PURPOSE: To eliminate the feeling of presence of sound image in the head and of fatigue in listening specific to the headphone listening, by processing sound reproducing original signals electrically in advance.

CONSTITUTION: A signal system comprising a sound signal input terminal 1, amplitude correction circuits 2,8 and a delay circuit 9 simulates the direct sound transmission system via adders 7,13,14 and inputs signals to left and right headphones 16,17 of a listner 15. A sound input signal is inputted to a multi-output delay signal generating circuit 4 via a variable resistor 3, each multi-delay output signal is arbitrarily selected at a changeover switch 5 and the signal is adjusted into two inverted signal levels via a variable resistor 6; one is inputted to the adder 7 and the other is to the adder 14. Further, the signal inputted to the adder 14 is inputted to a block system of an amplitude correction circuit 10 and a delay circuit 11 being a circuit forming the feeling of difference of both ears and inputted to the headphones 16,17 of the listner 15 with the signals from the adders 13, 14. Thus, the feeling of presence of sound image in the head and of fatigue in listening is eliminated.