The paper concerns with mathematical modeling of two-velocity media with reference to data on Stoneley wave propagation at the fluid-porous solid interface from experiments by K.W. Winkler, H.L. Liu, and D.J. Johnson. Models obtained within the limits of two theories, that of Biot (Biot–Johnson) and continuum filtration, are investigated in comparison. On this basis, it is discussed whether it is reasonable to include pore tortuosity and frequency-dependent permeability and tortuosity when modeling the mechanics of deforming fluid-saturated porous solids.