Mention headphones or earphones, and active and passive noise cancellation will pop up at some stage of the discussion. Active noise cancellation - when two sound waves collide, and silence ensues The more high-profile of the two is active noise cancellation, or ANC as it is called by many people. So when you are using headphones with active noise cancellation, the microphones in the headphones hear a wave of sound from outside (sound . Passive noise cancellation/ noise isolation — seal the noise out You do not have to get into complex wave production (and relatively high expense) to keep external sounds out from your headphones. This process of keeping noise at bay is called passive noise cancellation or noise isolation—unlike ANC, it does not have a geeky abbreviation, but it remains effective nevertheless.

Source: Huffington Post October 19, 2019 05:48 UTC