Ediphone Master Shaver, circa 1940

Dictaphones and Ediphones were sound recording devices largely used for oral dictation in business settings. In this scenario, wax cylinder recordings were passed to a secretary, who listened to the recording with a playback-only transcriber and then typed up notes. A shaving machine, such as this one, scraped the previously inscribed layer away allowing a wax cylinder to be reused over 100 times.