The object of this invention is to obtain the optimum music level by separately and independently performing the sound correction for the high-frequency range and low-frequency range according to the noise level. The invention comprises: a memory unit in which high-frequency-correction-level information, corresponding to the vehicle speed and music level, and low-frequency-correction-level information, corresponding to the low-frequency noise/music level ratio, are stored; a high-frequency-correction-level-information-acquisition unit that obtains high-frequency-correction-level information based on the vehicle speed and music level; and a low-frequency-correction-level-information-acquisition unit that obtains low-frequency-correction-level information based on the low-frequency noise/music level ratio; and it corrects the sound by a sound-quality-adjustment unit based on the high-frequency-correction-level information and low-frequency-correction-level information.