We sell high quality noise cancellation headphones such as the AKG K28NC and the very affordable JVC HA-NC80, JVC HA-NC100 and Panasonic noise reduction headphones.  Our consumer products department selected these headphones.  They have received excellent reviews by professional critics.  The two types of noise cancellation technology are passive cancellation and active noise cancellation.  Passive cancellation is achieved through the manufacture’s use of noise dampening insulation.  These headphones are used where ambient background noise is not a problem.  The majority of headphones sold incorporate passive noise cancellation.  The noise cancellation headphones we sell employ active noise cancellation technology.  Simply put, both left and right headphone speakers have their own microphones and electronics that create inaudible noise reduction sound waves that eliminate ambient background noise.  The headphone electronics operate on their own battery to avoid using power from portable music players.  This process actively blocks 70% of ambient background noise to maximize your music enjoyment.  If you desire more information on active noise cancellation technology check out this link:  http://en.wikipedia.org/wiki/Active_noise_control