A Spatial Auditory Display for the Prevention of Pedestrian-motor Vehicle Collisions

Pedestrian-motor vehicle collisions account for over 6% of all workplace fatalities and are the leading cause of work related traumatic injury among highway workers. Interventions to reduce these accidents have focused primarily on vision. However, given the high demands on the visual attention of both pedestrian workers and vehicle operators, auditory warning might be a fruitful avenue for the reduction of traumatic injury to pedestrians who interact with motor vehicles. Recent research on the perception of auditory looming has shown that listeners tend to underestimate the amount of time it will take for an approaching sound source to reach them. The perceptual bias effectively signals that the source is closer than actual and thus, gives the listener more time than expected to avoid collision (the margin of safety effect). Here we identified some specific acoustic conditions that maximize the perceptual bias to hear looming sound sources as closer than actual. We made binaural recordings of approaching motor vehicles that produced either tones or broadband noise as they approached. Listeners underestimated vehicle arrival time in all conditions, but exhibited a significantly larger margin of safety for vehicles that produced tones as they approached. The results suggest that making approaching vehicles produce subtle tones by introducing a temporary a pavement treatment in work zones should increase the margin of worker safety.