On the Risk of Quiet Vehicles to Pedestrians and Drivers

Abstract

Technology has enabled the mass production of hybrid and electric vehicles. Interest in these alternative-energy vehicles has been heightened due to air quality concerns in urban areas. However, these vehicles are capable of very quiet operation, which could have negative side effects on pedestrian and driver safety because of the lack of sound cues. A survey of 380 people was conducted to explore interest and concerns about electrically powered vehicles. The data show that there is substantial positive interest in driving quiet hybrid and electric cars. However, in the role of pedestrian, participants expressed concern over the reduced auditory cues to the presence of a moving vehicle. Implications of quiet vehicles are discussed including the additional consideration of reduced driver awareness of their speed. Precautionary measures and suggestions for effective engine noise substitutes are presented.

How Should an Electric Vehicle Sound? User and Expert Perception

“…This result is in accordance with previous studies on the subject [25][26]. Already in third place, we find that users prefer 'no sound' (see Figure 3).…”

“…The most occurring answer of users to the question of what an EV should sound like was: "like a regular car" (see Figure 3). This result, in accordance with literature [25][26], is a sign of the importance of the psychological inertia and of the complexity of the design problem. On this topic, the opinions of sound experts varied: they made 'design-oriented' propositions, describing how they would design a sound for an EV.…”

“…With respect to users' preferences towards external vehicle sounds, in their study with a panel of 380 people, Wogalter et al [25] identify the 'traditional engine' as the predominant response to what type of sound is most appropriate. Similarly, Nyeste et al [26] conducted a preference study on a set of potential sounds for EVs with the semantic differential method and showed that the 'traditional sound' of a combustion engine is the most acceptable.…”

On Adding Sound to Quiet Vehicles

“…The present research follows from previous work by Wogalter et al (2001). Their first study examined attitudes about electric and hybrid vehicles including safety issues associated with their quietness.…”

Knowledge in Sound Design: The Silent Electric Vehicle—A Relevant Case Study

“…Nevertheless, we compiled a list of existing works, and in particular, two experimental studies from Wogalter et al [17] and Nyeste and Wogalter [18] (see [11], for a more detailed review). In their joint studies, they tried to define sound categories that might provide acceptable auditory cues for quiet vehicles, respectively, in terms of object association and acceptability.…”