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 ...

Researchers describe an acoustic meta-surface that uses pingpong balls, with small holes punctured in each, as Helmholtz resonators to create inexpensive but effective low-frequency sound insulation.

Long-term exposure to low-frequency noise can cause numerous health problems, but the solution may be found in an unexpected object, a pingpong ball. Conventionally thought of as the hollow plastic ...