A Voice in the Air
In 1893 Professor Reginald A. Fessenden, a native of Quebec, Canada, came to Pittsburgh to serve as the head of the electrical engineering department at Western University (now the University of Pittsburgh.) While here, Fessenden read of the radio experiments that Guglielmo Marconi was conducting in England and began experimenting himself at a lab at Allegheny Observatory. Marconi’s system could only transmit and receive dots and dashes—Morse code. But Fessenden’s goal was to transmit the human voice and music.
To accomplish this he devised the theory of the "continuous wave"—a means to superimpose sound onto a radio wave and transmit this signal to a receiver where the radio wave would be removed, leaving the listener with the original sound. (The continuous wave is the electronic basis that makes radio and television transmission possible.) Fessenden later put the theory into practice and made the first long-range transmissions of voice on Christmas Eve 1906 from a station at Brant Rock, Massachusetts. It is said that ship radio operators hundreds of miles out in the Atlantic heard the program.
Although Fessenden’s work made voice radio possible, it would take ten years and the First World War before it became commonplace. Throughout this period, radio was still seen primarily as point-to-point communication between transmitting stations—a sort of "wireless telephone." The notion of "broadcasting" or transmitting to an audience of listeners was not seen as practical. Radio at that time was used mostly for commercial shipping purposes, but land-based amateur operators began to appear as electronic technology improved.