In portuguese, that word would be "né?", or "ahn?" in a different context.
- Russian: "э?" or "а?" ("eh?" or "a?")
- Japanese: "え?" ("eh?")
This voice synth is accurate: https://translate.google.com/#fr/fr/hein%3F (click on the speaker at the bottom left of the text box).
Edit: It's pretty close to its portugese counterpart: https://translate.google.com/#pt/fr/ahn%3F