Comments by "EebstertheGreat" (@EebstertheGreat) on "A Robot That Walks, Flies, Skateboards, Slacklines" video.

  1.  @griseld  Not really. Active noise cancellation works by generating a sound identical to but 180 degrees out of phase with the ambient noise. That will only cancel right at the source of the noise cancelling speaker, where the two waves destructively interfere. As you walk away from the speakers, they will interfere differently, and the noise can even get louder. Now, if you have multiple noise-cancelling speakers and fixed acoustic properties, like in some cars, you can create decent noise cancellation at many different points (e.g. near the top of each seat, where people's heads will be), but if you change anything in the car (e.g. move a seat), it won't work anymore. Maybe some day we will be able to constantly generate acoustic maps of the surroundings in real time using ultrasound and have sophisticated noise-cancelling speakers on the drone itself or something, but we are nowhere near that point right now.
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