The Tri-Ergon sound-on-film system was developed from around 1919 by three German inventors, Josef Engl (1893–1942), Joseph Massolle (1889–1957), and Hans Vogt (1890–1979).
The system used a photoelectric recording method and a non-standard film size (42mm) which incorporated the soundtrack with stock 35mm film. With a Swiss backer, the inventors formed Tri-Ergon AG in Zurich and tried to interest the market with their invention.
The Tri-Ergon system appeared at a time when a number of other sound film processes were arriving on the market, and the company soon merged with a number of competitors to form the Tobis syndicate in 1928, joined by the Klangfilm AG syndicate in 1929 and renamed as Tobis-Klangfilm by 1930. While Tri-Ergon became the dominant sound film process in Germany and much of Europe through its use by Tobis-Klangfilm, American film companies were still squabbling over their respective patents. For a time Tri-Ergon successfully blocked all American attempts to show their sound films in Germany and other European countries, until a loose cartel was formed under an agreement in Paris in 1930.