A sound signal processing method comprising: receiving a line-inputted sound signal from a sound source; controlling a volume of the line-inputted sound signal; and generating an early reflected sound control signal to reproduce an early reflected sound of a predetermined space that is a target for reproducing a sound field using the line-inputted sound signal having the controlled volume; the method characterized by obtaining a plurality of sound signals from a plurality of microphones (12A, 12B, 12C); generating a reverberant sound control signal to reproduce a reverberant sound of the predetermined space using the sound signals from the plurality of microphones (12A, 12B, 12C) and the line-inputted sound signal having the controlled volume; and outputting, via a speaker (51A, 51B, 51C, 51D, 61A, 61B, 61C, 61D, 61E, 61F), the early reflected sound and the reverberant sound, wherein: the speaker (51A, 51B, 51C, 51D, 61A, 61B, 61C, 61D, 61E, 61F) includes a first speaker group (61A, 61B, 61C, 61D, 61E, 61F) and a second speaker group (51A, 51B, 51C, 51D); a plurality of sound signals for the first speaker group (61A, 61B, 61C, 61D, 61E, 61F) are generated based on the line-inputted sound signal and the plurality of sound signals of the plurality of microphones(12A, 12B, 12C); and a plurality of sound signals for the second speaker group (51A, 51B, 51C, 51D) are generated based on the sound signals of only the line-inputted sound signal. receiving a line-inputted sound signal from a sound source; controlling a volume of the line-inputted sound signal; and generating an early reflected sound control signal to reproduce an early reflected sound of a predetermined space that is a target for reproducing a sound field using the line-inputted sound signal having the controlled volume; the method characterized by obtaining a plurality of sound signals from a plurality of microphones (12A, 12B, 12C); generating a reverberant sound control signal to reproduce a reverberant sound of the predetermined space using the sound signals from the plurality of microphones (12A, 12B, 12C) and the line-inputted sound signal having the controlled volume; and outputting, via a speaker (51A, 51B, 51C, 51D, 61A, 61B, 61C, 61D, 61E, 61F), the early reflected sound and the reverberant sound, wherein: the speaker (51A, 51B, 51C, 51D, 61A, 61B, 61C, 61D, 61E, 61F) includes a first speaker group (61A, 61B, 61C, 61D, 61E, 61F) and a second speaker group (51A, 51B, 51C, 51D); a plurality of sound signals for the first speaker group (61A, 61B, 61C, 61D, 61E, 61F) are generated based on the line-inputted sound signal and the plurality of sound signals of the plurality of microphones(12A, 12B, 12C); and a plurality of sound signals for the second speaker group (51A, 51B, 51C, 51D) are generated based on the sound signals of only the line-inputted sound signal. the speaker (51A, 51B, 51C, 51D, 61A, 61B, 61C, 61D, 61E, 61F) includes a first speaker group (61A, 61B, 61C, 61D, 61E, 61F) and a second speaker group (51A, 51B, 51C, 51D); a plurality of sound signals for the first speaker group (61A, 61B, 61C, 61D, 61E, 61F) are generated based on the line-inputted sound signal and the plurality of sound signals of the plurality of microphones(12A, 12B, 12C); and a plurality of sound signals for the second speaker group (51A, 51B, 51C, 51D) are generated based on the sound signals of only the line-inputted sound signal.