Dan Kish

Human echolocation is the ability of humans to detect objects in their environment by sensing echoes from those objects, by actively creating sounds – for example, by tapping their canes, lightly stomping their foot, snapping their fingers, or making clicking noises with their mouths – people trained to orient by echolocation can interpret the sound waves reflected by nearby objects, accurately identifying their location and size. This ability is used by some blind people for acoustic wayfinding, or navigating within their environment using auditory rather than visual cues. It is similar in principle to active sonar and to animal echolocation, which is employed by bats, dolphins and toothed whales to find prey.