A war situation detection unit (205) detects a situation of a battle controlled by a battle control unit (204) and superiority of enemy or friend. An audio data acquisition unit (209) acquires audio data specified according to the situation of the battle. Moreover, the audio data acquisition unit (209) detects superiority of enemy or friend at each predetermined timing and acquires corresponding arbitrary audio data according to the superiority state detected. The audio data acquisition unit (209) sends the acquired audio data together with the priority to a queue buffer (210). An audio output unit (212) reads out the audio data according to the priority from the queue buffer (210), synthesizes an audio signal from the audio data which has been read out, and outputs the audio from a predetermined loudspeaker.