#37: Sounds from Out of this World
This conspiracy tells of a strange happening in Minnesota that many people attest to. They claim to hear a low humming sound that comes from the sky. The sound is so sinister that many people believe that extraterrestrial beings are the source. Note to self: Never go to Minnesota again!

provided by constative.com
As of now, there is no scientific explanation for why this phenomenon occurs, but it could simply be a scenario in which people are following the crowd or want to believe they are part of something big, like an alien encounter. Still, a commonly heard humming sound is not nearly enough to support such a bold claim.