Strange Sounds from the sky April 2017 compilation: Noise heard across the globe for nearly a DECADE – but nobody has an explanation

What IS this strange sound from the sky? Noise heard across the globe for nearly a DECADE – but nobody has an explanation.
By Strange Sounds
Here a compilation of the latest strange sounds captured in April 2017 around the world.
 
 
Strange Humming Noise In Racine WI 4-18-17A mysterious noise from the sky is continuing to baffle people all over the world – as well as giving those who hear it sleepless nights.
Strange Noise in the sky again today West Valley College. 18/04/