Comments by "Mikko Rantalainen" (@MikkoRantalainen) on "WHAT are those SOUNDS on American Airlines AIRCRAFT?!" video.

  1. If there's an active noise cancellation system, a broken microphone of such system combined with the noice cancellation system might be a possible solution. If this re-occurs often enough, creating a multi-microphone recording of the cabin would allow pinpointing the source of the audio. I'd expect it to be the PA system, but in case this is some kind of prank, it could be some kind of portable speaker somewhere in the cabin, too.
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