Proceedings of the 10th Convention of the
European Acoustics Association
Forum Acusticum 2023


Politecnico di Torino
Torino, Italy
September 11 - 15, 2023





Session: A11-02: Virtual Reality and Hearing Research - Part II
Date: Tuesday 12 September 2023
Time: 16:40 - 17:00
Title: Moving the Ambisonics Sweet-Spot by Adapting Loudspeaker Equalization and Ambisonics Decoding
Author(s): M. Kuntz, Audio Information Processing, Technical University of Munich, Arcisstraße 21, 80333 Munich, Germany
B.U. Seeber, Audio Information Processing, Technical University of Munich, Arcisstraße 21, 80333 Munich, Germany
Pages: 1805-1808
DOI: https://www.doi.org/10.61782/fa.2023.1078
PDF: https://dael.euracoustics.org/confs/fa2023/data/articles/001078.pdf
Conference proceedings
Abstract

Virtual acoustic environments are becoming a widespread tool in hearing research. Free-field reproduction allows the design of more realistic experiments, where participants can turn their head and move around without the need for individualized HRTFs or head tracking. A limitation of commonly used sound field synthesis techniques, in particular Ambisonics, is their decreasing accuracy with increasing distance from the center of the loudspeaker array. While participants can move around in the reproduced sound field, it is not possible to control the sound field they receive at off-center positions to the degree required for hearing research. In this work, we consider a two-dimensional 36-loudspeaker array, where the loudspeakers are typically equalized in the center of the array. We investigate the possibility of moving the Ambisonics sweet-spot by equalizing the loudspeakers at different points inside the loudspeaker array. Simulations show that at least 50% of the sweet-spot size is preserved when moving the equalization point. An adaptation of the relative loudspeaker positions for the Ambisonics decoding reduces the parallax shift observed in Ambisonics systems.