We report here a new understanding of the mechanisms involved in the sonoelectrochemical synthesis of nanoparticles. Our results indicate that, in addition to the deposition-break processes, a suspended electrode that is formed by the ultrasonic wave has a major effect on the particles' properties. This new understanding of the sonoelectrochemical mechanisms clarifies some unsolved issues and allows for better design of sonoelectrochemical synthesis. However, we believe that the major significance of this new insight is the opening up of new possibilities for sonoelectrochemical synthesis of composite and core-shell materials.