I watched some videos of these after I heard about them. Some people in the comments mentioned the exact same noises in different parts of the world, such as birds singing the same tune. Now that's a massive coincidence, no? I'd call fake. I mean, noises like that would have world wide news coverage, yet I heard nothing about them on the news, just on the internet, some people doing a massive troll most likely. If you watch a couple vids you can hear the same noises in different parts of the world. Also, it only seems to be the camera people who hear them and everyone else goes on like a normal day. Weir, huh?