Simlish, the pseudo-language of The Sims and various Sims spinoffs, injects a bit of extra character into these games while ingeniously avoiding the need to translate spoken words into different languages.
I get the impression that it's mostly improvised gibberish by the voice actors, but I've also heard that the musical guests are given sheets of Simlish lyrics when they re-record their songs for the games. This makes sense as it would help keep the language sounding consistent, but it makes me wonder how the translated lyrics come about. Do they have in-house people who improvise the song in Simlish, write it down, and give it to the artists to perform, or is there some automatic translation (software?) that converts English to Simlish? If the latter, wouldn't it be possible to translate it back for fun?