New Noise-Canceling Windows Will Cut Down The Noise In Big Cities

It is nice to feel the breeze coming through an open window but in a city, there can be a lot of unwanted street noise. A team of researchers at the Nanyang Technological University, Singapore (NTU) have developed a window-based system which can cut noise which is coming from outside. The noise-canceling system not only blocks the sound but also encounters it with its own sound waves. It is inspired by the kind of noise-canceling tech which is used in headphones.

The device uses a microphone through which it can listen to the incoming noise before the algorithms analyze the waveform. After the noise is analyzed, the algorithm generates an inverted version that is then emitted through the speakers. When both sounds converge, the noise coming from outside is dulled and saves the listener from the honks of traffic or the endless hammering coming from the construction sites.

The noise-canceling technology has already been in use in headphones, earplugs, motorbike helmets, cars and in the anti-snoring devices. NTU team has worked on the technology to bring it to windows as well. The prototype system is made up of a grid of devices. Each of it contains a microphone, a speaker, and a processing unit. It can be fitted over a window grille. The active array is capable of detecting noise before it reaches the window and processes the sound in real time.

Gan Woon Seng, lead researcher on the project said, “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. 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.” The team also built a replica room to test the system. The room had windows and doors inside a soundproof chamber. The prototype was attached to the window. To emulate outside noise, The speaker was set to play recorded sounds like construction work and passing planes, trains, and automobiles. The researchers claimed that it managed to reduce the noise by almost 50%.

The system cuts the noise pollution coming from your window but it does add to visual pollution. The team says that reducing the bulk from the window is another goal of further work. It also improves cost and noise-canceling efficiency. Gan said, “We are currently finding ways to improve the technology further so that it can be used not only at window grilles with large openings, but also provide a cost-effective solution that can be easily installed and replaced. Ultimately, we aim to integrate this technology into window grilles that can help mitigate urban noise pollution conveniently.”