On the poor robustness of sound equalization in reverberant environments

This paper examines the sensitivity of sound equalization to source or microphone position changes in a reverberant room. It is demonstrated that even small displacements from the reference (equalization) point, of the order of a tenth of the acoustic wavelength, can cause large degradations in the equalized room response. The general theory developed in this paper, which implies that the sound equalization in practical environments may be an ill-posed problem, is verified by the simulation results averaged over different source and microphone positions.