Theory and Design of Multizone Soundfield Reproduction Using Sparse Methods

Multizone soundfield reproduction over an extended spatial region is a challenging problem in acoustic signal processing. We introduce a method of reproducing a multizone soundfield within a desired region in reverberant environments. It is based on the identification of the acoustic transfer function (ATF) from the loudspeaker over the desired reproduction region using a limited number of microphone measurements. We assume that the soundfield is sparse in the domain of planewave decomposition and identify the ATF using sparse methods. The estimates of the ATFs are then used to derive the optimal least-squares solution for the loudspeaker filters that minimize the reproduction error over the entire reproduction region. Simulations confirm that the method leads to a significantly reduced number of required microphones for accurate multizone sound reproduction, while it also facilitates the reproduction over a wide frequency range. Practical experiments are used to verify the sparse planewave representation of the reverberant soundfield in a real-world listening environment.