General Enhancement of Spatial Hearing in Congenitally Blind People

Abstract

Vision is thought to support the development of spatial abilities in the other senses. If this is true, how does spatial hearing develop in people lacking visual experience? We comprehensively addressed this question by investigating auditory-localization abilities in 17 congenitally blind and 17 sighted individuals using a psychophysical minimum-audible-angle task that lacked sensorimotor confounds. Participants were asked to compare the relative position of two sound sources located in central and peripheral, horizontal and vertical, or frontal and rear spaces. We observed unequivocal enhancement of spatial-hearing abilities in congenitally blind people, irrespective of the field of space that was assessed. Our results conclusively demonstrate that visual experience is not a prerequisite for developing optimal spatial-hearing abilities and that, in striking contrast, the lack of vision leads to a general enhancement of auditory-spatial skills.