Crossover Frequency Estimation From Statistical Features of a Room Transfer Function
* Presenting author
In certain practical situations one faces the problem of choosing the most suitable approach to analyze the sound field in a room. For acoustically small rooms, a modal approach is of higher importance, as opposed to acoustically large rooms, when statistical considerations provide more useful models. In the context of reverberation rooms, an important issue to be dealt with relates to the diffusion of the sound field. Although the evaluation of how close the field is from being diffuse is under discussion, it seems to be accepted that such a condition isn't reached under a crossover frequency, also referred to as the "Schroeder Frequency". This paper presents the investigation of procedures based on statistical features of rooms' Transfer Functions aiming the experimental determination of such a frequency. Real and imaginary parts of transfer function are analyzed with Kurtosis, and the phase with a proposed measure. Results from measurements performed in a large (108.5 cubic meter) and in a scaled (1.48 cubic meter) reverberation rooms are presented, as well as results from analytical solution from three shoebox rooms with the same volume, but different symmetry degree. Both measures presented comparable results, showing possible, and potentially more precise practical approaches.