The magnitude of magnetostriction of a ferromagnetic material largely determines the efficiency of electromagnetic-acoustic transformation and the intensity of magnetoacoustic emission, which are based on the application of alternating magnetic fields. This study shows that laser interferometry allows dynamic magnetostrictive behavior to be measured in an alternating magnetic field. Experiments reveal that dynamic magnetostrictive sensitivity determined from the amplitude of the second harmonic of elastic vibrations in ferromagnetic materials correlates with the value of the maximum magnetostrictive elongation of the studied ferromagnetic materials.