10 Mysterious Unexplained Sounds
Throughout history scientists have been stumped by weird sounds creaking from all corners of the Earth. Still a mystery to science, AllTime 10s brings you the top 10 unexplained sounds.
In physics, sound is a vibration that propagates as a typically audible mechanical wave of pressure and displacement, through a medium such as air or water. In physiology and psychology, sound is the reception of such waves and their perception by the brain. (source : wikipedia