Photograph of the actress Norma Shearer during sound recordings on the telegraphone at the MGM studio

Until the end of the Second World War, the magnetic sound recording method remained a niche application. Wire recording devices were hardly ever found in private households and only rarely in companies. The main customers were government authorities, particularly military and intelligence services. In 1927, the movie "The Jazz Singer" premiered, and the era of movies with sound began. Norma Shearer, a Hollywood actress already known in the silent movie era, used the telegraphone for test recordings in order to continue her career in "talkies."