On the audio representation of radial direction

We present and evaluate an approach towards eyes-free auditory display of spatial information that considers radial direction as a fundamental type of value primitive. There are many benefits to being able to sonify radial directions, such as indicating the heading towards a point of interest in a direct and dynamic manner, rendering a path or shape outline by sonifying a continual sequence of tangent directions as the path is traced, and providing direct feedback of the direction of motion of the user in a physical space or a pointer in a virtual space. We propose a concrete mapping of vowel-like sounds to radial directions as one potential method to enable sonification of such information. We conducted a longitudinal study with five sighted and two blind participants to evaluate the learnability and effectiveness of this method. Results suggest that our directional sound mapping can be learned within a few hours and be used to aurally perceive spatial information such as shape outlines and path contours. Copyright 2011 ACM.