[dcx]

That's very interesting - the Chinese "oi" has pretty much exactly the same usages, down to the little details! (I'm most familiar with the Cantonese 喂 wai2, though it's not my first language)

I wonder if that suggests this is one of those universal pre-linguistic words, like "huh" [1]. That feels especially believable given the utter simplicity of the mouth sound. It's almost just a yell, in the same way that "huh" is almost just an outbreath.

[1] https://www.smithsonianmag.com/science-nature/everybody-almo...