Sound field reconstruction in reverberant environments with rigid spherical microphone arrays

To achieve accurate sound field reconstruction in reverberant environments, a method based on the principle of equivalent sources and a mixed-wave model is proposed with rigid spherical microphone arrays. The method assumes that the near-field sound sources are sparsely distributed and decomposes the sound field into the direct sound components modelled by monopole sources and the reflected sound components represented by plane waves, thereby constructing a mixed-wave model. The alternating direction method of multipliers is then used to alternately estimate the weights of monopole sources and plane waves, enabling the sound field decoupling. Finally, the target sound field in the region of interest is reconstructed using the obtained weights. Both numerical simulations and finite element method-based virtual validation experiment demonstrate that the proposed method generally expands the effective reconstruction region to twice that of Ambisonics, while improving reconstruction accuracy by 32% and 12.5% within a region spanning two to three times the array radius, compared with the plane wave decomposition method.