Head related transfer function representation of directional sound for spatial acoustic events modeling

This article describes the representation of spatial sound using a limited number of HRTFs. The HRTFs are significant functions for generating 3D sounds for immersive audio systems. The HRTFs, however, are not only functions of sound arrival directions but are also variable due to listeners' individual differences. Thus generation of the individual HRTFs using a few HRTF data records is desired. This report investigates a possibility in generating HRTFs for an individual subject from a database and a limited number of measured individual HRTFs. The estimation errors which are observed in the generated HRTFs can be evaluated by the signal to deviation ratio (SDR). A present example using 4 subjects' HRTFs shows that individual HRTFs in the horizontal plane can be synthesised with SDR greater than about 6 dB. Sub-band analysis/synthesis for the HRTFs is under study.