I noticed that no one ever responded to the question about recoil.
Sound has nothing to do with recoil and gas escape ahead of or behind the bullet contributes only about 10% to recoil, so a can or a muzzle brake has a limited effect. Recoil is the result of bullet motion, so most of it occurs while the bullet is in the barrel, before it even reaches the can or the brake. A brake diverts some of the gas upward or backward to counter the recoil, and a can slows and reduces the amount of gas coming out of the muzzle. Both have an effect on recoil, but not a lot. If the goal is recoil reduction, that can be achieved at a lot less cost and trouble than the hassle of buying a suppressor.
Jim