Slow Down (1997)

The "Slow Down" sound, detected by NOAA's autonomous hydrophones in 1997, remains one of the ocean's most perplexing acoustic mysteries. This ultra-low frequency sound gained its name from its distinctive descending pitch over seven minutes, resembling a slow engine braking. Originating near Antarctica's Pacific region, the sound's source has never been identified, though theories range from shifting icebergs to undiscovered marine life. Unlike artificial noises, its organic waveform pattern and remote location continue to baffle scientists. The "Slow Down" stands among several unexplained aquatic sounds that highlight how little we understand about deep-sea acoustic phenomena.