I often teased my deaf mom when I lived at home
Why would you make fun of your mom for being deaf?
Her disability put me down somehow and I wanted to make her feel like shit.
That's incredibly cruel and disrespectful. It's not okay to intentionally want to harm your mom for something she can't control.
It's fine. She can't hear me anyway.
That shows a lot of ignorance. Your mom can understand a lot of different social cues and probably understands how you feel about her. You should try to be nicer to your mom and not take out your feelings on her.