3D reconstruction of HRTF-fields from 1D continuous measurements

Head-related transfer functions (HRTFs) describe direction and distance dependent receiver characteristics of the human head and the outer ear. They are a central tool in binaural sound technology and their fast and accurate acquisition in all dimensions therefore requires further attention. In this paper, we make use of a recently proposed technique for quasi-continuous head-related impulse response (HRIR) measurements on the azimuth circle of the auditory sphere. We then apply Fourier acoustics to achieve range extrapolation of the obtained HRIR data. Here, the advantage of using almost continuous data in contrast to a discrete representation of the auditory sphere is twofold. On the one hand, we can reduce or ideally avoid the effect of spatial aliasing related to HRTF/HRIR interpolation, while on the other hand, direct and robust calculation of Fourier integrals on an almost closed contour is enabled. Based on cylindrical coordinates, we first develop the framework for 2.5D reconstruction of HRTF-fields with bias, whereas in spherical coordinates we eventually demonstrate unbiased 3D reconstruction of HRTF-fields from the 1D continuous data.