Inaudibility Cloak Being Developed

December 29, 2011 Updated: September 29, 2015

Want to play music at night without bothering neighbors? Being annoyed by noises from the highway? Scientists at Germany’s Karlsruhe Institute of Technology (KIT) can help.

Inspired by the concept of an invisibility cloak that guides light waves around an object making it invisible, the researchers are developing a cloaking device that can render objects completely silent. This device uses a custom-engineered plastic material that guides sound waves around an object making it inaudible.

The material has a smart microstructure consisting of two polymers, one soft and one hard, which form a millimeter-thin plate. Sound waves are guided around a circular area in the plastic plate in such a way that vibrations can neither enter nor leave this area.

“Contrary to other known noise protection measures, the sound waves are neither absorbed nor reflected,” researcher Martin Wegener said in a press release. “It is as if nothing was there.”

The technology is presently only a proof of concept, but when mature, it could be effective at soundproofing and have a wide range of applications.

The study will be published in the journal Physical Review Letters.