When underwater, humans cannot determine where a sound comes from. Sound travels about five times faster there than on land. That makes directional hearing, or sound localization, nearly impossible because the human brain determines the origin of a sound by analyzing the time difference between its arrival at one ear versus the other. By contrast, behavioral studies have shown that fish can locate sound sources such as prey or predators. But how do they do it? Neuroscientists from Charité – Universitätsmedizin Berlin have solved the puzzle, describing the auditory mechanism of a tiny fish in the journal Nature.*