Noise-canceling robots to ‘mute’ loud conversations in cafe | What if we told you that we can actually silence a noisy table right next to us in a café?::undefined

  • LibertyLizard@slrpnk.net
    link
    fedilink
    English
    arrow-up
    22
    ·
    1 year ago

    Wait, what? Doesn’t phase cancellation actually cancel the waves? How can it be inaudible but still present?

    • vector_zero@lemmy.world
      link
      fedilink
      English
      arrow-up
      24
      ·
      1 year ago

      The waves are canceled (i.e. gone) until something goes wrong. You could end up accidentally causing constructive interference, in which case you my double the sound’s amplitude.

        • br3d@lemmy.world
          link
          fedilink
          English
          arrow-up
          14
          ·
          1 year ago

          Yes - but 3db is twice the energy, which is what matters when it comes to damaging your cochlea

      • LibertyLizard@slrpnk.net
        link
        fedilink
        English
        arrow-up
        2
        ·
        1 year ago

        I feel like this doesn’t happen very often though. I mean I wear sound canceling headphones all the time and I’ve never noticed it accidentally making anything louder. Then again, I don’t normally stand near jet engines.

        • K3zi4@lemmy.world
          link
          fedilink
          English
          arrow-up
          4
          ·
          1 year ago

          I wouldn’t imagine noise cancelling headphones would have the ability to output high enough for serious damage. But some people do experience discomfort and pressure when using noise cancelling headphones for the first time, this could be due to a number of factors though.

    • K3zi4@lemmy.world
      link
      fedilink
      English
      arrow-up
      4
      ·
      1 year ago

      Yes, sorry, I didn’t phrase that well at all. The sound pressure is actually cancelled out, but with the hypothetical example of the jet engine, anything going wrong could double the dB level instead of cancelling, and because we’re talking milliseconds difference, it would be quite easy to go wrong in this sense.