B.D. Zaitsev – Dr. Sc. (Phys.-Math.), Professor, Head of Laboratory of Physical Acoustics, Saratov branch of Kotel'nikov IRE of RAS

E-mail: zai-boris@yandex.ru

A.A. Teplykh – Ph. D. (Phys.-Math.), Senior Research Scientist, Laboratory of Physical Acoustics, Saratov branch of Kotel'nikov IRE of RAS

E-mail: teplykhaa@mail.ru