Wireless headphones with noise cancellation: the ideal ratio of comfort, sound, and silence. Bose measures, compares, and responds to external noise by using tiny microphones to cancel it out with opposing signals. Bluetooth has a 30-foot (30-meter) range. High-fidelity audio is provided by the depth and fullness of the TriPort acoustic architecture. Volume-optimized Because active EQ keeps the performance balanced at all volume levels, the bass remains steady when the volume is lowered and the music is still audible when it is raised. QUIET AND AWARE MODES: Select Aware Mode to bring the outside world into the around-ear headphones and simultaneously hear your music and surroundings, or Quiet Mode for complete noise cancellation. UP TO 22 HOURS BATTERY LIFE: Take advantage of a battery life of up to 22 hours between charges. A brief 15-minute charging period provides