Three-Dimensional Room Transfer Function Parameterization Based on Multiple Concentric Planar Circular Arrays

This study proposes a three-dimensional room transfer function (RTF) parameterization method based on multiple concentric planar circular arrays, which exhibits robustness to variations in the positions of both the receiver and source. According to the harmonic solution to the wave equation, the RTFs between two spherical regions (sound source and receiver) in a room can be expressed as a weighted sum of spherical harmonics, whose weight coefficients serve as the RTF parameters, which can be estimated by placing multiple concentric planar circular arrays composed of monopole-source pairs (MSPs) and multiple concentric planar circular arrays composed of omnidirectional-microphone pairs (OMPs) in respective source and receiver regions. We use MSP arrays to generate required outgoing soundfields originating from a source region. We derive a method to use OMP arrays to estimate RTF parameters that are concealed within the captured soundfield, which can be employed to reconstruct the RTF from any point in the source region to any point in the receiver region. The accuracy of the RTF parameterization method is validated through simulation testing.