Could I make a silencer for my air canon?

I’m wondering, my air canon see here is fairly noisy. That video has AA batteries, with the new projectiles I made its a bit quieter, but I was thinking, could I make a silencer? I could make an adapter from ¾” pipe to 2 inch pipe, and have some sort of flat things (maybe strips of computer case metal) inside to slow down the air like a real silencer. The question is, do you think it would work with something like this? Would it even make the noise any quieter?