Volume control apparatus, volume control method and volume control program

Abstract

A volume control device controls reproduced sound levels at the listening position set to the seat in the vehicle compartment, and gives the phase difference to an externally inputted sound signal, and supplies the sound signals to two speakers. Here, the phase difference is calculated, at a frequency lower than a predetermined frequency, for sound signals reproduced by the speakers in front of and behind the listening position. Also, the phase difference is calculated to make a reproduced sound level at the listening position smaller than the reproduced sound level when the sound signal is reproduced by either one of the pair of speakers. Preferably, the listening position includes two evaluation points, and the reproduced sound level at the listening position is a sum of the reproduced sound levels at the two evaluation points. Thus, the reproduced sound may become small at an arbitrary listening position in the acoustic space.