"The former Minister of Communications and Informatics of the Republic of Lithuania has written that the purpose of the voice messages is to confirm that operators at receiving stations are alert."
When I was a kid, my uncle was a chief petty officer in a Navy submarine. The coolest thing he ever did was bring me a world band radio and taught me how to find these things. For years, Sunday nights consisted of Dr. Demento, BBC World Service, the Polish English Language Review (yes, it exists, and it's awesome) and then late night numbers hunting. Later on I was REALLY INTO Electronic Voice Phenomenon, and I've kinda grown out of that, but Numbers Stations naturally lead into that sort of thing.
I always figured it was a way for folks to infer which cities were still around after the nukes.
No buzzing coming out of Moscow....let's try Leningrad.