The world is getting louder and louder and all that noise poses a health risk, especially for people in urban settings. According to the EPA, noise pollution can lead to hearing loss, stress, high blood pressure, and trouble sleeping, among a host of other ailments.
With that in mind, scientists are searching for better sound-absorbing materials to help us insulate ourselves from an increasingly noisy world. A new study published in Proceedings of the Royal Society A did not look to engineering, but to nature – specifically moths – for inspiration.
The world of moths isn’t necessarily particularly noisy, but there are certain sounds they prefer not to hear and when they do, they want to absorb as much of them as possible. Bats, one of the main predators of moths, use echolocation to emit sound waves at prey and get closer to their location. Finding effective ways to prevent this signal from returning to a bat is literally a matter of life and death.
To test the sound-absorbing qualities of moth wings, scientists covered metal discs with pieces of moth wings and bounced sound off of them. They found that the wings absorbed up to 87% of sound waves by vibrating small scales on their surface.
Their sound absorption capabilities are about ten times greater than anything humans have been able to conceive of and could inspire the creation of sound absorbing wallpapers.