  The existing viscous and incompressible theory of isothermal sound
propagation and attenuation in suspensions considers solid particles which are
infinitely viscous. We extend the theory by applying the amended Coriolis
flowmeter "bubble theory". Here, the drag force is a function of both the fluid
and particle Stokes numbers and the particle-to-fluid ratio of the dynamic
viscosity [V.Galindo and G.Gerbeth, A note on the force of an accelerating
spherical drop at low-Reynolds number, Phys. Fluids A Vol. 5, 3290-3292
(1993)]. Aerosol and hydrosol examples are presented and differences between
the original and extended theories are discussed.
