Active Noise Cancellation (ANC) Explained

Active Noise Cancellation (ANC) is a technology designed to create a sensation of "cancelled noise". It achieves this by generating an "anti-noise" that counteracts the sound waves of ambient noise, creating a cancellation effect. While ANC aims to reduce as much external noise as possible, few headsets provide a completely noiseless experience.

There are three different implementations of ANC: Feedback, Feedforward, and Hybrid. Each comes with its own advantages and disadvantages.

Feedback ANC​

Feedback ANC uses a microphone placed inside the ear cup to pick up the same sounds the listener hears. This allows the ANC to adapt to sudden changes and make effective signal corrections. Feedback ANC works well across a wide range of frequencies and even if the headset is worn unusually.

However, feedback ANC struggles with high-frequency sounds (particularly in the 1000-2000 Hz range). An improper design can lead to noise feedback. Also, the filter microphone being inside the ear cup can result in your music being filtered out.

Feedforward ANC​

Feedforward ANC uses an external microphone to process noise before it reaches the listener. This allows feedforward ANC to handle high-frequency noises better.

However, since it doesn't hear the anti-noise it produces, feedforward ANC lacks self-correction. It also works within a narrower range of frequencies and is more sensitive to external noises like wind due to the external placement of the microphone.

Hybrid ANC​

Hybrid ANC combines feedback and feedforward ANC by using both internal and external microphones. It provides the benefits of both methods without their disadvantages. Hybrid ANC suppresses noise over a broader range, adapts to sudden changes in noise, and isn't sensitive to the placement of the headset.

However, the use of two microphones often results in a higher cost. The technology behind hybrid ANC is more complex and requires more expertise, making it more expensive overall. The retail AirPods Pro, for example, use hybrid ANC, contributing to their high price. This technology is also being replicated in the AirPods clone market. For example, HiCity's newly released v4.5 (featuring the Airoha 1562A chipset) replicates the hybrid ANC effect for a full and authentic noise-canceling experience.