edwdickinson wrote:
"Silencer" is a misnomer, it is actually a suppressor. A weapon with a suppressor can be heard, but at a greatly reduced decibel level. In a crowd where there is noise, the sound will be close to impossible to hear except to those he may be very close to the shooter. In a silent room, the shoot will still be heard.
This is partially true. "Silencer" is a colloquial term for what's more accurately called a "suppressor".
One of the primary purposes of a suppressor is to protect the hearing of the person using the firearm and any other people nearby, such as at a firing range.
Suppressors only reduce the noise of a gun to a limited extent. In most cases, it's nothing close to what's depicted by Hollywood.
A suppressor on a small caliber gun like a .22 will have quite a bit of effect. But on larger caliber they are far less effective. One example with a .22 showed a reduction from 157db to 116db.
For example, one I just looked up reduces 5.56/.226 rifle noise levels by 32 to 34db, down to around 130db which is the "pain threshold" for most people. A jet airplane is commonly around 140db and noise at or above that level is considered potentially harmful. A jackhammer or car horn at 1 meter is about 120db. A chainsaw, around 110db. A helicopter, about 105db.
A .45 pistol, two of which the shooter in Virginia Beach used and at least one of which was reported to be suppressed, is a fairly large and loud caliber. I couldn't find a specific example for comparison, but see several suppressors for .45 claiming to reduce loudness to around 130db. That sounds reasonable, since a 9mm pistol is similar, but slightly smaller caliber... typically 162db unsuppressed.... 126db suppressed.
Another legitimate purpose of a suppressor might be a rancher trying to clear out a gopher problem, hoping reduced noise from their gun won't send all the critters hiding after the first shot.
There is nothing "new" about suppressors, either. They were first developed in 1909. Federal regulations have required special licensing for ownership of a suppressor in the U.S. since 1934. It's unknown if the Virginia Beach shooter had such a license, although at least three of his guns appeared to be legal purchases.