Audio–Vision Substitution for Blind Individuals: Addressing Human Information Processing Capacity Limitations

In this contribution, we consider the factors that influence the information processing capacity of the person using sensory substitution devices, and the influence of how the translated information, here in audio, impacts performance. First, we review aspects of vision substitution by tactile and audio devices, and then we review key theory in human information processing limitations to devise and test use of an audio-vision substitution device, The vOICe, for recognizing visual objects with audio substitution for vision. Participants heard sonifications of two-dimensional (2-D) images and had to match them to alternatives presented either in visual or tactile modalities. To assess whether capacity limits constrain performance, objects were either presented with all information simultaneously (top and bottom as whole objects), or successively (top and bottom of the object one after the other). Performance was superior in the successive trials, indicative of a capacity limit in processing the auditory information. We discuss the implications for training protocols and design to provide a useful accessibility device for blind individuals.