Scientists Say You Can Cancel the Noise but Keep Your Window Open - The New York Times

Researchers in Singapore developed a system that’s sort of like noise-canceling headphones for your whole apartment.

Researchers in Singapore have developed an apparatus that can be placed in a window to reduce incoming sound by 10 decibels.

Borrowing from the same technological principles used in noise-canceling headphones, the team expanded the concept to fit an entire room by placing 24 small speakers in a window.

The speakers emit sound waves that correspond to the incoming racket and neutralize it — or, at least some of it.

With any sound, the best way to reduce it is at the source, like a gun’s silencer.

So the researchers treated the window aperture itself as the noise source, because most noise enters a room that way.

The system uses a microphone outside the window to detect the repeating sound waves of the offending noise source, which is registered by a computer controller.

That in turn deciphers the proper wave frequency needed to neutralize the sound, which is transmitted to the array of speakers on the inside of the window frame.

The speakers then emit the proper “anti” waves, which cancel out the incoming waves, and there you have it: near blissful silence.