Help cancelling noise

[Android Question]

Would noise cancellation headphones cancel noise if not plugged in to anything? I realize this isn't technically an Android question but I figure if anybody would know it would be Android Forums.

 

[Telyx]

No, they work by "listening" to outside noise and "playing it back" 180 degrees out of phase, so if they aren't plugged into anything they would just act like passive earmuffs.

 

[AZgl1500]

@Telyx ^^^^ is correct.

I own a set of Bose Noise Cancelling headphones.... and if they are not powered ON, they are just ear muffs.

However, they do cancel outside noises w/o the cord being plugged into anything at all....
you just need to turn the headphone's power switch on.....
Bose headphones are powered by an internal battery.​