Castiel studied him with intrigue. "Duma. I am Castiel. Do you... hear?" He signed as he spoke, just to be sure. He'd never heard of a deaf angel before, but then, he'd never met an angel that could make themselves look like a human either. Even Michael and Lucifer and Gabriel and Raphael required a vessel to appear as and interact with humans.
He did, however, recognize the name - Duma, the angel of silence, one of those who had followed Lucifer, and had been cast out with him. Castiel was too young to know him from more than stories passed down by his superiors in Heaven - one of those who'd rebelled, treasonous to heaven. Once, Cas might have turned away, but who would he be to pass judgement now? He had plenty of sins staining his own conscience without casting stones at others.
Anyway, Castiel wasn't sure who this was, but he couldn't be the same one Cas had heard of. Either that, or perhaps his senses were more distorted than he'd thought. He'd thought he hadn't had a hallucination in some time... but of course, how would he know? Castiel moved to sit at the other end of the bench, his posture loose and open. His intense stare never left the other angel. "You feel different," he said, a little awed. "You can tell, can't you?"