If I recall correctly the maximum Noise Reduction Rating (NRR) for earplugs and earmuffs is around 30db. You can combine the two for a slight increase in hearing protection but you still hit a limit because of bone vibration.
Is there PPE out there to go even further beyond this? Where would it be commonly used?
That’s just not true.
Your ear largely hears things through changes in air pressure. Projecting the same frequency and amplitude at the opposite phase prevents the change in air pressure in the first place. It’s literally cancelling the sound.
If you had loudspeakers on the outside of your head, and passive attenuation in your ears, yes that would reduce pressure for you, but everyone else would have experience an increase. But adding more pressure in the cavity of your ear to reduce pressure makes very little sense.
You’re so wrong about this. ANC pretty much eliminates pressure inside the ear canal. That’s how ANC works. No pressure waves, no sound, no damage.
You’re not adding more pressure anywhere; you’re cancelling that pressure out.
Except that’s exactly how nose canceling ear phones work. It’s not like they have an external speaker projecting sound 🤦🏼♂️