Hologram interferometry was introduced in 1965 by Powell and Stetson. With a double pulsed ruby laser as light source, this technique is a very competitive tool for the study of transient events like the propagation of bending waves in plates and shells, to visualize shock waves in phase objects like air or water or just to record nice double exposure holograms of modes of vibration in optical modal analysis. In the following a number of experiments to visualize wave propagation in solids and liquids are presented