Optimal Series Truncation of the Rigid-Sphere Head-Related Transfer Function for Accurate Binaural Perception

Sridhar R, Choueiri EY. Optimal Series Truncation of the Rigid-Sphere Head-Related Transfer Function for Accurate Binaural Perception. J Audio Eng Soc. 2021;69(5):340-350. doi:10.17743/jaes.2021.0007

@article{Sridhar2021_21038,
  author = {Sridhar, Rahulram and Choueiri, Edgar Y.},
  title = {{Optimal Series Truncation of the Rigid-Sphere Head-Related Transfer Function for Accurate Binaural Perception}},
  journal = {Journal of the Audio Engineering Society},
  volume = {69},
  number = {5},
  pages = {340--350},
  year = {2021},
  month = may,
  publisher = {Audio Engineering Society},
  doi = {10.17743/jaes.2021.0007},
  url = {https://doi.org/10.17743/jaes.2021.0007}
}

TY  - JOUR
TI  - Optimal Series Truncation of the Rigid-Sphere Head-Related Transfer Function for Accurate Binaural Perception
AU  - Sridhar, Rahulram
AU  - Choueiri, Edgar Y.
T2  - Journal of the Audio Engineering Society
J2  - J. Audio Eng. Soc.
VL  - 69
IS  - 5
SP  - 340
EP  - 350
PY  - 2021
DA  - 2021/05/06
DO  - 10.17743/jaes.2021.0007
UR  - https://doi.org/10.17743/jaes.2021.0007
PB  - Audio Engineering Society
LA  - en
AB  - A formula is derived for computing the order at which the infinite series representation of the rigid-sphere head-related transfer function (RS-HRTF) must be truncated to minimize the time required to compute the HRTF to a sufficiently high accuracy based on binaural perception metrics. Quick and accurate computation of this HRTF may be useful for implementing spatial audio in computationally limited and portable devices. Using a brute-force approach, the lowest truncation order, Nmin, that yields the RS-HRTF that differs from the benchmark (i.e., the RS-HRTF computed with the highest possible accuracy) by less than just-noticeable difference thresholds in interaural time and level differences is approximately computed for a wide range of source distances. By fitting power and rational functions to these computed values, a formula that approximates Nmin as a function of frequency and source distance is derived. It is shown that truncation order varies significantly with source distance and that the proposed formula, unlike a previous one, accurately captures this variation. Consequently, using the proposed formula instead of the previous one results in a more accurate RS-HRTF that is also computed 48% faster on average.
ER  -