A new HRTF interpolation approach for fast synthesis of dynamic environmental interaction

For real-time immersive virtual auditory spaces, a realistic rendering of moving sound sources with no noticeable discontinuities is of valuable importance. Therefore binaural synthesis of the time-varying sound field is performed by updating a dense grid of headrelated transfer functions (HRTFs). Unless the lowest directional resolution for sampling HRTFs is sufficiently small, direct switching between them will cause an audible artifact that is heard as a click. To avoid this problem and ensure the availability of enough HRTFs. the authors propose a new binaural impulse-response interpolation algorithm based on the solution for the rational minimal state-space interpolation problem. Motivated by the resulting outstanding interpolation accuracy, and in view of reducing the overall synthesis time, the authors first reduced the HRTF length using principal component analysis (PCA) before applying the new rational interpolation method. Compared with existing interpolation techniques, this method allowed a fast and very precise reconstruction of HRTFs. and insured an immersive high-fidelity virtual auditory space.