Sound reproduction is controlled so as to be heard in the optimal state for the hearing function specific to elderly people. A frequency characteristic setting portion for setting the frequency characteristics of an inputted sound signal, and a sound volume setting portion for variable controlling the volume is disclosed. The frequency characteristic setting portion changes a frequency characteristic in which a sound band including a human voice band is emphasized to a frequency characteristic in which the characteristics of a gain in accordance with a frequency gradually becomes flat with an increase in the volume set by the sound volume setting portion. As a result, the frequency band of the human voice is strongly emphasized so as to help elderly people hear it at a low volume, and, as the volume grows higher, a frequency characteristic is changed to a flatter frequency characteristic, thereby making it possible to output easy-to-hear sound while reducing inconvenience caused by the emphasis of a specific frequency band.