Built to track enemy submarines, the Navy’s underwater listening network inadvertently revealed that whales may be singing across entire oceans
9:39 AM CDT on June 4, 2026
In the 1950s, after having endured relentless attacks by German U-boats during World War II, the U.S. Navy devoted considerable resources to detecting and tracking submarines at long range. Chief in this Cold War-era effort was the Office of Naval Research’s creation of the Sound Surveillance System (SOSUS), a complex array of hydrophones fixed on the ocean floor and connected by cables to secret listening stations set up along coasts all over the world.
Through SOSUS, the Navy was able to hear a lot of things: what kind of submarines were out there, how many propellers they had, whether they were conventional or nuclear, and sometimes even the exact make and model number.
But they also heard many other sounds — noises that were of less interest to them. Deep booms, grunts, howls, squeals, clicks, moans. Often, they heard monotonously repeating ultra-low-frequency tones that didn’t come from any machine they could find in their secret catalogs. What, they wondered, could be making them?
