Society of America last week, Miles said this knowledge of spiders presents a big opportunity for humans to revolutionize our own sound engineering.

The human experience of hearing is dictated by air pressure in our ears. In response to pressure changes, our eardrums vibrate at different frequencies that send electrical signals to our brains, which distinguish and register the sounds. Microphones were built to mimic human eardrums, similarly vibrating in response to pressure changes.

But to make microphones more powerful and sensitive, they need to be larger—a reality that’s incompatible with the general desire for smaller and more transportable technology.

“Humans, being arrogant animals, fashioned the microphone after their own ears—but that’s not necessarily the best way to do it,” Miles tells Scientific American’s Elizabeth Anne Brown. “If you want to make something small, you should think about how small animals do it.”

Spiderwebs are less affected by changes in air pressure. Instead, they vibrate in the airflow created by a sound wave, allowing the arachnids to “hear” by feeling that motion—and even pinpoint the direction of the noise.

Using the orb webs of bridge spiders on the Binghamton University campus, Miles and Jian Zhou, who is also a mechanical engineer at the university, led tests of their sensitivities. They measured how the webs moved with a laser vibrometer and found that spider silk registered sounds between 1 hertz and 50 kilohertz—a much wider range than the 20 hertz to 20 kilohertz that humans can hear.

By applying this sort of acoustic system to a microphone, “you can make it quite a bit smaller without paying a price,” Miles tells the New York Times’ Jordan Pearson.

New Study Shows Spiders Use Webs to Extend Their Hearing

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Miles has developed and tested a microphone based on spiderweb acoustics, which he built with Zhou and Junpeng Lai, a postdoctoral researcher at the university. Rather than using actual spider silk, the tool uses silicon to detect changes in air flow. While still in its early stages, the device’s patent has already been commercialized by a Canadian company called Soundskrit, which is working with Miles.

“Because spider silk is, of course, created by spiders, it isn’t practical to incorporate it into the billions of microphones that are made each year,” Miles says in an Acoustical Society of America statement. “It does, however, teach us a lot about what mechanical properties are desirable in a microphone and may inspire entirely new designs.”

The research presents a jumping-off point for a variety of advances in sound technology. Miles and others are working to develop new instruments that can register extremely quiet sounds emitted by the human ear, which might help detect and treat hearing problems in infants, reports the New York Times. And spider silk-inspired acoustic systems may enable researchers to pick up on other sounds outside the human ear’s range—such as low-frequency noises that precede the formation of tornadoes, which scientists can use to predict and track the storms.

Spider silk’s chemistry and strength have already helped spark developments in body armor and shown promise for promoting nerve regeneration when implanted in animals.

“We’re so used to this marvel in day-to-day life that we don’t question it,” Fritz Vollrath, an evolutionary biologist at the University of Oxford in England who was not involved with the new research, tells Scientific American. “When you start studying it, you begin to realize how amazingly sophisticated the web really is.”

Christian Thorsberg | READ MORE

Christian Thorsberg is an environmental writer and photographer from Chicago. His work, which often centers on freshwater issues, climate change and subsistence, has appeared in Circle of Blue, Sierra magazine, Discover magazine and Alaska Sporting Journal.