Round robin comparison of inter-laboratory HRTF Measurements : Assessment with an auditory model for elevation

Repeatability of head-related transfer function (HRTF) measurements is a critical issue in intra- and inter- laboratory setups. In this paper, simulated perceptual variabilities of HRTFs are computed as an attempt to understand if different acquisition methods achieve similar results in terms of psychoacoustic features. We consider 12 HRTF independent measurement sets of a Neumann KU-100 dummy head from the international round-robin study Club Fritz. Our analysis of HRTF variabilities focuses on localization performance in elevation within the mid-sagittal plane. A round robin evaluation is performed by means of an auditory model which is able to predict elevation errors and front-back confusion for a given pair of target and template HRTF sets. Results report comparable localization performances between four HRTF databases, suggesting that these acquisition methods led to similar performances in providing elevation cues. Such findings further emphasize the intrinsic complexity and the sensitivity of the HRTF measurement process. The final aim of this study is to certify the quality and repeatability of a measurement process at perceptual level; this findings could be extended to the acquisition of human head acoustics.