There is a weird one. The people don't sound like hoaxers to me at all. Not a trumpet sound but like continuous thunder or machinery that keeps a constant level of sound. The video is 9 minutes not 20. Pretty much the same all the way through until the end when there is a very bright flash in the sky and the noise just tapers off to nothing in a few seconds.
The lady calls 911 and they tell her a number of people had called. They also say the news carried a story about it and the weather service tried to explain it. But they didn't buy that. Once you get the gist of the video you might want to skip to about the 7:20 mark and watch to the end from there.
Thanks - weird stuff.
http://poleshift.ning.com/profiles/blogs/ukraine-strange-sound-in-kiev
Here is I guess a “famous” one from Kiev - Ukraine. Interesting how there is no response from the pedestrians far below. And the camera operator also thinks it is odd I think and is why she zooms in on them.
After she zooms in on them a window in the opposite building opens, and looks like a couple of people come to the window.
It would be interesting to understand what the little kid is saying to the operator (a woman).
And this one does sound like large machinery grinding against each other, slowly. But obviously way too loud so high up in the air.
According to the people in your video, they live only 3 miles away from the airport. I suspect the noise they were listening to was that of an airliner(s) waiting for take off until the end when it decided to shut off the engines.
The corresponding flash was probably just a coincidental flash of lightening, probably an off shore or inland storm......that's the best I can come up with...