This machine pronounces, in a monotone voice, a string of numbers used by intelligence agencies for one-way shortwave radio communication with their agents in enemy countries. This machine belongs to a German collector who has a vast collection of various spy-gadgets. There were many machines of this particular model produced in East-Germany for usage within the DDR itself or other communist bloc nations, like the Soviet Union or Cuba.
In Germany (east or west) this machine was referred to as a "sprach/morse generator", which is German for "speech/morse generator". In the previous videos I've shown you I mentioned that the speed by which this generator pronounces the numbers can be changed. Hopefully this video will make it clear why sometimes there were seemingly different "German ladies" to be heard, where in fact it was the same voice but only played at a different speed/pitch.