Mental map generation assistance tool using relative pitch difference and angular information for visually impaired people

This study proposes a sine wave-based auditory user interface for assisting visually impaired persons with creating mental maps of walking environments. Wall shapes are considered as fundamental map features of the map in building a mental map of a space. Therefore, the distance and direction to walls are important. In this study, we present information to users via sound. To show the distance to and direction toward walls, a point on the walls should be selected continuously. Then, the distance and the direction to the point can be presented sequentially using sound. Based on this distance and direction information, users can reconstruct wall shapes in their mind. However, we found that the accuracy of such reconstruction depended on wall orientation. To realize the correct reconstruction of wall shapes as mental maps, we decided to provide angle information between two walls to a user in addition to distance and direction information. In this paper, sound designs for presenting distance, direction, and angle information of walls are described. Additionally, results of the experiments for evaluating the proposed method are presented. The experimental results show that angle information was useful for building a mental map using the proposed auditory presentation scheme.