Objective evaluation of a three-dimensional sound field reproduction system

We present the results of an empirical evaluation of a three-dimensional sound field reproduction system consisting of 32 loudspeakers installed in a hemi-anechoic room at the University of Sydney. This loudspeaker arrangement allows up to third-order, two-dimensional, and fourth-order, three-dimensional Higher Order Ambisonic (HOA) reproduction of sound fields. The ability of this system to recreate a known sound field at the ears of a listener is evaluated using measurements with an acoustic manikin in the optimal listening position. In particular, we compare the Interaural Time Delay (ITD) and the Interaural Level Difference (ILD) generated by HOA for different sound source angles against reference values measured in an anechoic room. In addition, the influence of a listener’s position on the quality of the reproduction is investigated based on measurements performed for different positions of the manikin around the "sweet spot".