[Dynamics of heart rhythm in chimpanzees during the perception of the emotionally colored human voice].

The performed study allowed to observe in two chimpanzees both common and individual changes of the heart rate under the action of human voice with emotionally positive or negative intonation, as well as under the action of preferred (sweet) or rejected (quinine solution) natural stimulus. The common property consists in a significant slowing down of the heart rate in response to negative vocal signal and rejected natural stimulus and in only slight change of the heart rate in response to positive signals. Individual properties comprise differences in reactions of the cardiovascular system of both animals to negative action: a greater efficiency of the vocal signal for one chimpanzee and of the direct (natural) stimulus for the second one.