The first known instance of the Doom Siren's use occurred during the early years of the Horus Heresy in the early 31st Millennium, when Space Marines of the Emperor's Children Legion began having their armour modified to carry Sonic Weapons. The first Doom Sirens were more than likely built by or for Emperor's Children Astartes who wanted to emulate the biological sonic abilities gifted to several of their commanding officers by the corrupted Apothecary Fabius Bile. Doom Sirens are also used by Chaos Sonic Dreadnoughts, and are built into the walker's face plate. These infernal devices are also used by Slaanesh Subjugator Daemon Engines during close combat.