On the use of the scaled spherical wave expansions for recovering the target sound field in non-anechoic spaces

The scaled spherical wave expansion (SSWE) method was effectively applied to reconstruct the target sound field from measurements conducted in non-anechoic environments. Unlike traditional spherical wave expansion (SWE), which requires careful selection of the optimal cutoff order to balance accuracy and computational efficiency, the SSWE approach eliminates this challenge by introducing a scaling factor that adjusts the expansion coefficients. In addition, a simplified formulation was developed specifically for target sources with rigid surfaces, further enhancing the method’s practicality. Numerical simulations were conducted to validate the proposed method, confirming its effectiveness in accurately reconstructing sound fields under various conditions. A comparative analysis between the scaled and non-scaled SWEs revealed that the SSWE method significantly improves computational efficiency while maintaining high accuracy. Furthermore, the study investigated the influence of the scaling surface radius on the reconstruction performance and established a practical selection rule to optimize this parameter. These findings highlight the advantages of the SSWE method in sound field reconstruction, particularly in non-ideal acoustic environments where traditional methods may face limitations. The proposed method offers a more efficient and robust solution for practical applications in acoustical engineering and noise control.