Suppressors on .22 rifles for small game hunting are game changers. My Remington 541-S with its 24" barrel is very quiet with standard velocity target ammo, but the same ammo out of my suppressed CZ 455 American with a 24" barrel is unnoticeable by game past 10 yards, really. A few years ago I had a pair of squirrels come up over the edge of a ridge overlooking a creek bottom as they frolicked and foraged. When they stopped on a log about 30 yards out, I took the furthest one with a head shot. The second squirrel was spooked by the THWOK! of the bullet hitting his friend's noggin and came running at me. It stopped behind a tree and I worked the bolt slowly to reload. When it came out from cover it had moved a bit to the left and started down a log that was about 10' away. I was frozen, and then the squirrel stopped, seeing me. It was a Mexican standoff for several seconds, and then I started to slowly move the gun over... and he was off like he was shot out of a cannon! I cannot tell you how many times I've been about 50 yards out from grove of oak and hickory trees, and been able to pick off squirrel after squirrel with either a suppressed .22 rifle or one of my Daystate Pulsars with air rifle suppressors (moderators) because the squirrels don't know they're being shot at.
Another time I was squirrel hunting overlooking another creek bottom when I saw a flash of movement about 80 yards away along the edge of the creek. It was a black and white cat. I watched it through the scope until it got to within 50 yards. I didn't see a collar on it, but I don't shoot cats. I did take a shot into a log a few feet from the cat. At the bullet's impact, it jumped like it was pouncing, and then it's head was quickly twitching back and forth trying to see what made the noise. I quietly cycled the bolt and put another bullet into the log a few feet further. The cat pounced on the log, again looking for the source of the noise. After watching it for about 30 seconds as it went under and over the log trying to find the noise maker, I spoke up in a normal volume and said, "Hey, cat!" Like the squirrel, it took off like a rocket and is probably still running. I talked about seeing a cat in this area (it was a small GMA in northern Arkansas) a few days later to one of the state biologists, and he told me I should have shot it as they have a severe feral cat problem. I would have to be VERY convinced that a cat was feral before shooting it... would hate to shoot someone's pet.
Point is, even a cat couldn't figure out that it was a bullet, since it couldn't hear the report of the rifle from about 50 yards away. They are THAT quiet.