Due to the increasing use of electric vehicles in road traffic, there is a growing need to determine the perceptibility of vehicle sounds by pedestrians, since electric vehicles move almost silently at low speed. The aim of this project was to develop statements on the influence of an artificially generated stationary sound of electrically driven vehicles on safety. Furthermore, it was investigated whether a stationary sound can contribute to the avoidance of accidents. Various safety-related traffic situations, various stationary sounds and driving sounds were used for listening tests. For the stationary sounds, two driving sounds (UN-compliant driving sound and US-compliant driving sound) were used as a basis and additionally the frequency jump by percentage frequency change, a variation of the roughness by changing the frequency spacings of the tonal components and a total level jump when switching from stationary to driving sound varied so that a total of 58 different sound variations were examined in three traffic situations. A total of 40 subjects (including 20 blind and partially sighted) participated in the laboratory study. Both in the laboratory tests and in the subsequent field test with representatives of the European Blind Association, the automobile industry, the Federal Ministry of Transport and Digital Infrastructure, the Federal Highway Research Institute, it was shown that not every stationary sound in every driving situation leads to a better detection. Some sounds show significant effects in terms of detection capability for both the sighted and blind/partially sighted subjects. It has been shown that clear differences between driving and stationary sound, e.g. level jump or frequency jump positively influence the detectability. (Author/publisher)
Abstract