Small, wearable device that alters the voice patterns of its wearer, making the user sound like a Goa'uld or Tok'ra -- as if he or she was possessed by a symbiote. The device was used by Stargate Command personnel during training scenarios when one or more persons was playing the role of a Goa'uld spy.
Vala Mal Doran also possessed her own version of the device in the shape of a bright crystal, which was integrated into many of her wardrobe pieces. This enabled Vala to pose as the Goa'uld Qetesh on P8X-412 even after she had been freed from the symbiote's control. Her device can be deactivated by a gentle tap of the hand.
Proving Ground - The voice modulator technology comes in hand during training scenarios for potential S.G.C. candidates.
The Powers That Be - Vala uses her own version of a voice modulator to make the people continue to believe that she is their god, Qetesh.