Influence of Sound and Vibration on Perceived Overall Ride Comfort - A Comparison between an Electric Vehicle and a Combustion Engine Vehicle

Journal article, 2023

There are significant differences in sound and vibration between combustion engine vehicles (CV) and electric vehicles (EV), which may affect occupants' experiences of overall ride comfort. There have been few studies on human perception of the overall ride comfort in EVs. The purpose of this study is to identify how sound and vibration influence perceived overall ride comfort in an EV under different driving scenarios and to study differences between an EV and a CV in terms of the influences of sound and vibration on the perceived ride comfort. The user study compared the experiences of ten participants' riding in a CV and an EV through eight typical driving scenarios. The subjective judgment and objective measurements showed that in the EV, dynamic discomfort was dominated by high-frequency tones from electric components. The influence of sound on dynamic discomfort was more pronounced in the EV, and the causes of sound annoyance differed between the EV and the CV. In the CV, sound annoyance was primarily attributed to tire noise at lower speeds and wind noise at higher speeds. Meanwhile in the EV, sound annoyance was caused by high-frequency tonal sounds from the electric motor, especially in scenarios at lower speeds. When switching the CV engine on and off, low-frequency sounds and vibrations were pronounced. The EV produced no significant vibration during start/stop and emitted only a designed signature sound. The conclusion is that under different driving scenarios, sound and vibration have different influence on the perceived overall ride comfort in the CV and EV. Thus, ride discomfort in the CV and EV are affected by various properties of sound and vibration.