- French: "Hein?" which is a nasalized sound without an English counterpart. Pronounce "Haaaaa" then let some air go through your nose by raising your uvula/lowering the back of your tongue a bit.

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