Probability of responses to the right as a function of ITD at frequencies ≥2000 Hz. The left column shows the performance using virtual headphones. The right column shows the free-field performance depending on the ITDs occurring in the free-field experiments.

<p>Tones with frequencies of 2000 [n = 6 (vhp, free-field)], 2400 [n = 5 (vhp) and 4 (free-field)], 2673 (n = 5, vhp only), 2900 Hz (n = 5, vhp only), and 3000 Hz (n = 6, free-field only) were presented. Symbols and lines as in the previous figure. Thresholds (in μs) and identifiers of individual animals are given on the right. ‘x’ indicates that no threshold could be determined because the threshold criterion was not reached. Thresholds in brackets were derived from cumulative normal distribution functions that yielded R²<0.875 with the raw data and not used in further analyses; such cumulative normal distribution functions are not shown.