Design of subband notch filters based on parametric models of head-related transfer functions and comparison with actual measurements

Acoustic simulations, such as the finite element method (FEM), can be used to calculate the Head-Related Transfer Function (HRTF) from an individual's head geometry. However, calculating HRTFs with FEM incurs a significant computational cost. This study proposes a method to reduce this cost while efficiently approximating high-resolution HRTFs. In the proposed method, a low-resolution frequency response is calculated using FEM, and the perceptually important spectral notches are approximated using subband notch filters based on a parametric HRTF model. The combination of these two components reproduces the steep spectral changes characteristic of the notch bands. To verify the effectiveness of the method, its approximation accuracy was quantitatively evaluated by comparing the HRTFs approximated by the proposed method with those obtained from high-resolution FEM and actual measurements.