Berliner, BUR luh nuhr, Emile (1851-1929), invented a practical telephone transmitter in 1877. In 1887, he also developed the first successful phonograph that used disc-shaped records. Berliner developed a telephone transmitter in which sound, such as that made by the human voice, varied the strength of an electric current. These variations caused a telephone receiver to reproduce the original sound. Berliner also invented a way to press duplicate records from one master disc (see Phonograph).