Within the framework of isothermal approximation, the effect of local mass displacement on mechanical and electromechanical wave processes is studied in non-ferromagnetic polarized solids. The dispersion properties of the longitudinal plane elastic harmonic wave, Rayleigh wave, and non-plane surface shear wave (SH wave) are analyzed. It is shown that unlike the classical theory, these waves become dispersive in the local gradient theory of dielectrics.