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I'm Christopher Intagata.

Restaurants, schools, Dennis Office,

they're all keeping more windows open to increase ventilation

and hopefully decrease the chances of encountering the coronavirus.

But letting in fresh air also lets in more noise.

Now researchers have come up with a device that's like noise-cancelling headphones,

but for a building.

It works on the same principle, so it detects noise that's coming into the windows and then it's cancelling the noise.

Bon Lame, an acoustical engineer at Nagnon Technological University in Singapore.

The device looks like a grid of small speakers and fits over an open window. A microphone samples

incoming noise and then sends the speaker grid instructions on what sort of

anti noise to emit. The result is to cancel out the incoming sound.

For example, here's the sound of a commuter train in Singapore

with no noise control.

And now here's that same sound with the array of noise cancelling speakers turned on.

Compare that to a closed window.

The anti-noise device is almost as good and it allows air to keep flowing into and out of the window.

The details are in the journal Scientific Reports.

The device is just a prototype, so it's still expensive, and it doesn't block out all sounds. It only masks sound at frequencies from 300 to 1,000 hurts, which includes the rumble of freeways, trains and planes.

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