A vector quantization approach for room transfer function classification

A vector quantization (VQ) technique for room acoustics applications is described. Such an approach allows classification of all possible room transfer functions (RTFs) corresponding to different source/receiver positions into discrete and representative frequency response patterns. Results are presented for simulated tests in three rectangular enclosures, for which the optimum number of such patterns (centroids) is estimated. The performance of the proposed method is also assessed by deconvolution which indicates the degree of similarity between all classified RTFs and their corresponding centroids. The VQ technique achieved the required classification in all tested cases. Typically, 256 centroids were required for a medium-sized room, resulting in approximate reduction of 20:1 over all possible RTF measurements inside such an enclosure. The VQ performance was better for central source positions than for the corner positions. In all cases RTF smoothing could be observed after deconvolution by the inverse of the centroid´s spectrum, indicating that the VQ technique is suitable for dereverberation applications