Calibration of measured head-related transfer function database

Some causes and those effects on measurement error of head-related transfer functions (HRTFs) were analyzed. Among different causes of error on HRTF measurement, change of exact location of a listener and corresponding position change of eartips are the most important. The measurement error caused by change of position of a listener and eartips makes notable discontinuities of HRTF in space-frequency domain. For reducing discontinuity of measured HRTF, a method of using moving average and bilinear interpolation was proposed. By introducing a proposed method, detailed spectra which consist of notches and peaks are remained but smoothness of variation of HRTF with respect to change of polar angle is compensated. After applying a proposed calibration method to HRTF with discontinuities, resultant of spectra is well-matched to those of exactly measured HRTF, and the matching-improvement is about 4dB in terms of spectral distortion.