When I bite my nails while wearing sound cancelling earbuds, I can hear a moment of static as my skull absorbs the sound or whatever. What's going on here? - eviltoast

I assume it has something to do with the sound cancelling. It uses white noise or something, right? I’m running out of nails to test this.

  • TranquilTurbulence@lemmy.zip
    link
    fedilink
    arrow-up
    24
    ·
    edit-2
    2 months ago

    The noise cancelling headphones are listening to noise coming from the outside and cancels them out. When the source of the sound is in your mouth (see also: bone conduction), the headphones can’t hear or cancel that sound.

    The headphones should still cancel the background noise as usual, but they can’t cancel whatever noise is coming from your mouth. I wonder if this mismatch could result in some noise getting through?

    If you’re wearing buds, the seal could become inadequate while your jaw is moving, so that could also explain some of the noise.

    • deranger@sh.itjust.works
      link
      fedilink
      arrow-up
      2
      ·
      edit-2
      2 months ago

      Some headphones now have internal noise cancellation, such as AirPods Pro and Max. I can hear it working when I’m chewing something crunchy or when I’m using my electric toothbrush and toggling between transparency and NC modes. Kinda curious if some other cans have this as well, it’s a nice feature. There are microphones inside the cup listening to internal sounds and cancelling those out as well as external sounds.

      • TranquilTurbulence@lemmy.zip
        link
        fedilink
        arrow-up
        1
        ·
        2 months ago

        Theoretically, that could help a little bit, but it won’t change the fact that the ear canal is only the gateway to the organ where hearing actually takes place. Due to bone conduction, the crunchy noises can take a shortcut and bypass the outer ear completely.

        • deranger@sh.itjust.works
          link
          fedilink
          arrow-up
          2
          ·
          edit-2
          2 months ago

          It still works pretty well, not as effective as regular external NC of course, but the difference between transparency and isolation modes when chewing crunchy foods or using my electric toothbrush is very noticeable. Now I’m going to have to do a bit of an experiment with bone conduction headphones from a friend and ANC mode to see how well it’s working.

  • Akasazh@feddit.nl
    link
    fedilink
    arrow-up
    11
    ·
    edit-2
    2 months ago

    A static type sound can occur while biting where you eustachian tubes are cleared. The same thing can happen when yawning (it is why yawning is encouraged when feeling inner ear stress while taking off in an airplane).

    It happens without earbuds too, but might be more noticable.

    I can personally pop those voluntarily, as I’m a scuba diver, and you have to clear your ears quite frequently.

  • jeffw@lemmy.world
    link
    fedilink
    arrow-up
    9
    ·
    edit-2
    2 months ago

    Think of noise as a sine wave on a Cartesian plane (the X-y graph you used in math class). The noise goes up and down so that y=1 at the max and y=-1 at the minimum.

    What happens if we add 1 when y=-1? Well, now it’s 0. And what happens if we add -1 when y=1? It’s 0 again. That’s basically what noise cancelling does. It adds the “opposite” to make the sound equal 0. That’s super layman’s terms, but I hope it makes sense. It’s basically trying to make the opposite of whatever it hears.

    But when something is physically touching your body, your ears can’t absorb that “opposite” sound because the original sound is kind of already absorbed in your body, if that makes sense?

  • Ferris@infosec.pub
    link
    fedilink
    arrow-up
    6
    ·
    2 months ago

    noise cancellation should be better at adjusting for sounds which occur for longer periods of time. it takes time to calculate the inversion, the amplitude, the frequency, the emission and line them up.

    What does popcorn sound like?