Listening-area-informed sound field reproduction based on circular harmonic expansion

A sound field reproduction method that exploits prior information on listening areas is proposed. Most current methods are aimed at reproducing the sound field over the entire space or around listener locations. We formulate the objective function for this problem as the expectation minimization of the spatial squared error of the sound pressure inside the listening areas. The optimal driving signals are obtained by circular harmonic expansion. Comparing the proposed method with the mode-matching method, the advantage of the proposed method appears in the optimal weighting matrix of the circular harmonics, which depends on the location and range of the listening area. Numerical simulations indicated that high reproduction accuracy compared with other current methods can be maintained in the listening areas at high frequencies by using the proposed method.