Effects of vehicle horn acoustic properties on auditory impressions and the interpretation of reasons for horn use by other drivers1)

In Japan, vehicle horns have been used as a means of communication between drivers, including the expression of gratitude. On the other hand, psychologically negative reactions are occasionally aroused by vehicle horn use, not only in drivers but also in pedestrians. Based on the assumption that horns are heard both inside and outside vehicles, in the current study we conducted psychoacoustic experiments to examine the effects of the acoustic properties of vehicle horns on auditory impressions and interpretations of the reasons for horn use by other drivers to better understand how negative reactions to horns can be reduced. Our results showed that horns heard from outside of vehicles were evaluated as more unpleasant and annoying than those heard from inside because the former stimuli were louder than the latter. Furthermore, impressions of unpleasantness and annoyance were stronger as the duration of horn use became longer. From these results, we concluded that the negative impressions induced by vehicle horns could be reduced by modifying the acoustic properties of horns, such as their temporal features. Furthermore, regarding the judgment of other drivers' reasons for horn use, it was found that a listener's interpretations of other drivers' reasons for using a horn could also be changed by modifying the temporal features of horns to improve their negative impressions.