The idea of combining recording sound with picture is nearly as old as film itself, although restraints imposed by technology made this possible only in the 1920s with the introduction of the Vitaphone system. Used on features and nearly 2,000 short subjects by Warner Bros. and its sister studio First National from 1926 to 1930, Vitaphone was the most successful of the sound-on-disc processes.
Rather than the picture and audio co-existing on the same film, the soundtrack was issued separately on 16″ phonograph records. Using projectors, amplifiers and speakers enabled simultaneous playback of both audio and picture – this was achieved by aligning a start mark on the film with the picture gate whilst at the same time placing a phonograph record on a turntable and aligning the phonograph needle with an arrow scribed on the record’s label. When the projector rolled, the phonograph would turn at a fixed rate of 33 1/3 r.p.m. to match the 11-minute maximum playing time of a reel of film and, in theory, picture and audio would play back in sync. Unlike most phonograph discs, the needle on Vitaphone records would move from the inside of the disc to the outside.
Towards the end of the 1920s, the studio system further strengthened the relationship between picture and audio and saw the Radio Corporation of America (RCA) move into the movie business in an effort to exploit the RCA Photophone – a technology owned by RCA’s parent company, General Electric. The Photophone was a sound-on-film “variable-area” film exposure system that allowed electrically-recorded audio to be synchronised to a motion picture image.
While the “variable-area” format saw competition in the form of “variable-density” systems, neither was perceived to be significantly superior and indeed both systems were marketed equally by RCA and another company, Western Electric. Ultimately, the RCA systems were abandoned and the Western Electric (Westrex) system was renamed Photophone after the Western Electric and Westrex registered trademarks were sold for use in cinema sound systems. Renaming of the Westrex system to Photophone was facilitated by the demise of RCA’s cinema sound business unit and by General Electric’s failure to secure the Photophone trademark. Although technology has now moved on considerably, the Photophone system is still in production, with more than 100 systems currently in active service world-wide.
Of course, sound for picture has become inherently more efficient and simultaneously more complex with the advancement of digital tools for audio creation. With large post-production facilities at hand and with the development of non-destructive editing, producers have far more options and tools available to them to create some phenomenal soundscapes for picture. Arguably one of the most creative professions for the audio engineer, audio post-production requires a wide range of skills and often involves teams specialising in various stages of production, from initial audio capture to post-production Foley and ADR recording to editing and, finally, mixing and mastering to any one of many digital multi-channel formats.