Noise-reducing headphones are now standard. In airplanes, on trains or on the street: in noisy places, more and more people wear noise-reducing earphones to enjoy music undisturbed. Researchers at Nanyang Technological University in Singapore have now investigated whether the technology is also suitable for protecting homes against street noise. The results are interesting.
From headphones to the window
The way noise cancelling technology works is simple. A microphone detects the noise coming from outside and transmits the information to a connected loudspeaker, which generates a signal with reversed polarity. The sound waves coming from the outside are thus opposed in exactly the opposite way, so that the wave crest and wave trough meet. This in turn has the effect of neutralising the sound to a certain extent. This technology works perfectly with headphones, not least because they only have to react to a very limited sound volume.
Nevertheless, researchers at Nanyang...
