Outside street noise can be disruptive to homeowners. That's why, inspired by noise-canceling headphones, researchers at Nanyang Technological University, Singapore (NTU) have developed a window-based system that can actively cut noise coming from outside.
New Atlas writer Michael Irving says that the technology doesn't just block sound, but actively counters it with its own sound waves, allowing it to deaden the noise of cars, honking, or construction.
The prototype system is made up of a grid of devices that each contain a microphone, a speaker and a processing unit. Fitting over a window grille, this active array is able to detect noise before it reaches the window, and process the sound in real-time.
"Compared to noise cancellation headphones, what we have achieved is far more technically challenging as we needed to control the noise in a large open area, instead of just around the ear," says Gan Woon Seng, lead researcher on the project. "Our innovation not only computes the right amount and type of 'anti-noise' to emit, but also does it faster than the detected noise can reach inside the building."
To test the system, the team built a replica room, complete with windows and doors, inside a soundproof chamber. The prototype was attached to the window, and to emulate outside noise, a speaker was set up to play recorded sounds like construction work and passing planes, trains and automobiles. The researchers say it managed to reduce the noise by up to 50 percent.Read More