A device used for communication was called a bubble machine. This machine was the primary method of communication for Aanxi Raanxi Laanxi.
The book Monsters and Aliens from George Lucas, which came out in 1993, included a reference to the bubble machine. Leland Chee, an employee of Lucasfilm who is responsible for the Holocron continuity database, has stated that the information within the book is considered non-canonical.