The Last Stand: Union CityEdit
The noise rating of a weapon determines the amount of attention it attracts with each shot. A weapon with a lower noise rating is less likely to be heard by distant zombies, and allows the player to quietly pick their enemies off. A weapon with a high noise rating will stir any and all zombies in the same room as the player, causing them to rush towards the player. Zombies tend to go for the survivor with the noisiest weapon, and may run past companions or the player in order to attack said survivor.
Melee weapons generally do not produce any noise, with the exception of the Chainsaw, which produces a loud noise continuously. All projectile weapons have varying noise levels; only the Thudder has a noise rating of zero.
The Suppressed weapon attachment can reduce the noise rating of a weapon, at a small cost to damage. The Spec Ops attachment reduces noise without any reduction in damage, with a boost to accuracy as a bonus.
The Last Stand: Dead ZoneEdit
Much like in The Last Stand: Union City, a weapon with a high noise rating will attract unwanted attention, enticing zombies to move towards the survivor wielding the noisy weapon. This can make it difficult for survivors to use stealth. Noise can be used to the player's advantage, however; with skill, a noisy weapon can divert hordes away from vulnerable survivors, such as the medic and scavenger. It can also be used if the player is trying to kill a large amount of zombies, such as for an infected bounty or a survivor request. Noise also determines the suppression rating of a weapon; a weapon with a greater noise rating is better at suppressing enemies than a quieter one.
Melee weapons again do not produce noise, with the exception of chainsaws, the Stars Wor™ - Plastic Laser Sword, and both Bootleg Laser Swords. The SSG-12 is the quietest of all firearms with a noise rating of 0, being based off the Thudder from The Last Stand: Union City. Bows as well produce a very small amount of noise, but are not completely quiet.