DESC: Whether used to Block out Sound while on an aircraft or to create a tranquil environment so you can enjoy your favorite CD track, these new Headphones are up to the challenge. The new RP-HC300 noise canceling headphones are designed to reduce background noise by creating out-of-phase sounds that equal the background noise to effectively cancel it. Additionally, the headphones reduce low frequencies such as the drone of a plane's engine or a loud air conditioning unit. The noise-canceling feature can also be switched off to allow the User to converse or to reduce background noise by virtue of the headphone's comfortable insulated housing.