David A. Angar was an individual listed on S.H.I.E.L.D.'s Gifted Index. At some point, he developed throat cancer, and underwent an experimental treatment to cure his cancer. The energy that bombarded his vocal chords destroyed the tumors, but changed his voice. Since then, his voice carried the power to put anyone that hears it, even a whisper, into a catatonic state. When S.H.I.E.L.D. took notice of this, they decided he was not much of a threat to those around him. The agents in charge of detaining him put a muzzle around his face that prevented him from talking, and imprisoned him in the secret sub-basement of the Brynmore Psychiatric Facility in Ohio. He was later broken out by Calvin Zabo with the purpose of destroying SHIELD, his muzzle removed, and allowing him to unleash his devastating vocal powers against those who tried to cross his path. Phil Coulson's SHIELD team soon arrived to contend with the Slicing Talons, and, after Cal was taken away by a vengeful Gordon, David was defeated in combat and placed into SHIELD custody.
After some time being locked up in the Raft, he was broken out and recruited into the Masters Initiative by a certain masked member of the Zemo dynasty. From there, David Angar was given the codename of Angar the Screamer, and undertook rehabilitative treatments to allow him to speak normally while controlling the intensity of his sonic screech abilities.