The room-in-room effect and its influence on perceived room size in spatial audio reproduction

In spatial audio it can be desirable to give the impression of a target space (e.g. a church). Often the reproduction environment is assumed acoustically dead; in practice most listening spaces (e.g. domestic living rooms) introduce significant reflections. The result is a room-in-room effect: a complex interaction of target and reproduction environments. This study investigates the influence on perceived room size. A number of target spaces were measured and rendered for loudspeaker playback. Reproduction rooms were measured, with variations produced via impulse response adjustment. Dynamic binaural playback allowed different target and reproduction room combinations, with participants judging the size of environment being reproduced. Results indicate the more reverberant of the target and reproduction rooms is most commonly heard