CassetteMaster is a frequent YouTube poster, sharing his many analog tape machine finds. He's adept at getting them working, and equally adept at finding some rather obscure machinery. This video shows off the Dormiphone, an early endless loop tape machine (similar to the later 8 track format). There's a clock on the face of the Dormiphone with lots of switches. This was to set the timings of automated playback throughout the day, much like an appliance timer that turns lights on and off when you go on vacation.
He says the machine is likely from the 50's, and was probably intended to loop short phrases for the subject to memorize while they sleep. In a fascinating footbote, there is also some evidence that machines like these were used for ESP and mental telepathy research. In the video he plays back an original tape that he found with the machine. The delivery of the person testing out the recorder so many years ago is quite stilted, amazed at the capabilities of this new dcevice. Though to me it sounds a bit like one of many ghosts captured by this machine.