The reproduction of virtual acoustic environments via headphones generally relies on the measurement of the acoustic propagation properties from the source position to the listener's ears, termed as Head Related Transfer Functions (HRTFs).Instead of every possible source positions, HRTFs are usually measured on a sparse spherical, or circular grid at a fixed source-listener distance. The application of WFS theory for estimating HRTFs outside the measurement grid has been proposed already in the related literature. Recently a generalized WFS theory has been introduced by the present authors that theoretically may allow amplitude correct and aliasing-free synthesis at the listener position. The present study investigates the performance of the generalized Wave Field Synthesis theory when applied for HRTF interpolation and extrapolation. Quantitative comparisons are given with the reference solution based on boundary element simulations.