Grooved Dictation Belts
These should not be confused with the Magnetic Dictation Belts discussed here. Dictaphone made machines that used these. Another format that was used in the 1950s was the Sonoband. Steve Smolian said on 2006-08-04 that he owns a Sonoband machine in addition to his Dictaphone machines.
Resources for transferring:
grooved dictation belts: Steve Smolian, Maryland — Vidipax, New York