Pedestrian awareness of the approach of quiet vehicles: Effect of approach informing sound and designing awareness
* Presenting author
Hybrid and electric vehicles are quieter than combustion-engine vehicles. To prevent accidents resulting from this quietness, an acoustic vehicle alerting system generates an approach informing sound (AIS). However, the recognition rate of the AIS is not high (~40%) and it might be difficult for pedestrians and others to notice the approach of quiet vehicles via hearing alone. To improve AIS recognition, we designed an AIS based on onomatopoeic sounds. A subjective evaluation experiment using these sounds revealed that people tended to evaluate noisy and rough sounds, such as those similar to the sound of a car traveling or an engine, as a good indication of a car traveling. Another experiment investigated the sounds that pedestrians actually use to recognize the approach of quiet vehicles. It was found most participants recognized the approach of a quiet vehicle not by the AIS but by the sounds emitted from the vehicle, such as road and wind noise. This tendency was also observed after participants correctly recognized the AIS. However, some participants reported that their awareness of AIS changed and they became more aware of AIS in daily life after the experiment. Designing awareness is effective and necessary for thedesign of AIS.