Microphone array optimization by stochastic region contraction

The authors deal with optimal microphone placement and gain for a linear one-dimensional array often in a confined environment. A power spectral dispersion function (PSD) is used as a core element for a min-max objective function (PSDX). Derivation of the optimal spacings and gains of the microphones is a hard computational problem since the min-max objective function exhibits multiple local minima (hundreds or thousands). The authors address the computational problem of finding the global optimal solution of the PSDX function. A new method, stochastic region contraction (SRC), is proposed. It achieves a computational speedup of 30-50 when compared to the commonly used simulated-annealing method. SRC is ideally suited for coarse-gain parallel processing