Fig. 8. (A) The bat pulse duration (red line, no symbols, left axis in ms), pulse repetition rate (PRR; red line/circles, left axis in pulses s^–1) and 501-T3 spikes per burst (blue line/circles, right axis) for the corresponding B2 trial in Fig. 6. The top axis is distance to contact (cm). OS, out of the calibrated space. 501-T3 burst responses cease before the buzz II phase begins (indicated by the right-hand dotted line), but single-spike responses continue into the buzz II phase; these cease before contact. (B) A comparison of the bat PRR (red line/circles, in pulses s^–1) with the burst rate of 501-T3 (blue line/triangles, in bursts s^–1) to illustrate accurate following of bat vocalization emissions by 501-T3 during the stable approach phase and into the buzz I phase. Although 501-T3 continues to respond to bat vocalizations into the buzz II phase, accurate encoding of bat PRR breaks down before the transition from the buzz I phase to the buzz II phase (indicated by the decrease in 501-T3 burst rate before the buzz II phase).