Transfer–Function–Interpolated Control–Point augmentation for diffuse acoustic field synthesis

Abstract

In the automotive, aerospace, and architectural acoustics fields, diffuse acoustic fields are employed to assess sound transmission through various materials. In the context of diffuse acoustic field synthesis using loudspeaker arrays, the conventional approach relies on establishing control points within the target area and measuring transfer functions between the loudspeakers and these points to optimize driving signals. This approach, however, guarantees accuracy only at the control points and results in increased errors elsewhere, while also requiring extensive transfer-function measurements. To enhance the global synthesis accuracy and reduce the measurement effort, we propose a statistical pressure-matching method enhanced by control-point augmentation with transfer-function interpolation. The proposed method increases the density of refined control points within the target region and employs a loudspeaker acoustic model to interpolate transfer functions throughout the entire synthesis area. The loudspeaker’s sound radiation is modeled as distinct pairs of monopole sources, positioned at segmented acoustic centers based on amplitude attenuation and phase delay. Experimental validation conducted with a 1D loudspeaker array in an anechoic chamber demonstrates that this approach achieves improved synthesis accuracy across the entire target region compared to traditional control-point-based methods, while substantially reducing the required number of transfer-function measurements.