I bullied a kid with hearing problems
Why would you want to buuly him?
I just felt like bruising his ego.
It is cruel to bully others, especially others with disabilities. If you still know this person, you should apologize for your behavior.  And for now, you should think about why you feel the need to behave in such a way in the first place.
I only wanted to piss him off.
That is hardly a valid reason for wanting to antagonize others.  You didn't gain anything by threatening this kid, and you risked getting into a lot of trouble to do so.  If you feel like doing this again, I think you should talk to someone about what is bothering you.