Angergasm
Pained, orgasm-like sounds, stemming from a bout of anger.
It's difficult to give an example of something that's sound-based, but I'd have to liken it to someone being forcibly anal raped, only they're just very unhappy about something.

"UGH!" "OH GOD!" "ARGH!" "FUUUUUCK!" and "FUCK ME!!" are all possible examples of an angergasm.