Electric vehicle alert sounds are developed with the aim of the timely detection of the vehicles by pedestrians to guarantee the road safety. A commencing motion sound would activate when the vehicle is placed in drive or reverse and the driver's foot has come off of the brake. A proposal of the National Highway Traffic Safety Administration is that vehicle emits a continuous sound, when the vehicle is stationary. The aim of this study is the comparison of the commencing motion sound with the sound at idle regarding the detectability. The traffic condition, which was investigated in this study, is that a stopped vehicle near a pedestrian resumes motion. This situation occurs frequently at intersections. The stimuli variances were vehicle with sound at idle, vehicle without sound at idle, vehicle without sound at idle but with commencing motion sound. In this study, we examined the detection of vehicle sounds measuring the reaction time in presence of the ambient. Forty subjects participated in the experiment. Twenty-five subjects are sighted and fifteen subjects are visually impaired or blind. The results show that commencing motion sound can be more effective than sound at idle in the investigated situation.