Pakaderm Onomatopœia

aao....ooooooooooo...i think you should see cats having sex...you might get a feel for the sound of women make during intercourse.

I am sorta writing a fan-made comic adaptation to the Animorphs book series. I've gotten to the panel where Rachel morphs into an elephant and is supposed to trumpet. Now translating that sound to a spelling of the noise is tough. I'd say the japanese version sounds like the natural closest. "Pa-oo" is instant more than "urr" which to me sounds like just a misspelled "err". I came up with a sound like "Errooh!" or "Urra-ooh" as either spelling is as close I could get. How's that?

Anybody got anything closer?