Warusfel O., “Investigation of the perceived spatial resolution of higher ambisonics sound fields: a subjective evaluation involving virtual and real

Natural sound field can be reproduced through loudspeakers using ambisonics and Higher Order Ambisonics (HOA) microphone recordings. The HOA sound field encoding approach is based on spherical harmonics decomposition. The more components used to encode the sound field, the finer the spatial resolution is. As a result of previous studies, two HOA (2nd and 4th order) microphone prototypes have been developed. To evaluate the perceived spatial resolution and encoding artefacts on the horizontal plane, a localisation test was performed comparing these prototypes, a SoundField microphone and a simulated ideal 4th order encoding system. The HOA reproduction system was composed of twelve loudspeakers equally distributed on a circle. Thirteen target positions were chosen around the listener. An adjustment method using an auditory pointer was used to avoid bias effects of usual reporting methods. The human localisation error occurring for each of the tested systems has been compared. A statistical analysis showed significance differences when using the 4th order system, the 2nd order system and the SoundField microphone