Differences between individualized and non-individualized HRTFs.

We tested for each owl and stimulus azimuth whether the head-turn angles differed between HRTFs with intact ruff (owls H and S: individualized; owl P: HRTFs of owl H) and HRTFs of owl 39 normal, respectively owl 39 ruffcut (Wilcoxon signed ranks test, p<0.05). The frontal field (≤±60° stimulus azimuth), a position in the middle field (±100°) and in the periphery (±140°) were regarded separately. Differing positions are also marked with blue asterisks (owl 39 normal) and red asterisks (owl 39 ruffcut) in Figure S4. The first number in each column gives the number of pairings where the mean turning angles were not significantly different; the second number is the total number of tested pairings. The percentage is given in brackets. There were highly significantly (Fisher test, p<0.001) more differences at ±140° in the owl 39 ruffcut condition than in the owl 39 normal condition, but not in the frontal field.