New technical possibilities continually arise from theoretical studies. However, transposing promising laboratory experiences into industrial applications is only possible with powerful, simple, and good efficiency transmitters. Research is being pursued and has already given interesting results. Among other aims, they specially concern: 1. A friction loudspeaker of long service high acoustical power with high efficiency. 2. A spark generator producing very high peak power pulses for a few microseconds. This device would have to be used for dislocation.