I must be skimming too much. They say "huh" is universal but point out Japan (and apparently Korean) use "eh". "eh" != "huh", not even close nor is its usage. Maybe these are are different but you can use "eh" to acknowledge you heard. With a question inflection to point out you didn't hear.
Huh is not used in spanish at all. Maybe in the more english-influenced caribbean regions but in the southern cone we don't say "huh" at all, rather "eh?".
I find it to be automatic for a lot of people. I know several people that go "mh?" (in english) or "hein?" (in french) when they perfectly understood what you said. It's just a reflex, maybe to give themselves a bit more time to think. It's a bit annoying, I often just wait a second and they start answering
As a teenager I did that too, I always replied (the equivalent in my langague of) "what?" to whatever was said. Just a reflex. Then my aunt pointed it out to me, and I was able to stop doing that. Good thing.
Ah that reminds me of when I was in school, and there was a girl who started every answer with "Okay!...".
The teacher would ask, "What's the capital of X?", and she'd respond confidently (and correctly), "Okay! The capital of X is Y."
Not sure if it was conscious on her part or not. I'm sure it came from the spotlight, since she was otherwise "normal" (not that there necessarily is such a thing).
> Everywhere this word appears to be a simple syllable with a low-front central vowel, glottal onset consonant if any, and questioning intonation.
My wife's parents have a similar thing in English as an aside. `Huh` indicates that they've heard something novel, `huh?` indicates that they didn't hear you.
