Developing Dynamic Audio Navigation UIs to Pinpoint Elements in Tactile Graphics

Access to complex graphical information is essential when connecting blind and visually impaired (BVI) people with the world. Tactile graphics readers enable access to graphical data through audio-tactile user interfaces (UIs), but these have yet to mature. A challenging task for blind people is locating specific elements–areas in detailed tactile graphics. To this end, we developed three audio navigation UIs that dynamically guide the user’s hand to a specific position using audio feedback. One is based on submarine sonar sounds, another relies on the target’s coordinate plan x and y-axis, and the last uses direct voice instructions. The UIs were implemented in the Tactonom Reader device, a new tactile graphic reader that enhances swell paper graphics with pinpointed audio explanations. To evaluate the effectiveness of the three different dynamic navigation UIs, we conducted a within-subject usability test that involved 13 BVI participants. Beyond comparing the effectiveness of the different UIs, we observed and recorded the interaction of the visually impaired participants with the different navigation UI to further investigate their behavioral patterns during the interaction. We observed that user interfaces that required the user to move their hand in a straight direction were more likely to provoke frustration and were often perceived as challenging for blind and visually impaired people. The analysis revealed that the voice-based navigation UI guides the participant the fastest to the target and does not require prior training. This suggests that a voice-based navigation strategy is a promising approach for designing an accessible user interface for the blind.