Interpolation of Head-Related Transfer Functions (HRTFS): A multi-source approach

This paper proposes a new method for the interpolation of Head-Related Transfer Functions (HRTFs) applied to the generation of 3-D binaural sound, especially when dealing with moving sound sources indoors. The method combines a modified linear interpolation strategy with a representation of the auditory space based on spatial characteristic functions (SCFs), previously known from the literature. The main idea here is to associate the low complexity the SCF-based representation yields in the multi-source case with the inherent simplicity of the linear interpolation. Complexity issues are discussed. The performance of the proposed method is evaluated against the direct bilinear interpolation of HRTFs, using Spatial Frequency Response Surfaces (SFRSs).