Fig. 2.

Directional filters derived from principal components analysis of rabbit directional transfer functions. A: magnitude spectra of the left (dashed line) and right (solid line) directional filters at +90° (positive sign indicates right). Magnitude spectra have the shape of the first principal component basis function, p₁(f). B: ILD weight of the first principal component vs. azimuth, with sinusoidal fit (curve). C: ITD at 1.5 kHz between left and right rabbit head-related transfer functions, with sinusoidal fit (curve). D and E: ILDs and ITDs, respectively, across frequency for directional filters used in the present study. From top to bottom, directional filters correspond to +90°, +75°, …, −90° azimuth.