Figure 4.

Variation in sonar call durations with target distance and pulse interval in a real oscillating target tracking trial. A, The close coupling between sonar call duration and target distance is highlighted in an oscillating target trial. Target distance (gray diamonds) and call durations (black circles) are shown as a function of trial time (0–12 s). B, Sonar call duration versus pulse interval for all 1392 calls in Figure 3C. Pulse interval varies over a wide range during both real oscillating target tracking and free-flight trial conditions. The exponential relationship between call duration and PI is made clear in this semi-log plot.