The angel didn't hear the calling, but he did hear the bang, which was loud enough to make him nearly - nearly, mind - knock over the cup of tea.

Rising from his position by the window, one knee cracking, Aziraphale went to the door, through which a muffled but most decidedly pissed off voice could be heard. "Ellie, my dear?" he called, unlocking and cracking open the door to peer at the annoyed succubus.

"Why, what on earth is the matter? Is-is Crowley hurt? Did something happen? Is he all right?" The angel opened the door wider, looking past her worriedly. "Ellie, what is it?"