5 Most Mysterious Sounds Ever Recorded

52 Hertz Whale

Often described as the world’s loneliest whale, the 52-hertz whale calls out at frequency of 52 hertz a much higher frequency than the vocalizations of the most other whales. Scientists are certain that the sonic signature is that of a whale, but the exact species remains a mystery. While the whale’s movement patterns match no known species, certain characteristics have lead to speculations that it may be a blue whale hybrid.

First detected in 1989, the solitary whale continues to be heard every year and remains the only one of its kind.