Echo chambers were a part of the Adnerem species' anatomy which functioned like the ears found in many other species including Humans. They consisted of a hollow chamber located on top of the Adnerem's triangular head, which was similar to a tumor in appearance.
- Wanted by Cracken (First mentioned) (Picture only)
- Star Wars Adventure Journal 11 (First mentioned)
- Galaxy Guide 11: Criminal Organizations (Picture only)
- Alien Encounters