A soundings monitoring system for a vehicle includes a first camera capturing a fist imaging surface, a second camera capturing a second imaging surface, and a monitor for displaying a first image of the first imaging surface and a second image of the second imaging surface. A standard point is specified relative to the vehicle, the first image and the second image are synthesized and displayed on the monitor so that a coordinate position of the standard point in an expanded imaging surface from the first imaging surface and a coordinate position of the standard point in the second imaging surface match each other, and an imaginary line including the standard point and extending over the first image and the second image is displayed on the monitor in such a manner that the imaginary line is superimposed on the synthesized image of the first image and the second image.