http://www.noisefreeheadphones.com. Sony’s MDRNC22B headphones offer external noise reduction up to 75% making them an ideal choice for travelers, commuters and almost everyone who wants to listen to their music in peace. They are equipped with special noise-cancellation circuitry which first senses an ambient signal and then generates a reverse signal with equal strength to cancel out its effect. The neodymium magnets give you crystal-clear sound with sharp bass and rich trebles.