Design of acoustic vehicle alerting system sound assuming listening situation of pedestrians

摘要

The role of acoustic vehicle alerting system (AVAS) sound is to tell pedestrians the approaching of quiet vehicles such as electric vehicles (EV) or hybrid-electric vehicles (HEV). We propose the AVAS sound that satisfies both of comfort and perception. The comfort of AVAS sound in this study means pedestrians do not feel noisy. The perception of AVAS sound means pedestrians to notice of the approaching quiet vehicles at safely avoidable distance. The AVAS sound model produced in this study has two peak frequencies. These models are two kinds of the steady sound with constant sound level and the fluctuating sound formed by modulating amplitude of steady sound. We measured impression of AVAS sound and perceptual distance. The impression of AVAS sound was measured by the psychological questionnaire using SD method. The perceptual distance: the distance between subject and HEV when the subject notices the approaching of HEV emitting the AVAS sound was measured in a test road. We also measured the perceptual distance of different listening situation such as standing or smartphone operation during walking. We show the sound characteristic to improve the comfort and the perception of AVAS sound, and the effect of the listening situation on the perceptual distance.