G. Yа. Shajdurov - Dr.Sc. (Eng.), Professor, Military Engineering Institute, Siberian Federal University General Director, STC of Radio Electronics "Mezon", Honored Worker of Science and Technology of Russian Federation. E-mail: GShaidurov@sfu-kras.ru
G. N. Romanova - Senior Research Scientist, Department of Radio Electronic Systems, Institute of Engineering Physics and Radio Electronics, Siberian Federal University. E-mail: gromanovakrs@yandex.ru
D. S. Kudinov - Ph.D. (Eng.), Professor, Military Engineering Institute, Siberian Federal University. E-mail: kudinovdanil@yandex.ru
G. M. Aldonin - Dr.Sc. (Eng.), Professor, Institute of Engineering Physics and Radio Electronics, Siberian Federal University. E-mail: Galdonin@sfu-kras.ru

This paper is devoted to the phenomenon of the electromagnetic and acoustic waves interaction in the ion-conducting media. In particular, theoretical evaluation of impact effects to electroconductivity of seawater by means of acoustic radiation value is given. Quantitative ratio depending on the conductivity is obtained from the kinetic theory of electrolytes. Paper describes three following components of current which occur in ion-conductive medium due to simultaneous action of acoustic and electromagnetic fields: current frequency ωe, caused by the fluid conductivity at T = T0, excluding the effect of acoustic oscillations; current at the difference frequency (ωe ? ωa); current at the additive frequency (ωe + ωa). The experiment results performed in a laboratory ultrasonic bath in the salt water in the acoustic radiation frequency of 15 kHz are presented. As used cylindrical acoustic transducer of the standard set of barium titanate elements with narrow frequency range fa = 15 kHz and 0,5 W power supplied. Electromagnetic field with a frequency fe = 16,25 kHz is excited by conductive plates. An unmodulated harmonic electromagnetic signal was used. It is shown that in all cases there is a clear effect of parametric demodulation with a parabolic growth law with increasing excitation current acoustic transduser and a significant increase with the advent of salinity of water. Taking into account the experimental data shows the potential of parametric demodulation method for underwater radio signals in seawater.