They aren't whole languages, just a bunch of random sounds. But, for instance Huttese all has a similar "sound" to it, it's not an actual language they way Tolkien did. It's just sound designer Ben Burtt playing around. I don't know a whole lot about the sounds of Star Wars, but I do know that some of the "languages" are actually based off human languages, for instance I believe it is the character of Nien Numb the co-pilot to Lando in ROTJ, Ben Burtt had some 90-year-old Indian woman come in and speak some obscure dialect because it sounded "alien". I'm probably misremembering the details, but that is generally how it was done. It's not like Klingon or Elvish.