A voice disguiser, also called a voice scrambler or voxscrambler, was a piece of technology designed to alter a person's normal voice, making it difficult or impossible to determine who was speaking.
Certain types of armor, such as the suit worn by the bounty hunter Mist during the initial period of the New Republic, incorporated voice disguisers directly into their helmets.
In 25 ABY, when New Republic Senator Viqi Shesh had a secret meeting in Kuat City with Reck Desh, a collaborator of the Yuuzhan Vong, she utilized a high-end voice disguiser to conceal who she was.
The Yuuzhan Vong possessed a unique biological technology that allowed for voice alteration. However, unlike typical devices that simply made the original voice unrecognizable, the Yuuzhan Vong technology could generate an entirely new voice for the user.