The system is based on microphones that “listen” to the sounds outside and inside of the earphone, an ANC chipset inverting the soundwaves and a speaker inside the earphone cancelling the outside sound by the neutralising soundwaves. A bit like taking +2 outside and adding -2 inside to make zero.
Active noise cancellation can be processed through the ANC chipset using either:
- a feed-forward ANC system has a microphone which is placed on the outside of the earphone
- a feed-back ANC system has a microphone which is placed on the inside of the earphone
- a hybrid ANC system is a combination of a feed-forward and a feed-back ANC system