The SoundScriber system was introduced in 1942, and was voice recording format that used a soft flexible vinyl disc onto which the sound was embossed as grooves, using vertical (or ‘hill and dale’) recording rather than lateral recording.
Two different sizes, both bright green with a square centre hole, were produced – 6 inches (known as ‘Mail Chute’) that played for fifteen minutes, and 4-inch ‘Memo Discs’ with eight minutes of recording time.
The soft vinyl meant playback was only possible a few times, but for dictation purposes this was sufficient.
SoundScriber remained popular for two decades and competed against similar formats such as the Audograph and Dictabelt.