A signal processing device comprising: an input unit configured to input a sound collection signal of a sound produced by a user which is obtained through sound collection by a plurality of microphones which are disposed to surround the user with inward directivity in a reproduction environment (Site B); an acoustic signal processing unit configured to obtain a reproduction signal for reproducing a sound field in a measurement environment (Site A) by performing a process on the sound collection signal input by the input unit based on a transfer function, the transfer function is measured based on a result obtained by sequentially emitting predetermined sounds from speakers at each of a plurality of positions which are set on a first closed surface with outward directivity in the measurement environment and then collecting the sequentially emitted sounds with microphones at a plurality of positions which are set on a second closed surface with outward directivity in the measurement environment and the transfer function indicates how the sounds emitted from the respective plurality of positions on the first closed surface are transferred to the respective plurality of positions on the second closed surface; and a sound emission control unit configured to cause a plurality of speakers which are disposed to surround the user and perform sound emission with inward directivity in the reproduction environment to emit a sound based on the reproduction signal obtained by the acoustic signal processing unit, characterized in that, when a closed surface having the same size and shape as the first closed surface is set as a third closed surface, a closed surface having the same size and shape as the second closed surface is set as a fourth closed surface, a closed surface having the same size and shape as a closed surface formed by the plurality of microphones that are disposed in the reproduction environment to surround the user is set as a fifth closed surface, and a closed surface having the same size and shape as a closed surface formed by the plurality of speakers that are disposed in the reproduction environment to surround the user is set as a sixth closed surface, the acoustic signal processing unit performs a process on the sound collection signal based on a transfer function obtained by converting a transfer function that is measured in the measurement environment based on a transfer function from each position on the fifth closed surface to each position on the third closed surface and a transfer function from each position on the sixth closed surface to each position on the fourth closed surface when the third to sixth closed surfaces are set under the same environment. an input unit configured to input a sound collection signal of a sound produced by a user which is obtained through sound collection by a plurality of microphones which are disposed to surround the user with inward directivity in a reproduction environment (Site B); an acoustic signal processing unit configured to obtain a reproduction signal for reproducing a sound field in a measurement environment (Site A) by performing a process on the sound collection signal input by the input unit based on a transfer function, the transfer function is measured based on a result obtained by sequentially emitting predetermined sounds from speakers at each of a plurality of positions which are set on a first closed surface with outward directivity in the measurement environment and then collecting the sequentially emitted sounds with microphones at a plurality of positions which are set on a second closed surface with outward directivity in the measurement environment and the transfer function indicates how the sounds emitted from the respective plurality of positions on the first closed surface are transferred to the respective plurality of positions on the second closed surface; and a sound emission control unit configured to cause a plurality of speakers which are disposed to surround the user and perform sound emission with inward directivity in the reproduction environment to emit a sound based on the reproduction signal obtained by the acoustic signal processing unit, characterized in that, when a closed surface having the same size and shape as the first closed surface is set as a third closed surface, a closed surface having the same size and shape as the second closed surface is set as a fourth closed surface, a closed surface having the same size and shape as a closed surface formed by the plurality of microphones that are disposed in the reproduction environment to surround the user is set as a fifth closed surface, and a closed surface having the same size and shape as a closed surface formed by the plurality of speakers that are disposed in the reproduction environment to surround the user is set as a sixth closed surface, the acoustic signal processing unit performs a process on the sound collection signal based on a transfer function obtained by converting a transfer function that is measured in the measurement environment based on a transfer function from each position on the fifth closed surface to each position on the third closed surface and a transfer function from each position on the sixth closed surface to each position on the fourth closed surface when the third to sixth closed surfaces are set under the same environment.