PURPOSE: To improve the function of a television receiver, etc., by discriminating the frequency component of an input audio signal, and automatically setting appropriate sound quality corresponding to the frequency component.

CONSTITUTION: This device is provided with a sound input terminal 1, a low- pass filter 2, a band-pass filter 3, a high-pass filter 4, first to third integration circuits 5-7, first to third A/D conversion circuits 8-10, a comparator part 11, a memory part 12, a microcomputer 13 for control, a sound quality control part 14, right and left audio signal input terminals 15, 16, and audio signal output terminals 17, 18. The frequency component of a reception audio signal is compared with reference signals stored in advance by divided into a low-pass area, a middle-pass area, and a high-pass area at every low-pass area, middle- pass area, and high-pass area by using the filters 2-4, and the sound quality can be automatically set at constant sound quality set in advance based on comparison data. Thereby, it is possible to dispense with the operation of a sound quality adjusting volume and the selection operation of a button in the television receiver.