First results of the experiments on the acoustic communication of dolphins are reported. They are complemented with the demonstration of a motor reaction of the dolphin keeping watch on the respondent, which was the same for all participants of the dialogue, i. e. turn of the head or trunk towards each other during transmission/reception of the information. The procedure allows unequivocal comparison of the acoustic signals with the behavioral acts of the animals during the experience. All stages of the animal's learning as well as oscillograms of the acoustic signals during acoustic communication behavior and echolocation process connected with differentiation of targets are shown. The routine procedure of investigating formation of the learning set served as the basic model of the physiological experiment. The non-realized action with an increasing emotional load leading on its peak to, inevitable acoustic intervention in to the respondent's work played the role of stimulus of the communication reaction, thus supporting model of communication behavior.