The U.S. Marine Corps has noticed that the widespread use of silencers for all infantry weapons is a worthwhile investment. This was long suspected but no one was crazy enough to try it out on a large scale. While silencers do not make the gunfire sounds disappear there is a significant reduction of the noise levels and more combat troops have noticed the advantages. The marines recently ran a field test in which a battalion of marines had all its firearms (from rifles to heavy, 12.7mm, machine-guns) equipped with silencers. Participants and observers noted that it made an enormous difference. It was also discovered that the cost was not exorbitant (less than a million dollars per battalion). All this was part of a trend.
Since 2001 the use of "silencers" for all sorts of weapons (from pistols to assault rifles and a growing number of machine-guns) has become increasingly popular on the battlefield. Actually, calling these devices silencers is a misnomer. The sound of a gun firing is not silenced but it is significantly reduced, or suppressed, by these tube like devices that are screwed onto the front of the barrel. Thus the more common term these days is "suppressor" (of sound, recoil, and hot gasses blown back into the face of the shooter).
This suppression is useful on the battlefield as it confuses the enemy as to where the fire is coming from. This is often a matter of life or death for snipers, who sometimes use suppressors when the targets are relatively close. Machine-guns will sometimes use suppressors (which have recently become available for these weapons), not just to confuse the enemy but to make it easier to aim the fire. The suppressor reduces recoil and the hot gasses that are blown back into the face of the gunner. Both of these items make it difficult to carefully aim the machine-gun.
The pistol suppressors have been around the longest and are mainly used by special operations troops. But sometimes regular infantry will use them for raids that require that sort of thing. Pistol suppressors do make the weapon almost silent and this is essential for commandos who wish to maintain the element of surprise. But having all troops use silencers gives your side a considerable edge, especially if your troops are better trained and have better communications gear (like individual radios.) On the down side the suppressor requires regular cleaning, but the troops will tolerate that if it pays off in combat.