That video creeped me out! Now I'm going to be paranoid when I go outside...
Four things I think it could be... 1) it could be the trumpets (of the apocalypse) or 2) (I hate to be all NIN fan about it) it could be the Presence (although it's not showing up visually yet) or 3) Massive shifts in atmospheric pressure change in high altitude or 4) Government(s) conspiracy.
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I thought I could hear children laughing in the Conklin, Alberta Canada clip.