In addition, the speaker 11RP is driven by the right ear signal SR for stereophonic reproduction (virtual surround). The speaker 11RS is driven by the reversed-phase signal SR′ obtained from the right ear signal SR by the signal processor 14R. In this case, the signal processor 14R adjusts the level of the reversed-phase signal SR′ in such a manner that the speakers 11RP and 11RS reproduce the right ear signal with bidirectional directivity.
In FIG. 3, dashed lines indicate the bidirectional directivity of the left ear signal reproduced by the speakers 11LP and 11LS. Note that, to simplify the drawing, the bidirectional directivity of the right ear signal reproduced by the speakers 11RP and 11RS are not illustrated.
The acoustic device 10B illustrated in FIG. 3 reproduces the left ear signal with bidirectional directivity by using the speakers 11LP and 11LS arranged back-to-back. Therefore, with regard to the left ear signal reproduced by the speakers 11LP and 11LS, the level of sound that propagates toward a right ear direction of the listener M (indicated by an arrow b) becomes lower than the level of sound that propagates toward a left ear direction of the listener M (indicated by an arrow a), and this makes it possible to reduce a crosstalk component related to the left ear signal.
