Comparative Analysis of Image Sonification Algorithms for Assistive Technology of Sensory Substitution

Sensory substitution devices assist users with visual impairments to perceive their surroundings through sound generated by processing images from a head-mounted camera. To convey information in a user-friendly manner, images must be sonified according to a specific algorithm. The authors tested three different image sonification algorithms on two volunteers in object localization task. The participants’ performance was assessed by deviations along X-axis, Y-axis and absolute deviations. After the experiment the participants completed a survey about their strategies for object localization in each of three algorithms. The results of testing the algorithm 1 showed very similar outcomes among participants, with the worst performance in this algorithm. Algorithms 2 and 3 were the most productive for participants 001 and 002, respectively. According to the survey of the participants, the 2 algorithm was found to be the most intuitively understandable and convenient. The algorithm 2 modulates human binocular vision, which, presumably, made it more preferable for participants.