The True Adaptive Noise Cancelling technology is a features which adjusts noise-cancelling levels in real-time, 50,000 times per second to account for environmental ambient noises and personal attributes such as movement, hair and eyeglasses to deliver best-in-class Noise Cancelling and immersive sound in any environment.  
With the help of Feed Forward and Feed Backward microphones, the Adaptive Noise Cancelling technology fully monitors exterior sounds picking up low-frequencies and neutralizing them before they reach the ear. The headphones generate a sound that's phase-inverted by 180 degrees to the unwanted noise, resulting in the two sounds cancelling each other out. 
In addition, all headphones allow the listener to adapt or adjust the level of ambient noise through features like Ambient Aware and TalkThru.