Recently, a complete formulation of the transient surface excitation problem for piezoelectric materials has suggested the existence of a type of electrical sources on the surface not traditionally considered in piezoelectric transduction. This letter shows that these additional sources correspond to electric current dipoles. It is shown that the wave forms, or the frequency dependence, of waves generated by these sources are different from those generated by traditionally studied sources such as mechanical stresses and electric currents. These characteristics can be used to identify the contribution of such sources. Schottky andp‐njunctions on the surface of a semiconductive material are suggested as the experimental implementation of the new sources. In addition to piezoelectric transduction, current dipoles can also be used to generate electromagnetic waves in a nonpiezoelectric medium. ©1995 American Institute of Physics.