I'm not sure what you are trying to get at with your post, but subsonic bullets are not noiseless either. When I suppressed my 45 acp Enfield and shot 200 grain swc at 1050 fps, they made a humming noise on the way to the target. I thought it was transonic noise so I lowered the powder charge to get 900 fps and got the same noise. In neither case was it a sonic boom I was hearing, but merely the sound of an object passing through the air.
Silencers (suppressors, mufflers, moderators) suppress muzzle noise. Silencer as it is used by most people is a noun, not a verb. It is also the legal term used by the feds.
Last edited by RAnb; March 22, 2012 at 12:55 PM.