The Tefifon is an audio playback format, developed and manufactured in Germany, that utilizes cartridges loaded with an endlessly looped reel of plastic tape.

A few years earlier, devices using phonographic grooved tape like the Tefifon were produced by Tefi for special purposes, like the military, and were designed for voice recording.

In 1937, a half-speed 9.5 CPS (3-3/4 IPS) format was developed for talking books for the blind in the early run-up to World War II.

With no way to get an eight-hour recording done all in one session with no mistakes, these extremely long programs were transcribed first onto 15-minute cartridges (30 minutes of Talking Book) and later 1-hour cartridges (2-hour Talking Book) and then assembled by playing them back in succession much as a long radio program is spread over many sides and assembled later on-air to sound as if the whole thing is live.

The first Tefifon players and cartridges for home use came available in the German market towards the end of the 1940s, but could not compete with the popular phonographic disc format readily already available at the time.

The chassis of the radio sets were often purchased ready-made from third parties, with a Tefifon playback transport being added to it as a finished product.