A sound system for a vehicle including an engine and an audio device for an internal space of a cabin as sound sources disposed at given positions of the vehicle is provided. The audio device is switchable between a first mode in which an audio sound including both an audible sound and an inaudible sound for a human is reproduced in the cabin and a second mode in which an audio sound including the audible sound but not including the inaudible sound is reproduced in the cabin. The sound system includes a traveling state detector configured to detect a traveling state of the vehicle, and a switch controlling module executable by a processor configured to reproduce the audio sound in the first mode under a condition that a given traveling state is detected by the traveling state detector.