Evaluation of the effectiveness for drivers of an in-vehicle sound environment where nature sounds are being played

Abstract

In this study, assuming an in-vehicle environment during automatic driving, we investigated the effectiveness of a sound environment where nature sounds are being played, which are considered to have no significant differences in passenger preferences, with the aim of improving comfort, including not only maintaining arousal but also aspects such as mental/physical activation. In the first experiment, two types of driving movies were prepared in consideration of the influence of visual information, and a subjective evaluation experiment of nature sounds was conducted to determine what kind of nature sound can improve comfort regardless of the driving environment. As a result, it was found that the sound source that can contribute to improving comfort and arousal in the in-vehicle environment is birdsong, and that a sound source with a particularly high frequency component is more appropriate. In the second experiment, the contribution of playing the nature sound, which was considered optimal in the first experiment, to maintaining driver arousal was determined. The results suggest that the five-second nature sound can speed up reaction time and reduce reaction delays, and that the effect may be particularly significant at 10-second interval presentations or at 30-second interval presentations with relatively high levels.