Representation and comparison of HRTF in spatio-temporal frequency domain

We represent a head-related transfer function (HRTF) in the spatio-temporal frequency domain. Since an HRTF is defined as an acoustic function of time and location of sound source, the spatio-temporal frequency characteristics of HRTFs can be visualized and analyzed by multi-dimensional Fourier transform in time and space. In our experiments, we investigate a basic property of the spatio-temporal frequency characteristic and the difference between HRTFs obtained by numerical analysis and actual measurements. The influences caused by pinnae for the spatio-temporal frequency characteristic are also examined. It is found that the spatio-temporal spectral components are mostly concentrated in specific frequency bands, and these components are different in each measurement condition.