Individualized interaural time difference model based on spherical harmonic function expansion

On the basis of spherical harmonic expansion,a spatially continuous and individual interaural time difference (ITD) model is proposed.Correspondingly,the spatial sampling theorem of ITD is derived.Calculations of ITDs measured from 52 human subjects demonstrate that the proposed ITD model,which is represented as a weighted sum of spherical harmonics up to degree 6,is adequate to describe the spatial characteristics of ITD including left-right symmetry and front-back asymmetry.The spatially continuous ITD for a specific subject can be accurately reconstructed from 39 measured ITDs at different spatial directions,or approximately reconstructed by four headand pinna-related anthropometric parameters.The proposed ITD model is superior to existing ITD models in aspects of model structure and accuracy,and is helpful to simplification of ITD measurement as well as anthropometry-based customization of ITD.