Sound as sight: the discovery of bat echolocation

The question of how bats navigate in almost complete darkness has fascinated natural scientists since the 1700's. The famous anatomist Cuvier suggested that the wing membranes contained tactile sensors that allowed bats to navigate around objects. Others discovered that the ears seemed to be the most important organ (Spallanzani, Jurine and Hahn), but since bats rarely made sounds audible to humans, no one could discern how bats followed their ears. This conundrum was finally solved by the team of zoologist David Griffin and neuroscientist Robert Galambos in 1941, as America was entering World War II. By covering the eyes, ears, and mouths of bats, they determined that both the mouth and the ears were necessary for successful flight. They continued their studies with sound capture and brain monitoring technology, and determined that bats navigate by bouncing high-pitched calls off their surroundings and analyzing the echoes. This discovery tied in well with the sonar and radar biased thinking of the War, and eventually led to the ill-fated bat bomb project which was scrapped in favor of the atomic bomb.

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