I know about destructive interference in theory, but was always curious about the perceptual vs real SPL.
Whenever I’ve tried ANC (Bose) it’s always hurt my ears, even when quiet.
ANC is more for comfort than safety from what I understand.
Apple does market 'Hearing Protection' as a feature of the AirPods Pro. https://support.apple.com/en-us/120850
> The Hearing Protection feature is not suitable for protection against extremely loud impulse sounds, such as gunfire, fireworks, or jackhammers, or against sustained sounds louder than 110 dBA.
I suppose if you know your tools operate at 110 dBA or lower levels, you're good to go. The feedback is bizarre though... Hopefully Apple resolves that with a firmware update!
Edit: It looks like it can safely attenuate sound at 110 dBA for 16 to 63 hours. That's impressive!
Closed headphones or foam ear plugs would be better than earbuds with ANC. People have tried to create informal amateur NRR ratings for many consumer headphones, but since it's your only pair of ears in my opinion it makes sense to go for officially rated hearing protection.
If you have sensitive ears you can tell ANC works by playing audio and that it's far from perfect. In very loud environments there's also the risk that a damaged earbud will squeal or feedback, disabling noise protection and exposing your ear to the full brunt of the loud noise.
I tried them for several weeks, everyday and ended up with annoying ear infections. Also they are quite uncomfortable to wear when sleeping.
I can say I've used ANC in-ear and over-ear of various implementations for years without experiencing discomfort typically associated with ANC 'pressure'.