definition
(with falling pitch) used to express amusement or subtle surprise.
example
Huh! I'm sure I locked it when I left.
definition
Used to express doubt or confusion.
example
Huh? Where did they go?
definition
(with rising pitch) Used to reinforce a question.
example
Where were you last night? Huh?
definition
(with falling pitch) Used either to belittle the issuer of a statement/question, or sarcastically to indicate utter agreement, and that the statement being responded to is an extreme understatement. The intonation is changed to distinguish between the two meanings - implied dullness for belittlement, and feigned surprise for utter agreement.
example
(agreement) A: "Murder is bad." B: "Huh!"
definition
(with rising pitch) Used to indicate that one did not hear what was said.
example
Huh? Could you speak up?
definition
(with falling pitch) Used to create a tag question.
example
It's getting kind of late, huh?