Abstract
It is important in the safe driving support system to indicate a risk factor by clear sound image for reducing driver's reaction time. Since the frequency characteristics of acoustic transmission in a vehicle have many dips randomly, the square wave based alert sound with multiple frequency components was chosen. Considering the perspective of acoustic psychology, we focused attention on sound pressure balance with time difference (Haas effect) in the tuning process of sound image generation. The sensory evaluation tests showed that a driver can percept sound image clearly by the Haas effect and, therefore, driver's reaction time is possibly reduced.
