In correspondence with the left and right external ears of a listener occupying a seat, a three dimensional sound field reproducing unit includes at least more than two speakers disposed on a headrest on the top of a backrest of the seat, and three dimensional signal processing means which converts an output signal from a sound source into a three dimensional sound field signal for supplying it to each of the speakers. Three dimensional sound field with high accuracy and fidelity is reproduced near the external ears of the listener.