Airpods Pro are not exclusively reliant on active noise cancellation to reduce noise alone-- the tips seal in your ear canal and provide passive isolation as w

Airpods Pro are not exclusively reliant on active noise cancellation to reduce noise alone-- the tips seal in your ear canal and provide passive isolation as well, similar to how earplugs or conventional IEMs (in-ear monitors) work. AirPods are not rated as earplugs and I wouldn't suggest relying on them alone to prevent hearing damage in loud environments (buy real earplugs for that), but they will provide some reduction in the noise that reaches your ears even when turned off. Also, active noise cancellation does actually cancel noise (it's not some kind of psychological effect making noise "invisible"); sound is a pressure wave and ANC works by moving air in the opposite direction to eliminate or reduce that pressure wave-- the mechanical energy from that sound is not reaching your ear drum if you don't hear it. This doesn't work perfectly, of course (the higher the frequency, the harder it is to eliminate with ANC for a bunch of acoustic and processing-related reasons), but, generally, if you're not hearing it, it's not reaching your eardrums and it's not doing damage.