PURPOSE: To increase the stereo effect, by installing two speakers which radiate sound waves to left and right ears of clews adjacently after each seat of an automobile.

CONSTITUTION: A speaker unit 7 radiating sound waves to a clew ML seated at the left side of a rear seat 2 of a car, is located just behind the seat. Speakers 8, 9 are located in the speaker unit 7 to locate them so that sound waves can be radiated to left and right ears (P, Q) of the clew ML. A speaker unit 7' consisting of speakers 8', 9' is located similarly to a clew MR at the right side. Left and right channel signals SL, SR outputted from the audio signal output section drive the speakers 8, 8', 9, 9', and the clews ML, MR can listen to the signals with left ears for left channel signal SL and with right ears for right channel signal SR with good balance. Thus, the stereo effect can be increased.