Silencers, or more accurately called "suppressors" are just that. They do not make a rifle shot silent, but rather muffled and far less intrusive to the human ear. According to OSHA, the human ear safety threshold is 140 decibels. Most common deer rifle shots are far louder and have resulted in, no doubt, generations of hearing damaged hunters. Suppressors are typically fitted to the end of the rifle barrel to simply muffle the sound as it exits the barrel and breaks the sound barrier.