Pursuit of Realistic Vehicle Acceleration Sounds Based on Discomfort Index

<div class="section abstract"><div class="htmlview paragraph">Contemporary Japanese society relies heavily on vehicles for transportation and leisure. This has led to environmental concerns owing to vehicle emissions, prompting a shift toward environmentally friendly alternatives, such as clean diesel and electric vehicles. Clean diesel vehicles aim to reduce harmful emissions, whereas electric vehicles are favored because of their minimal emissions and quiet operation. However, the lack of engine noise in electric vehicles can make it difficult for drivers to perceive speed changes, potentially increasing the risk of accidents, and simply amplifying all sounds is not viable because it may cause discomfort. Therefore, this study explored how deviations from expected engine sounds affect the perceived sound quality and vehicle performance assessment. Unlike traditional gasoline-powered and clean diesel vehicles, electric vehicles produce very little running noise, which makes road surface noise more prominent. Given the novelty of electric vehicles and the challenges associated with their driving noises, this study focused on acceleration sounds, analyzing whether incorporating typical engine noises, such as rumbling and humming, could enhance realism. The comfort levels of the participants with various acceleration sounds were examined based on their driving experience, highlighting the complex relationship between sound expectations and vehicle operation.</div></div>