Silencers are a greatly misunderstood component of firearms, due in large part to their portrayal in video games and actions movies.
Although silencers can greatly reduce the noise of a firearms, they do not eliminate the sound of a gunshot completely. Instead, silencers limit the noise to a hearing-safe level, keeping a firearm's burst below 140 decibels.
A pistol equipped with a silencer, for example, is slightly louder than a thunder clap - while being a tad quieter than a dish breaking.
The main benefit of silencers isn't in the element of surprise, but in helping to reduce hearing damage. Hearing loss is the most common disability claimed by veterans.
The following infographic from SilencerCo helps clarify some basic facts about firearm silencers. SilencerCo