Model order selection for estimation of Common Acoustical Poles

Common acoustical poles provide a convenient way of modeling different Room Transfer Functions relative to the same environment, by retaining the resonant properties of the room itself under the form of common auto-regressive coefficients; different methods have been proposed to estimate the latter, but all need an order to be priorly established. Although, for a few room geometries, a theoretical order can be computed, actual usable values (always much smaller) may depend on the particular chosen estimation configuration, and no specific method is available for their determination. In this work, a novel empirical technique to select an appropriate model order is presented. This technique is tested in a simulated environment and the results are presented, compared to the theoretical values.