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?

  • Fyde
    3•7 months ago

    I don’t know the exact frequencies but it’s something I read and noticed myself, and wikipedia seems to agree.

    Active noise cancelling is best suited for low frequencies. For higher frequencies, the spacing requirements for free space and zone of silence techniques become prohibitive.

    (Don’t know what that means.)

    Personally I used the Sony XM3 a lot, on planes etc. which have great ANC, and I also used the Moondrop Blessing 3 which are just normal IEMs with no ANC and I only notice a difference in the low frequencies, you can also see that in the rtings measurements (XM3, Blessing 3), isolation in mids and treble is about the same, they seem to consider anything under around 250Hz as bass.

    • @[email protected]
      1•7 months ago

      Yea, that “low frequencies” is rather ambiguous.

      I could see over-the-ear headphones being better at “lower” frequencies than in-ear, both from material absorption and speaker size. Every ANC pair I’ve had, of any style, was pretty good at nearly eliminating the higher frequency noise while flying (engines, airflow noise, etc), and almost eliminated voices.