Sound localization with monocular vision

An experiment was carried out to determine whether sudden loss of vision in one eye would result in a bias in sound localization in the direction of the viewing eye. Fifteen normal-sighted young adults were tested binocularly and with the right or left eye covered. Within each vision condition, sound localization was assessed using three different arrays of six loudspeakers, positioned frontally and on the right and left sides of space, in combination with two stimuli, a one-third octave noise band centred at 4 kHz and broadband noise. These assessed the utilization of mainly the interaural level difference cue and binaural and spectral cues in combination, respectively. One block of 90 speaker identification trials was presented for each of the 18 conditions. For the lateral arrays in combination with the broadband noise stimulus, monocular vision resulted in decreased accuracy on the contralateral side. Errors were in the direction of the viewing eye. While monocularity resulted in performance decrements with the 4-kHz stimulus, the error pattern was not consistent. These results support the hypothesis of visually guided auditory adaptation of binaural and spectral cues in combination in response to sudden deprivation of vision in one eye.