Hmmm...If I think about purring to her, she giggles and is amazed I can do that. I sound just LIKE a kitty cat? It's some kind of trill. It feels like it's behind the teeth. I may be wrong and it's still a uvular trill, the same as a Wookiee growl. It's softer, though.

...It could be voiced/nonvoiced. *listen to that sound* It kinda sounds like that. What an extrapolation! I can do a uvular trill from knowing French r, although I don't know if they ever trill their r. Wookiee growl=voiced and cat purr is nonvoiced?