Head-related transfer function filter interpolation by root displacement

Head-related transfer function (HRTF) filters are used in virtual auditory displays for the binaural synthesis of the direction of a sound source over headphones. Once low-order HRTF filters are designed, the interpolation of these filters becomes an important issue for the synthesis of moving sound sources. An HRTF filter interpolation method based on the displacement of HRTF filter roots is proposed. It is possible to obtain a minimum-phase interpolated filter given that the original filters are also minimum-phase. The computational complexity of the method is the lower than that of the linear interpolation of magnitude responses.