Lam said, splaying his hands to denote the calming effect. “If you sit in the room, you get that same feeling like when you flick on the switch of noise-canceling earphones,” Dr. The speakers then emit the proper “anti” waves, which cancel out the incoming waves, and there you have it: near blissful silence. 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 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. So the researchers treated the window aperture itself as the noise source, because most noise enters a room that way. With any sound, the best way to reduce it is at the source, like a gun’s silencer. The Anti-Noise Control Window, as it is called, is the sonic equivalent of shutting a window. Lam explained that “in places like Singapore, we want to keep the windows open as much as possible” to reduce the use of carbon-intensive air-conditioners and to prevent buildup of stale air that can pose health risks for some people.īut with windows open, the constant din from city traffic, trains, jets passing overhead and construction equipment can rattle apartments.
