  Generation of an acoustic wave by two pump sound waves is studied in a
three-phase marine sediment that consists of a solid frame and the pore water
with air bubbles in it. To avoid shock-wave formation the interaction is
considered in the frequency range where there is a significant amount of sound
velocity dispersion. Nonlinear equations are obtained to describe the
interaction of acoustic waves in the presence of air bubbles. An expression for
the amplitude of the generated wave is obtained and numerical analysis of its
dependence on distance and on the resonance frequency of bubbles is performed.
