Free-Field Virtual Psychoacoustics and Hearing Impairment: Paper ICA2016-53 Measurement of pinna flare angle and its effect on individualized head-related transfer functions

Head-related transfer functions (HRTFs) are essential to the researches of binaural hearing and applications of virtual auditory display. Generally, HRTFs vary with frequency as well as source position relative to head centre. They also depend on anatomical structure and parameters of individual subject. The related anatomical parameters mainly include the dimensions of head and pinnae, and the position parameters between the pinna and head. In present work, the influence of pinna flare angle on HRTFs is investigated by using numerical calculation. Based on a combination model of ellipsoidal head and laser-scanned pinnae from KEMAR artificial head, the pinna flare angle in the model is changed from an original value with displacements of 6.7 degrees, and the corresponding horizontal HRTFs at various azimuths are calculated by using boundary element method. Results indicate that the changing pinna flare angle leads to a systemic variation on the frequency and azimuthal distribution of HRTF magnitude spectra. And approximately, the variation of azimuthal distribution of HRTF magnitude spectra is linearly related to the change of pinna flare angle. Therefore, individualized azimuthal HRTF magnitudes corresponding to various pinna flare angle can be predicted or customized by applying appropriate azimuthal rotation manipulation to a set of original HRTF data with certain pinna flare angle. The method in present work is applicable to customize a matched set of HRTFs for improving the perceived performance of virtual auditory display.