About 52 Hz
A research paper published in late 2004 shared the strange (and true) story of a hybrid blue whale known as the Loneliest Whale. The movements and beautiful song of this unique creature were monitored during a 12-year period by a vast network of Cold War era sonar equipment scattered about the floor of the Pacific ocean. However, its unique song made it easy for humans to track yet impossible for other whales to hear - and so, the Whale has wandered the open waters, year after year, alone.