If you live in an urban area, car horns, sirens, and drills are part of your local (and probably unwelcome) 'soundscape', but a new window-mounted device could create peacefully quiet city living.
The device uses a microphone to detect incoming noises and an array of 24 small speakers to cancel out the incoming sound waves. The researchers tested the device with simulated city noises, like airplane engines, and found that the device offered a 10dB reduction in the sound pressure level, meaning about half the noise level reached the indoors.
So how does it work? The device uses “anti-noise” speakers to create sound waves with the opposite wave pattern to the incoming noise. Its use is effectively like putting noise-canceling headphones on your home. The design is not perfected yet. It is less effective in reducing low and high pitch sounds but is ideally suited for noises between 500 and 1,000 hertz, like traffic and trains.
The team plans to begin testing the system in real-world applications soon and estimates it will be ready for large-scale production in the next five to ten years. In addition to filtering out the noise, the device allows residents to leave the windows open, reducing the need for air conditioning without the nuisance of direct city sounds.
Although you won’t be able to buy one for yourself for a while, the new device is an innovative solution to reducing energy use and eliminating one of the biggest complaints about living in a big city.