Noise cancelling headphones insulate from environmental / ambient noise using 'active' battery-powered electronics
Noise cancelling [NC] headphones employ miniaturized built-in microphones within the earpieces to sense the environmental ambient noise around the headphones via an 'active' (battery powered) electronic circuit. In short, noise-canceling circuitry amplifies and inverts the environmental ambient noise signals, then reverse-adds it back into the music signal to 'cancel' the acoustic noise pressure present at the earpiece drivers. HeadRoom offers a few noise-cancelling headphones, some at a great value including models from Audio Technica, Polk, AKG, Phiaton, and Sennheiser.
Noise cancelling headphones are principally designed to block airline and/or train cabin noise during travel and typically will isolate better than a basic closed headphone in these specific situations, but not as well as in ear headphones for listeners seeking maximum noise-blocking ability.
For more information about 'active' noise cancelling headphones see our HeadRoom noise cancelling selection guide.