VOGT, HANS (189o– ), German inventor, was born on Sept. 25, 1890, at Worlitz, Bavaria, Germany. He began his career as an inventor in the sphere of high frequency technology, telephone research and earth current telegraphy. In 1918 he began to collaborate with Joseph Massolle and Dr. Engl, and this led to the fprmation of the Triergon-Arbeitsgemeinschaft, which aimed at the creation of the speaking film. On Sept. 17, 1922, the first public exhibition of the speaking film was held at the Alhambra in Berlin. The voice is photographed directly on to
the film band after conversion of the acoustic oscillations, which are taken with an inertialess microphone (kathodophone), and are changed by a photoelectric cell into light pulsations. Repro duction is effected by an electrostatic telephone with mica mem brane (statophone).