The Acuity of Echolocation: Spatial Resolution in Sighted Persons Compared to the Performance of an Expert Who Is Blind

Echolocation is a specialized application of spatial hearing that uses reflected auditory information to localize objects and represent the external environment. Although it has been documented extensively in nonhuman species, such as bats and dolphins, its use by some persons who are blind as a navigation and object-identification aid has received far less attention. Compared with the echolocation performance of an expert who is blind, sighted novices rapidly learned size and position discrimination with surprising precision. In this paper, the authors used a novel task to characterize the population distribution of echolocation skills in sighted persons and report the highest-known human echolocation acuity in the expert who is blind. They showed that perceptual learning of echolocation can be rapid without feedback and that some sighted individuals can be trained in echolocation to a level of precision that approaches that of expert echolocators who are congenitally blind. (Contains 5 figures and 2 tables.)