ANC works by canceling out the noise picked up by the external microphones with anti-noise (sound waves with the same amplitude but with the opposite phase) generated after analyzing the external noise. A mathematical equation that explains it in a simpler way is by adding -2 and +2. The answer is zero. When likened to active noise cancelation, the generated noise cancels out the external noise.
Apple has announced five different AirPods since the line of earphones first made their debut in 2016. However, the first AirPods to have Active Noise Cancellation didn't arrive until 2019. That year, Apple launched two models – the AirPods 2 and the AirPods Pro, but only the latter had support for Active Noise Cancellation. Not only did the AirPods Pro allow users to block out noise, but it also gave them the option to let in outside sound at any time, thanks to a feature called Transparency mode.
The next pair of AirPods to launch with ANC were the 2020 AirPods Max. While they aren't earbuds, they still fall under the AirPods line. The AirPods Max are Apple's answer to premium noise-canceling headphones from brands such as Bose and Sony. They have noise cancellation and a Transparency mode like the AirPods Pro. The AirPods 3 launched in 2021 don't have active noise cancellation, but they do have a microphone in each earbud that reduces wind noise when users are on a call.
While both the AirPods Pro and AirPods Max have ANC, the experience is better on the latter. This is the result of the AirPods Max having more microphones. The wireless headphones have six outward-facing microphones for detecting environmental noise and two inward-facing microphones to pick up unwanted sound from inside the ears. On the other hand, the AirPods Pro have just one outward-facing microphone and one inward-facing microphone per earbud. In summary, the more the number of microphones picking up sounds, the better the earphones at canceling noise.
Apple is expected to launch the AirPods Pro 2 this year, and like their predecessor, they should have Active Noise Cancellation, most likely with improvements. There are no confirmed reports about the AirPods Max getting a refresh this year but there are rumors Apple will launch new colors. Considering the AirPods Pro are getting a successor after three years, one can presume the AirPods Max will be refreshed in 2023.