human echolocation is the ability of humans to detect objects in their environment by sensing echoes from those objects. by actively creating sounds â for example, by tapping their canes, lightly stomping their foot, snapping their fingers, or making clicking noises with their mouths â 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. ==background== human echolocation has been known and formally studied since at least the 1950s.richard l. welsh, bruce b. blasch, online foundations of orientation and mobility, american foundation for the blind, 1997; which cites s. o. myers and c. g. e. g. jones, "obstable experiments: second report", teacher for the blind 46, 47â62, 1958. in earlier times, human echolocation was sometimes described as "facial vision".raymond j corsini, the dictionary of psychology, psychology press (uk), 1999, isbn 1-58391-028-x.m. supa, m. cotzin, and k. m. dallenbach. "facial vision" - the perception of obstacles by the blind. the american journal of psychology, april 1944.cotzin and dallenbach. "facial vision": the role of pitch and loudness in the location of obstacles by the blind. the american journal of psychology, october 1950. the field of human and animal echolocation was surveyed in book form as early as 1959.griffin, donald r., echos of bats and men, anchor press, 1959 (science and study series, seeing with sound waves) see also white, et al., (1970)white, j. c., saunders, f. a., scadden, l., bach-y-rita, p., & collins, c. c. (1970). seeing with the skin. perception & psychophysics, 7, 23-27. ==mechanics== vision and hearing are closely related in that they can process reflected waves of energy. vision processes light waves as they travel from their source, bounce off surfaces throughout the environment and enter the eyes. similarly, the auditory system processes sound waves as they travel from their source, bounce off surfaces and enter the ears. both systems can extract a great deal of information about the environment by interpreting the complex patterns of reflected energy that they receive. in the case of sound, these waves of reflected energy are called "echoes". echoes and other sounds can convey spatial information that is
Blindness Sonar