The Technology That Can Keep Noise Out Whilst Windows Are Open

Summer is here and there is the inevitable desire to keep windows open to cool your home.  At the same time however, there is a seemingly inevitable desire for people to have parties long into the night, thus causing inevitable conflict between those who wish to sleep, and those who don’t.

Being able to combine the natural ventilation of an open window with the peace and quiet of a closed one could be bliss for many, and that’s exactly what a team from Singapore’s Nanyang Technological University promise.

The technology is designed to be mounted onto window grills and the researchers claim it can reduce noise from outside by up to 50%.  It achieves this by using ‘active noise control’ technology, which is the kind of thing commonly found in headphones to cancel out external noise.

“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,” the researchers say.

Noise cancellation

The device, which is currently at a prototype stage, uses 8 watts of power, or a similar amount to that used by a small Bluetooth speaker.  An array of units are placed together into a grid-like formation on the window grill to reduce external noise.

It works to detect external noises via a microphone and processing unit, with an ‘anti-noise’ emitted that uses the same waveform characteristics as the invading noise, except it’s inverted.  This means that when it and the actual noise converge, they cancel each other out.

“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 researchers say.

The device was tested in a soundproof chamber that was designed to replicate the kind of rooms found in the average home.  Various sounds were then projected at the window, including construction noises, jet engines and trains, although as far as I’m aware, no neighboring parties were tested.

After this initial test, the team plan to improve the noise cancellation efficiency whilst also making the device smaller and more cost-effective to hopefully make them ready for market.

“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,” they conclude.

Check out the video below to learn more about the project.