How noise cancelling actually works

Active noise cancelling listens before you do. Small microphones on the outside of each cup hear the world, and a chip builds a mirror-image wave that cancels it before it reaches your ear.

It works best on steady, low sounds: engines, air-conditioning, the hum of a train. Sudden, high sounds such as voices are harder, which is why the cushions matter just as much. A good seal does the passive half of the work.

Our adaptive mode re-tunes this mirror wave many times a second, so a quiet office and a loud platform each get their own correction.