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?

    • @[email protected]
      11•7 months ago

      ANC isn’t protective in any way. If anything it’s probably just as damaging.

      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.

        • @[email protected]
          7•7 months ago

          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.

        • @[email protected]
          2•7 months ago

          Except that’s exactly how nose canceling ear phones work. It’s not like they have an external speaker projecting sound 🤦🏼‍♂️

          • @[email protected]English
            3•7 months ago

            Except that’s exactly how nose canceling ear phones work.

            Mine work like this: “Got your nose. Neener neener neener.”

            • @[email protected]
              4•7 months ago

              Bro. It’s not “just more pressure.” It’s literally less pressure.

              If there are water waves moving a boat up and down, and you actively apply some movement (ha! pressure!) to the water so you generate waves that cancel the existing ones so that the boat stands still, would you say “but you don’t understand, the boat is getting MORE PRESSURE!!! It’s being damaged!!!”? Of course not. It’s pretty much the same principle.

              Get a highschool physics book, read the chapter about sound, and come back. Otherwise, just stop.

    • Hucklebee
      10•7 months ago

      I know nothing about this subject, but my instinct would tell me that anc would actually be protective. If you phase out sound, it seizes ceases to exist, right? That is the whole point of it?

      Again, pure instincts, don’t know shit myself.

      • @[email protected]
        7•7 months ago

        *ceases, FYI (not being snarky, maybe autoincorrect got you on voice to text)

        Edit: also “seizes” used here was kinda funny

        • Hucklebee
          2•7 months ago

          Thanks for the heads up. Non-native, always willing to learn.

    • @[email protected]
      2•7 months ago

      This is partially correct, partially wrong.

      As many have commented, flipping a signal by 180° cancels it out. However, this is only true for static noise though. Transient noise cannot be canceled out completely, because you would need to see into the future to know which signals to play to cancel out the noise.

      The ANC headphones I own mainly cancel noise through passive shielding of the ears. The “active” noise canceling feature is not contributing a lot.