  The role of sound in the dynamics of mesoscale systems is typically
neglected, since frequently the associated time scales are much smaller than
all the other time scales of interest. However, for sufficiently small objects
embedded in a solvent with a sufficiently small sound velocity, sound can play
a crucial role. In particular, behavior resembling viscoelasticity has been
theoretically predicted for non-viscoelastic fluids. This effect is due to the
interference of the propagation of sound waves caused by the solute particle's
motion and hydrodynamic vortex formation. We demonstrate this effect, known as
backtracking, in computer simulations employing the method of multiparticle
collision dynamics. We systematically study the influence of sound on the
dynamics of the solute particle, and find that it disappears in the long-time
limit. Thus, we confirm that sonic effects at the single-particle level can be
neglected at sufficiently long times.
