![poster](https://image.tmdb.org/t/p/w300/mbF9tIkUdOLVWbWrrVveIN7xzsT.jpg)
Patent Nr. 314805
Documentary
2020
2
Finnish engineer Eric Tigerstedt solved the dilemma of sound-on-film already before the First World War. All images and sounds in this short film are produced from the surviving test materials originally created in 1914.