关键词: 头相关传输函数, 多重散射, 多极展开, 微扰法

Abstract:

Proposed in this paper is a combination of the perturbation method and the muhipole expansion method, which is used to approximately calculate the near-field head-related transfer function （HRTF） of the snowman model and to quantitatively analyze the effects of torso scattering and reflection on HRTF. Calculated results indicate that the contribution of torso scattering to HRTF depends on not only the order and frequency of perturbation app- roximation but also the position （including the direction and the distance） of sound source; that, under the first- order perturbation approximation, the contribution of torso scattering increases with the increase in both the frequency and the azimuth of the sound source departing from the ear, and with the decrease in both the distance of the sound source from the head center and the elevation of the sound source ; that the contribution of perturbation terms with higher orders to HRTF greatly decreases with the increase in perturbation orders; and that, when the sound source distance is not less than 0. 02m and the elevation is not less than 135°, the calculation errors of the third-order perturbation approximatation are controlled within ± 1.0 dB below 20 kHz, and the contributions of the fourth-order and the higher-order scatterings are neglectable.

Key words: head-related transfer function, multiple scattering, muhipole expansion, perturbation method