Investigation into the impact of 3D surround systems on spatial audio quality focussing on envelopment

Abstract

Current 2D surround systems have benefitted from significant research that has helped identify attributes related to listener preference. Now with high definition visuals, including 3D cinema, there is a need to further develop spatial audio systems. One method would be to add height channels, however it is unknown how this will impact on the listening experience and the spatial audio quality. This paper investigates the spatial capabilities of a number of different loudspeaker configurations including stereo, 2D surround systems, and 3D systems focussing on the subjective attribute of envelopment. An initial computer simulation of a number of 2D and 3D surround systems utilising decorrelated white noise signal and using a measurement closely related to the human perception of spaciousness, IACC (inter-aural cross correlation) was used identifying variations in IACC between systems. The 8 systems tested in the simulation were then used in a subjective experiment again driving each speaker in the 2 and 3D arrays with independent de-correlated noise, where it was found that there were no significant differences between the 2D and 3D surround systems under test in terms of envelopment. A strong negative correlation was found between the objective measure and the subjective scores.