Direction-Dependent Ear Canal Transmission at High Frequencies: A Multi-Subject Study using 3D-Printed Replicas

Fourrier B, Sinev D, Pries B, Preihs S, Peissig J. Direction-Dependent Ear Canal Transmission at High Frequencies: A Multi-Subject Study using 3D-Printed Replicas. In: AVARIG 2026: Audio for Virtual and Augmented Reality and Immersive Games. Audio Engineering Society; 2026. Paper 10339. Available from: https://aes.org/publications/elibrary-page/?id=23301

@inproceedings{Fourrier2026_23301,
  author = {Fourrier, Baptiste and Sinev, Daniel and Pries, Benjamin and Preihs, Stephan and Peissig, Jürgen},
  title = {{Direction-Dependent Ear Canal Transmission at High Frequencies: A Multi-Subject Study using 3D-Printed Replicas}},
  booktitle = {AVARIG 2026: Audio for Virtual and Augmented Reality and Immersive Games},
  note = {Paper 10339},
  year = {2026},
  month = jun,
  publisher = {Audio Engineering Society},
  url = {https://aes.org/publications/elibrary-page/?id=23301}
}

TY  - CPAPER
TI  - Direction-Dependent Ear Canal Transmission at High Frequencies: A Multi-Subject Study using 3D-Printed Replicas
AU  - Fourrier, Baptiste
AU  - Sinev, Daniel
AU  - Pries, Benjamin
AU  - Preihs, Stephan
AU  - Peissig, Jürgen
T2  - AVARIG 2026: Audio for Virtual and Augmented Reality and Immersive Games
M1  - Paper 10339
PY  - 2026
DA  - 2026/06/30
UR  - https://aes.org/publications/elibrary-page/?id=23301
PB  - Audio Engineering Society
LA  - en
AB  - Head-Related Transfer Functions (HRTFs) are commonly measured at the blocked ear canal entrance, assuming that the ear canal transfer function is direction-independent. While this assumption holds well at low and mid frequencies, its validity at high frequencies has been questioned. A recent pilot study on a single pair of 3D-printed ear replicas found evidence of directional effects above 9 kHz, but was limited in scope. This study extends that work using 3D-printed ear replicas of ten subjects from the IHA database of human geometries, mounted on a dummy head. Ear canal transfer functions were measured across a full spherical grid of 1944 incidence angles. Results reveal significant directional variability above 67 kHz, with standard deviations of 47 dB at resonant frequencies. High measurement repeatability confirms these are genuine directional effects rather than measurement artifacts. The directional behavior is consistently observed across all subjects and appears linked to the second and higher ear canal resonances. These findings suggest that the current state-of-the-art blocked-canal HRTF measurements may omit spatially relevant spectral information above 67 kHz.
ER  -