The Voice Filter is an armor enhancement that uses special filters built into the user's helmet in order to disguise their voice, either to protect their identity or in order to trick enemies into lowering their guard.
- Tex: This armor enhancement was used by Tex when she was first introduced in A Shadow of His Former Self to give herself a male voice. This, combined with the fact that Tex is typically a male name, made everyone believe she was a man. However, her disguise was foiled when Sarge broke the filter with the butt of his shotgun upon knocking Tex out in Down, but not Out. Presumably, this damage was never repaired and her new body never contained it, as she is never seen using the enhancement after that.
- South Dakota: In The Twins, South uses the enhancement to lure Scully into a location where she could quietly take him out by imitating the voice of his colleague, Murphy.
- All characters who wear armour have some degree of filtering while wearing their helmets. Whether this armour enhancement causes it or it is caused by regular auditory helmet filters is unknown.
- Only female Freelancer personnel have used this enhancement specifically to disguise their voice, in both cases changing their voice to a male one. It is unknown whether only female personnel have this enhancement, or it is standard equipment.
- Locus has a heavier filter on his helmet than the rest of the cast, strongly suggesting he is a user of this enhancement. However, this remains unconfirmed.
- It was widely speculated that the Insurrectionist Leader, while posing as C.T., was actually C.T. using a voice filter to disguise herself as a man, based on Tex's and South's use of the enhancement. This theory was eventually disproved in Season 10.