Recognition of classes of noise-like signals by dolphins Tursiops truncatus

The ability of the auditory system to perceive and to classify the noise-like signals imitating natural sea noises has been studied in dolphins Tursiops truncatus. Results of the studies carried out in a sea bay at free movement of the animals have shown that dolphins are able to determine noise-like signals and to ascribe them to a certain class by using invariant characters, such as rhythmical sequence of impulses, regardless of the frequency-time scale of the signal presentation.