The Selfear project: a mobile application for low-cost pinna-related transfer function acquisition

Virtual and augmented reality are expected to become more and more influential even in everyday life in the next future; the role of spatial audio technologies over headphones will be pivotal for application scenarios which involve mobility. This paper faces the issue of head-related transfer function (HRTF) acquisition with low-cost mobile devices, affordable to anybody, anywhere and possibly in a faster way than the existing measurement methods. In particular, the proposed solution, called the SelfEar project, focuses on capturing individual spectral features included in the pinna-related transfer function (PRTF) guiding the user in collecting non-anechoic HRTFs through a selfadjustable procedure. Acoustic data are acquired by an audio augmented reality headset which embedded a pair of microphones at listener ear-canals. The proposed measurement session captures PRTF spectral features of KEMAR mannequin which are consistent to those of anechoic measurement procedures. In both cases, the results would be dependent on microphone placement, minimizing subject movements which would occur with human users. Considering quality and variability of the reported results as well as the resources needed, the SelfEar project proposes an attractive solution for low-cost HRTF personalization procedure.