Localisation Properties of Wave Field Synthesis in a Listening Room

Abstract

Theoretic assumptions for sound field synthesis include an anechoic environment for reproduction. As in practice loudspeaker arrays are usually installed inside listening rooms, the synthesised sound field is altered by reflections. These physical changes potentially influence human perception of the sound field. This paper analyses the localisation properties of 2.5D Wave Field Synthesis in free field and in listening rooms with different reflection factors for varying spacings between the secondary sources, in comparison to the localisation of real sources in a listening experiment. Only the directional aspect of localisation in the horizontal plane, not distance or elevation, is investigated. Stimuli were presented using dynamic binaural synthesis. Binaural room impulse responses of the listening rooms were simulated with the image source method. The results show that accurate localisation in Wave Field Synthesis in a reflective environment is only possible for small secondary source spacings as has already been known for free field conditions from the literature. Furthermore, the localisation ability of listeners for both real and virtual sources is slightly degraded by reflections leading to a larger localisation error with a greater localisation blur.