Some good posts on here. Just wanted to add alittle knowledge for those who might not be familiar with them.
Hiram Maxim developed the "silencer " to muffle the sound of internal combustion engines, and at the same time developed the firearm suppressor.
Without shooting a sub sonic load, they are by no means "Hollywood" quiet. What they do , with standard ammo, is reduce the decibles at the muzzle. Most ear plugs are good to reduce heard noise @ 32 decibles. A decent suppressor will take @35 decibles off at the muzzle.
The super sonic "crack" is still heard, but down range. And you can not tell what direction the shot came from.