I used to have a friend who spoke some of a language called the “tongue of whales.” I can’t remember exactly what it sounded like, but I remember it being very foreign, not like anything I had ever heard. She said she learned it from her grandma (who apparently spoke it fluently), and also said it was an ancient language originating from southern Germany (presumably around the Danube, not spoken today.
It is definitely called tongue of whales, or language of whales, but after looking it up I can’t find anything.
Is there any ancient language originating in southern Germany, rheatia, noricum, etc, that has survived today, and or is referred to as “the tongue/language of whales”
It is likely that what is being said was "Wales" -- not "Whales". Welsh is of course a language, still spoken, but it isn't spoken in central Europe. . .
. . .but . . .
the term "Wales" has the same root as the people known to the Romans as the Volcae, this is the etymology of placenames like "Wallonia" and "Wallachia", and ethnic groups like the Vlachs (which is an exonym -- what others called them, more than what they called themselves). The original term in proto-Germanic seems to have been something like "Walhaz" . . .
So, the Vlachs were originally from the the region you specify, near the Danube. They spoke a romance language, called "Aromanian", a sound which is unfamiliar to most; that's the best guess I have for a plausible "tongue of Wales" that might have been spoken in central Europe. There aren't many Vlachs speaking Aromanian left, but there are some. How someone would have come to call it "the tongue of Wales" -- that sounds almost like they'd heard it described that way by a linguist
Thanks to the Internet, you're only a Google search away from examples of people speaking Aromanian-- take a listen and see, might be what your friend was speaking, or might demonstrate how far wrong I am.
NB-- their given and family name could also give a clue . . .
See:
Dvoichenko-Markov, Demetrius. “THE VLACHS : THE LATIN SPEAKING POPULATION OF EASTERN EUROPE.” Byzantion, vol. 54, no. 2, 1984, pp. 508–526.
Winnifrith, Tom. “A.J.B. Wace and M.S. Thompson, Nomads of the Balkans — The Vlachs.” British School at Athens Studies, vol. 17, 2009, pp. 67–75.
It's possible that r/etymology will have an answer as well.