ANC is often featured alongside ENC in blogs and videos about earphones and microphones, but ANC and ENC are not the same thing.
Active Noise Cancellation (ANC) works by using a microphone to pick up external sounds and then creating opposing sound waves to cancel unwanted noise. Just like a superhero has special powers to defeat his enemies. ANC is most effective at canceling out low-frequency sounds, such as the hum of an airplane engine or the rumble of a train.