Provided is a signal processing apparatus that can replicate, in a real space, an environment different from the real space by granting an acoustic characteristic different from that of the real space, to a sound released in the real space. There is provided a signal processing apparatus including a control unit configured to decide a predetermined acoustic characteristic for causing a user to hear a collected ambient sound of the user in a space having a different acoustic characteristic, in accordance with content being reproduced, or an action of a user, and to add the decided acoustic characteristic to the ambient sound.