What are these sounds captured in Larissa, Greece?

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Some strange sounds were captured in Larissa, Greece. Are these the strange sounds in the sky or just the city noise? This video is definively not fake. There're no signs of...

Strange sound in Kiev, Ukraine, August 2011

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This was one of the earliest records of weird sound all over the world. The sound from this clip was used in numerous fake videos later. This sound was recorded at...