Noise cancelling technology used in open windows

University researchers created an anti-noise device that prevents external noise pollution from entering a room, even if the windows are open.

Noise is inevitable in open plan offices, especially as increased numbers of citizens become city dwellers. Simultaneously, noise pollution has come to be recognised as a health hazard. Innovations such as an app that reviews restaurants, theatres and other public places based on noise level are trying to tackle the problem. Additionally, in Ukraine, several workspaces are testing a prototype of a noise-cancelling helmet-type device.

Taking such noise-cancelling technology to the next level of scale is a solution from Singapore’s Nanyang Technological University (NTU). Designed by researchers in the Centre for Infocomm Technology, the device attaches to the grille of a window and works in a way similar to that of noise-cancelling headphones, but on a much larger scale. A small, eight-watt speaker that is connected to a processing unit creates anti-noise signals that match the incoming noise. When the two waves of sound meet, they cancel each other out. Most importantly, the device works even when windows are open using a microphone to identify external noise. Early tests show that the device is capable of reducing noise pollution by up to 50 percent. Sounds that were studied include construction, trains, roads and jet engines. The team is focusing development of the device on reducing its size, improving its effectiveness and mass production.