Julia (1999)

The "Julia" sound is a mysterious underwater audio phenomenon recorded by NOAA's equatorial autonomous hydrophone array in 1999. Lasting about 15 seconds, this distinctive sound resembles a human's cooing or whining noise combined with metallic vibrations. Originating from an area near Antarctica, the sound's source remains unidentified, though scientists speculate it may have been caused by the sudden shifting of a massive iceberg or its scraping along the seafloor. Like other unexplained ocean sounds, Julia demonstrates how much remains unknown about deep-sea acoustic phenomena. Its eerie, almost organic quality continues to intrigue both researchers and enthusiasts of ocean mysteries.