Having lived in New Zealand for a while.... I've owned suppressed .22s and a suppressed .308Win. (sold the suppressors and the .308 before returning to Canada) If you fire a .22 subsonic LR round out of a suppressed .22 (whether it's screwed on or slide-on suppressor) you hear a small pop from the shot, but my 10-22 made more noise cycling the bolt. Put a polymer bolt stop in the receiver, and most of the noise is from the bolt closing. .22 shorts out of a suppressed rifle, you can shoot indoors without hearing protection - the loudest noise is from the bullet hitting the target.
.22 shorts out of a log barrelled "free rifle" with a big heavy barrel, and you hear a "ping" when the firing pin spring releases and a little 'pop' from the shot.
Centrefire rifles with suppressors (yes, you can buy a fully suppressed centrefire hunting rifle in gunshops in New Zealand, and you can then hunt without wrecking your hearing and without needing hearing protection.), you get the supersonic crack of the bullet going down range, and a loud, high-pitched wheeze as the gases escape the suppressor.
At least - that's my experience. Shooting on a 1000 metre range beside a guy using a 6mm suppressed rifle was certainly different "Crack-wheeze" then the echo from the supersonic wave bouncing back from the target...