Soyeong L. answered 07/04/22
Native Speaker
"여보세요" does mean "hello" in the context of a call.
If you heard it in the middle of a conversation and it sounded like a question, it would be like saying: "Hello, are you there?"
However, if it sounded angry, then I believe it was used in a "hey, listen up" sort of way.
For example, if someone were to say something you thought was out of line, then you could use it, but it would be very confrontational and would be considered rude.
Hope that helped!