The static light scattering method is used for the detection of acoustic waves induced in colloidal crystals and liquids by low-frequency electric pulses, The method is sensitive to both density and shear modes and can be applied for the study of the liquid-crystalline phase transitions, At low fields the variations of light scattering intensity follow both the amplitude and the phase variations of the wave motion and enable the determination of resonance parameters, hence of viscoelastic parameters of the colloidal system.