Vertical sound localization in blind humans

It is widely held that early-blind people compensate their visual loss by a general sharpening of spatial hearing. The present study reports a possible exception to this view: when the vertical position (elevation) of a sound source had to be localized, four out of six early-blind subjects exhibited systematic deviations in pointing, while two early-blind subjects were as accurate as sighted controls. On the other hand, blind and sighted individuals were able to judge relative positions of different sound locations with similar precision. These results suggest that visual experience may be used to accurately calibrate the relation between the vertical coordinates of auditory space and body, but is not needed to develop sufficiently high resolution of spatial hearing.