Active noise cancellation uses a variety of techniques and technologies to quiet the sound of the engine and other loud noises in the cabin of the vehicle. This is meant to improve the driving experience for drivers and passengers and also allows auto makers to increase the sounds of certain desirable noises.
Most active noise cancellation relies on microphones placed around the cabin. These microphones pick up certain frequencies that are relayed to the Active Noise Cancellation unit, which then creates a reversed signal that cancels out the frequency of the normal cabin noises.
So basically, it doesn’t make it so there’s less noise inside the cabin—it just makes it so our ears can’t hear the sound, giving the illusion of a quieter cabin. And the ANC unit targets low frequency noises like the drone of the engine, so you don’t have to worry about not being able to hear concerning noises like squealing brakes.