Researchers at Hong Kong University of Science and Technology have discovered a method that allows them to filter out almost all the noise in a given environment — no matter how loud or quiet it is.

Many asymmetric absorbers are currently based on a single-port system, where sound enters one side and is absorbed before a rigid wall. In this design, however, light and air are unable to pass ...

Normally, one must choose between sound absorption and diffusion. However, researchers have designed a metamaterial that combines both functions in the form of an acoustic panel. Published in the ...