Analysis on the stability of spatial interpolation schemes for head-related transfer function

• Published in: The Journal of the Acoustical Society of America Vol. 131; no. 4_Supplement; p. 3305
• Main Authors: Liu, Yang, Xie, Bosun
• Format: Journal Article
• Language: English
• Published: 01.04.2012
• ISSN: 0001-4966; 1520-8524
• DOI: 10.1121/1.4708357

Head-related transfer functions (HRTFs) are transfer functions from sound source to two ears. They vary as continual functions of source direction. Usually, measurement yields the HRTFs at discrete directions, and HRTFs at unmeasured directions should be estimated by spatial interpolation. There are several familiar interpolation schemes, such as adjacent linear interpolation, the global interpolation, bilinear interpolation and spherical-triangular interpolation. In practice, potential subject's head movement in HRTF measurement may result in error in measured HRTFs, which may in turn deteriorate the interpolation performance. In present work, the performances for interpolation schemes against the error caused by slight head movement in HRTF measurement are evaluated and compared. The results indicate that overall, global interpolation scheme is superior to others in terms of signal-to-distortion ratio in interpolated HRTFs when undergoing a slight head movement in HRTF measurement. Taking advantage of the analog relationship between HRTF spatial interpolation and signal panning or mixing methods for multi-channel sound, the present analysis can also be extended for evaluating the signal panning methods for multi-channel sound.