A call environment generation method comprising, when speakers installed in an acoustic space are denoted by SP 1,..., SP N, positions to specify a call place in the acoustic space are denoted by P 1,..., P M, a filter coefficient to generate an input signal for a speaker SP n, hereinafter, referred to as first filter coefficient, is denoted by F n (ω) (n = 1,..., N, where ω is frequency), and a filter coefficient that is different from the first filter coefficient and is used to generate an input signal for the speaker SP n, hereinafter, referred to as second filter coefficient, is denoted by ~ F n (ω) (n = 1,..., N, where ω is frequency): a position acquisition step of acquiring, when a call environment generation apparatus detects a start signal of a call, a position P M_u (M u is integer satisfying 1 ≤ M u ≤ M) as a call place of the call; an acoustic signal generation step (S110-1) of generating, when the call environment generation apparatus detects the start signal, an acoustic signal that is obtained by adjusting volume of an acoustic signal to be reproduced during the call, hereinafter, referred to as call-time acoustic signal, by using a predetermined volume value; a first local signal generation step of causing the call environment generation apparatus to generate a sound signal S n as an input signal for the speaker SP n by filtering a voice signal of the call with the first filter coefficient F n (ω), where n = 1,..., N; and a second local signal generation step of causing the call environment generation apparatus to generate an acoustic signal A n as an input signal for the speaker SP n by filtering the call-time acoustic signal with the second filter coefficient ~ F n (ω), where n = 1,..., N,_ characterized in that transfer characteristics from the speaker SP n to a position P m are denoted by G n,m (ω) (n = 1,..., N, m = 1,..., M, where ω is frequency), the first filter coefficient F n (ω) (n = 1,..., N) is a filter coefficient determined as an approximation solution of the following expression: ∑ n = 1 N F n ω G n, M u ω = 1 ∑ n = 1 N F n ω G n, m ω = 0 m ≠ M u, and the second filter coefficient ~ F n (ω) (n = 1,..., N) is a filter coefficient determined as an approximation solution of the following expression: ∑ n = 1 N F ̃ n ω G n, M u ω = 0 ∑ n = 1 N F ̃ n ω G n, m ω = 1 m ≠ M u, and the first filter coefficient F n (ω) (n = 1,..., N) and the second filter coefficient ~ F n (ω) (n = 1,..., N) are recorded in a recording unit of the call environment generation apparatus. a position acquisition step of acquiring, when a call environment generation apparatus detects a start signal of a call, a position P M_u (M u is integer satisfying 1 ≤ M u ≤ M) as a call place of the call; an acoustic signal generation step (S110-1) of generating, when the call environment generation apparatus detects the start signal, an acoustic signal that is obtained by adjusting volume of an acoustic signal to be reproduced during the call, hereinafter, referred to as call-time acoustic signal, by using a predetermined volume value; a first local signal generation step of causing the call environment generation apparatus to generate a sound signal S n as an input signal for the speaker SP n by filtering a voice signal of the call with the first filter coefficient F n (ω), where n = 1,..., N; and a second local signal generation step of causing the call environment generation apparatus to generate an acoustic signal A n as an input signal for the speaker SP n by filtering the call-time acoustic signal with the second filter coefficient ~ F n (ω), where n = 1,..., N,_ characterized in that transfer characteristics from the speaker SP n to a position P m are denoted by G n,m (ω) (n = 1,..., N, m = 1,..., M, where ω is frequency), the first filter coefficient F n (ω) (n = 1,..., N) is a filter coefficient determined as an approximation solution of the following expression: ∑ n = 1 N F n ω G n, M u ω = 1 ∑ n = 1 N F n ω G n, m ω = 0 m ≠ M u, and the second filter coefficient ~ F n (ω) (n = 1,..., N) is a filter coefficient determined as an approximation solution of the following expression: ∑ n = 1 N F ̃ n ω G n, M u ω = 0 ∑ n = 1 N F ̃ n ω G n, m ω = 1 m ≠ M u, and the first filter coefficient F n (ω) (n = 1,..., N) and the second filter coefficient ~ F n (ω) (n = 1,..., N) are recorded in a recording unit of the call environment generation apparatus.