Who said headphones can't have features?

The Sony MDR-NC500D headphones are not lacking for features. Examining the right earcup reveals several of them. Here, there's an audio input analysis key, a monitor button for muting playback, and a switch for turning the headphones on, which automatically activates the noise-cancellation function, as well. These cans cannot be used without this function, which is a bit of a bummer if your battery runs out.