In 155, explorers out of Mechantus trekked into the Hive Region. In ancient Auhtai ruins they found devices and information on the development of sonic weapons. Dating from the middle of the Horgon Era, these devices were very advanced for the time, and for a time still in working order; Gimrune engineers destroyed the first batch in reverse engineering.
Today, Engineen's workshops are the largest makers of what the Auhtai called Päiki-Synhö; weapons using sonic energy as their primary mode of attack. The Ba'lith Empire, close to the Hive Region, near the bug parts needed to make such weapons, is the second largest producer. Balith's most well-known Päiki-Synhö is the Knell Cannon. The largest devices to-date made with this technology are the Sonic Horns lining Ba'lith's southern border; facing the ever-present threat of the Hive Swarms.
Päiki-Synhö weapons require carapaces and other parts of certain beetles and bugs found only in the Hive Region.