Difference in Sound Localizability between the Vision Impaired and Sighted Subjects Using the Three Pointing Interfaces

Abstract

In order to find out whether there is any difference in sound localizability between vision impaired and sighted individuals, we carried out the sound localization tasks of the subject's frontal azimuth by using three different sound source pointing methods in a semi-anechoic dark room. Twenty vision impaired and twenty normally sighted subjects participated in this experiment. The three pointing methods employed were (1) directing by the face, (2) directing by the body trunk on a revolving chair and (3) indicating a tactile direction cue horizontally placed in front of the subject position. Seven sound emitters were arranged at various angles (0°to ±80°) from the subject's midline and 2.0 m from the subject. The result showed that, in each angle, the difference between the vision impaired and sighted subjects were not very large at the center (0°). However, the localization performance of the vision impaired subjects was significantly better than that of the sighted subjects especially in the periphery (-80°and-X80°). In the whole frontal area (-80°to +80°from midline), the vision impaired subjects showed smaller deviations than the sighted subjects without regard to pointing methods. The present results indicated that the sound localizability of the vision impaired at the frontal azimuth is superior to the sighted particularly in the periphery.