Why Does My 3-Year-Old Always Say 'Huh?' and How to Stop It?

My 3 year old almost always says “huh?” After any time someone tells him something.. for example I’ll tell him to pick up his toys, so he responds with “huh?” Or “let’s go to your room” or “stop jumping on the couch” like he knows exactly what I’m saying but will still say “huh??” Even now I ust as I’m typing this I told him to stop slamming the door & he says “huh?” It’s more annoying than anything else really because I’m tired of having to repeat myself. Has anyone else had a kid that did this? Any idea on how to get him out of the habit?