German sounds like a man being choked to death, French sounds like a cat fight, while Spanish sounds like molasses gurgling gently out of a jug, Cantonese - well, think of a man trying to vocalize Bach who doesn't like Bach very much to start with.
That's Heinlein writing in the voice of his character Podkayne in the novel Podkayne of Mars.
Now and then I think about how one might go about creating a course in recognizing languages. What does a language sound like to a person who understands none of it?
I hadn't thought of characterizing languages in quite Poddy's way. But it might provide a way to get students going. Maybe on the first day of class play snippets of each of several languages and ask the students to come up with metaphors to describe them.