[The structural characteristics of the echolocation signal in the beluga whale Delphinapterus leucas].

The sounding signal analysis of beluga dolphin under aquatory adaptation with orientation reflexes has been conducted. It has been shown that the single sounding orientation impulse of beluga has a complex structure. Its initial part consists of a large number of components and has a great power. The main part of impulse is frequency-modulated and has a large duration and constant amplitude. The spectral analysis of beluga's signal demonstrates the low-frequency character with spectrum maximal of 1.6 kHz.