Fig. 1.

Experiments were conducted with a dolphin positioned on a “biteplate” apparatus suspended under water in San Diego Bay. Emitted dolphin biosonar clicks were recorded using a hydrophone (click receiver) embedded in a suction cup placed on the melon. The dolphin’s task was to discriminate between echoes with fixed delay (non-jittering) and those with delay alternated (jittered) from one click emission to the next