Quiet cars and blind pedestrians

People who are blind use traffic sounds to determine alignment, verify relative position to a street, identify their location, and decide an appropriate time to cross a street. With quieter vehicles, these pedestrians often do not have the amount or kind of acoustic information needed to make good, reliable travel decisions. Blind participants listened to internal combustion vehicles and hybrid vehicles (with and without added artificial sounds) approaching while moving forward, approaching while backing, and turning at an intersection. Participants indicated when they heard a vehicle and the direction of travel. Participants also aligned themselves to passing vehicles or indicated when crossable gaps between vehicles existed. Performance degraded most when ambient sound levels increased. However, even under extremely low ambient conditions, some tasks were not performed well. Some artificial sounds improved performance of particular tasks, but no artificial sound adequately enhanced performance in all ta...