Of all the challenges in audio post-production, group dialog recording might be the most peculiar.

Here “loop groupers” are recorded speaking in tongues heard around the globe — or, in some cases, across the galaxy.

Gwendolyn Yates Whittle dealt with interstellar looping on “Avatar,” including ADR (automated dialogue replacement) sessions in the made-up Na’vi language.

“I sat down with the ADR people and we picked the lines we needed recorded, then I sent them down to Paul Frommer, who made up the language,” she says. “He sent us the lines written out as well as phonetic MP3s.”

Lines and MP3s in mind, the team assembled on a stage with a handful of professional loopers, who specialize in voice performances, and some of “the Troupe,” the performers who had worked on years of performance-capture shooting and played many of the background Na’vi characters — but don’t normally do looping.

“The stunt people (from the Troupe) helped the loopers with the language, and the loopers helped the stunt people with looping.”

While ‘Avatar’ was Whittle’s first time handling a made-up alien tongue, it was not her first pic with foreign-language ADR. “Munich” was the most complicated, but “Lions for Lambs” taught her a good lesson.

“There was Urdu and Pashai in ‘Lions,’ which was pretty intense because I didn’t know those at all,” she recalls. “When I got back to (Skywalker) Ranch to cut it, I asked a woman who spoke Urdu to come in with me to make sure I didn’t put stuff in out of context. She kept listening to this one guy and she said, ‘He’s not speaking any language. He made that all up.’ She nailed him.”