How do noise-cancelling headphones work?CNET explains the tech behind noise-cancelling headphones, which electronically eliminate the sounds of your surroundings.
Noise cancelling headphones mean you can chill out with your music without annoying external sounds intruding on your listening pleasure. How does noise cancelling technology work? To begin with, all headphones cancel out noise to some degree. But when we talk about noise cancelling headphones we usually mean active noise cancelling which electronically removes the noise of your surrounding. Here's how it works. All sound is transmitted in waves, described in terms of amplitude, wavelength, and frequency. Noise cancelling headphones effectively erase external sounds by using a microphone hidden in the headphones that listens to surrounding noise, then generates a sound wave that's out of phase. Which means it has the opposite shape and feeds that into your ears. The two waves cancel out in a process called destructive interference which sees the wave generated by the headphones effectively acting as a sound eraser resulting in you hearing less of the outside world. This sound erasing tech can also be found in some cars and is being suggested it could one day keep the inside of your house quiet. Although the tech has been around for a while now, however, you'll still most likely to come across active noise cancellation in headphones. These high-tech headphones aren't perfect. They don't eliminate all noise and some people complain that they can hear the hiss of the noise cancelling tech which is annoying in itself. You also need to find some way of powering that extra technology so many noise cancelling headphones require batteries. Still, if you travel a lot on planes and trains this cleaver sound [INAUDIBLE] technology could make for a happier,more relaxed audio experience.