To prevent an accident involving a pedestrian by making the person aware of the approach of a vehicle with low noises such as a hybrid car, electric car and fuel-cell car.

A sound generating device provided generates sound outward when an automobile starts running forward is running forward, or generates sound outward based on the speed of the automobile, or generates different kinds of sound according to the speed of the automobile, or generates sound having a high frequency component at the time of a high speed, or the device is equipped with a plurality of speakers. Furthermore, the device alters the direction of the generated sound according to the running, or is provided with a speaker whose direction is changed according to the running or is provided with a means for detecting irregularities with regard to the generation of sound so as to prevent intentional breaking.