The Sonic Resonator would fire a powerful beam from the middle point, as the concept art mentions energy gathering around the prongs that surround the main point.
It was going to use special crystals as ammo. These would be fed into the weapon via an internal magazine at the top of the gun. After the player would fire a certain amount of shots, it would play an animation showing the old crystal flying out of the gun and a new one being inserted by Duke.
This scrapped weapon is unique in that it made an appearance in LameDuke. However, only the pickup sprite can be found. Attempting to pick it up will make the player bump into it as if it were a solid object. It can be found in E4L1 and E4L3.
The Sonic Resonator is the only weapon that the player can not pick-up. It is also known as "sonic gun" in lameduke files. The player can not pick up it because it is too buggy, its coding remains in LameDuke files. It was a beam weapon. It must have been completely scraped, because there are no traces of it within the 0.99 beta version.
The Sonic Resonator was completely scrapped.