1928 - 1932
The Tri-Ergon sound-on-film system was patented from 1919 on by German inventors Josef Engl, Hans Vogt and Joseph Massolle.
The name Tri-Ergon was derived from Greek and means 'the work of three.' A subsidiary, Tri-Ergon Musik AG of Berlin, made commercial phonograph records for the German, French, Swedish and Danish markets from about 1928 to 1932.
Although the product was advertised as 'Photo-Electro-Records,' it is unknown whether the sound-on-film process was actually used in making them, perhaps for simple cutting of the record".