The superb-sounding Altec Lansing AHP712 headphones with Active Noise Reduction are ideal for the frequent traveler and anyone in a noisy environment. Active Noise Reduction technology uses small microphones to â??listenâ? to ambient sounds and special circuitry to create a sound wave 180 degrees out of phase from the ambient sounds. When the sound wave is played through the headphones, it reduces ambient noises, such as airplane engines and subway rumbles, to allow you to focus on your music, movies or games.