Diagram Presentation using Loudspeaker Matrix for Visually Impaired People: Sound Characteristics for their Pattern Recognition

People with total visual impairments experience difficulty in understanding graphical information. They can comprehend graphics through tactile devices including pin matrices with audio characteristics presented using voice. Although these systems can represent static figures, it is difficult to use them for presenting moving images or details of high-resolution images. For solving this issue, we focused on the characteristics of auditory perception, including time resolution and frequency detection. In this paper, we propose a loudspeaker matrix system that displays 2D patterns such as trajectories or figures. We mainly investigated the design implications of acoustic presentation methods, including readily perceivable sound paths. The results indicate that effective presentation with a loudspeaker matrix would be realized by imposing the following conditions: sound type and duration should be determined as white noise and adjusted for the individual user, respectively.