To excellently adjust reproduced sound quality with a simple configuration in performing audio reproduction.

Frequency characteristics of audio data acquired by input or reproduction are analyzed, equalizing processing for increasing gains is performed for the frequency bands much included in the audio data, and the audio data subjected to the equalizer processing are subjected to output processing. Also, the equalizing processing status based on a result of analyzing the frequency characteristics is stored, and when audio data are newly analyzed, a new equalizer processing status is set by summing average between the result of new analysis and the equalizer processing status previously stored, and storage data are updated in the new equalizer processing status.