Navigation performance with a virtual auditory display: effects of beacon sound, capture radius, and practice.
OBJECTIVE: We examined whether spatialized nonspeech beacons could guide navigation and how sound timbre, waypoint capture radius, and practice affect performance. BACKGROUND: Auditory displays may assist mobility and wayfinding for those with temporary or permanent visual impairment, but they remain understudied. Previous systems have used speech-based interfaces. METHOD: Participants (108 undergraduates) navigated three maps, guided by one of three beacons (pink noise, sonar ping, or 1000-Hz pure tone) spatialized by a virtual reality engine. Dependent measures were efficiency of time and path length. RESULTS: Overall navigation was very successful, with significant effects of practice and capture radius, and interactions with beacon sound. Overshooting and subsequent hunting for waypoints was exacerbated for small radius conditions. A human-scale capture radius (1.5 m) and sonar-like beacon yielded the optimal combination for safety and efficiency. CONCLUSION: The selection of beacon sound and capture radius depend on the specific application, including whether speed of travel or adherence to path are of primary concern. Extended use affects sound preferences and quickly leads to improvements in both speed and accuracy. APPLICATION: These findings should lead to improved wayfinding systems for the visually impaired as well as for first responders (e.g., firefighters) and soldiers.