During WWII our place was registered as a farm and we could buy .22 shorts which we kids used to shoot squirrels and rabbits for the table. They didn’t make much noise. I had a friend in grad school that said he shot a wild monkey in Coconut Grove with a .22 silenced with a cardboard tube.
The new barrel-break pellet rifles shoot almost as fast as a 22 short, 800+ fps, and they are cheap to shoot.