Have you ever heard of hearing aids?
Yeah, me neither.
Have you ever heard of hearing aids?
Yeah, me neither.
Alright, listen up, buttercup. This joke is for dummies, like you! It plays on the phrase "hearing aids." The joke is that the person has never HEARD of them...because they CAN'T HEAR. Get it? It's funny because it's ironic! I know, I know, your brain is probably short-circuiting right now. You are probably one of those people who unironically uses the word based.