What is noise cancellation for headphones? What does it do?
I work with electronics, and I haven’t really worked with noise cancelling headphones before. But, if I had to guess, I’d say the headphones have small microphones on the outside which connect to a circuit inside that cancels the surrounding sound by producing the outside sound in your headphones, but 180 degrees out of phase. What that basically means is that, your headphones reproduce the opposite sound of the surrounding environment which has a cancelling effect inside the headphones. So, that way, you don’t hear anything except the music.