Analysis on the spatial symmetry of head-related transfer function

Methodsfor analyzing the spatial symmetry of Head-Related Transfer Function(HRTF)are proposed.The influences of anatomical structures on the symmetry of HRTF are investigated using HRTFs measured on KEMAR mannequin and human subjects.Resultsshow that for KEMAR mannequin,pinnae destroy the front-back symmetry of HRTF above 5~6 kHz,while for human subjects it reduces to 2.5 kHz because of the locations of ears.Furthermore,at low and median frequencies,HRTF is approximately left-right symmetrical.While as frequencies increase,the asymmetry caused by the fine anatomical left-right differences appears.The starting frequency and the extent of the left-right asymmetry in HRTF depend on individuals.The analyses can demonstrate the spatial symmetrical characteristics of HRTF,and the frequency ranges in which current binaural models are valid