Echolocation

From Teng, Puri & Whitney (2011). Echolocating organisms represent their external environment using reflected auditory information from emitted vocalizations. This ability, long known in various non-human species, has also been documented in some blind humans as an aid to navigation, as well as object detection and coarse localization. Surprisingly, our understanding of the basic acuity attainable by practitioners—the most funda- mental underpinning of echoic spatial perception—remains crude. We found that experts were able to discriminate hor- izontal offsets of stimuli as small as *1.2° auditory angle in the frontomedial plane, a resolution approaching the maxi- mum measured precision of human spatial hearing and comparable to that found in bats performing similar tasks. Furthermore, we found a strong correlation between echo- location acuity and age of blindness onset. This first measure of functional spatial resolution in a population of expert echolocators demonstrates precision comparable to that found in the visual periphery of sighted individuals.

From Teng & Whitney (2011) . Compared with the echolocation performance of an expert who is blind, sighted novices rapidly learned size and position discrimination with surprising precision. We used a novel tak 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.