Low-order modeling and grouping of HRTFs for auralization using wavelet transforms

An efficient method for modeling head-related transfer functions (HRTFs) of an auralization system is presented. The proposed model is based on the decomposition of the impulse response of the HRTFs by wavelet transforms and on the grouping of such functions for close directions. Through an analysis of the HRTF energy content per subband, it is shown how the model can be reduced without introducing considerable errors in the magnitude and phase frequency responses. As a result of the proposed technique, a significant reduction in the processing time of the auralization process is obtained by a low-order model which has approximately 30% of the number of coefficients of the original HRTF and by a reduction in the number of HRTF directions to less than 10%.