On Visual, Vibrotactile, and 3D Audio Directional Cues for Dismounted Soldier Waypoint Navigation

We compared a visual GPS, a tactile torso belt, and a 3D audio display in a waypoint navigation task for dismounted soldiers. Using these displays one at a time, the soldier's main tasks were to walk as fast and straight as possible towards the waypoints while visually scanning the terrain for detection of target flags. The results showed that all three types of displays gave similar navigation precision and target detection performance. The visual display entailed a somewhat higher navigation speed than the tactile and 3D audio displays. Both the visual and 3D audio displays, however, were rated as directing attention away from the terrain more than the tactile display. Compared to the tactile display, a higher mental workload was reported for the 3D audio, which was also rated least suitable for operational use in navigation tasks. Yet, the soldiers' ability to localize directions to waypoints with the 3D audio display may point to its potential use for radio communication and cueing of directions to threats. In an overall evaluation, eight soldiers preferred the tactile display and four the visual, while none preferred the 3D audio. We discuss the results mainly regarding shortcomings of the study and the possibility of developing and combining the three display types for the dismounted soldier.