Lev Sergeyevich Termen ( – 3 November 1993), or
Léon Theremin in the
United States, was a
Russian and
Soviet inventor, most famous for his invention of the
theremin, one of the first
electronic musical instruments and the first to be
mass produced. He also devised the
interlace technique for improving the quality of a video signal, still widely used in video and television technology. His listening device, "
The Thing", hung for seven years in plain view in the United States Ambassador's Moscow office and enabled Soviet agents to eavesdrop on secret conversations. It is considered a predecessor of
RFID technology.