Which three phrases in this excerpt from edgar allan poe's "the cask of amontillado" contribute to its gruesome atmosphere?
i had scarcely laid the first tier of the masonry when i discovered that the intoxication of fortunato had in a great measure worn off. the earliest indication i had of this was a low moaning cry from the depth of the recess. it was not the cry of a drunken man. there was then a long and obstinate silence. i laid the second tier, and the third, and the fourth; and then i heard the furious vibrations of the chain. the noise lasted for several minutes, during which, that i might hearken to it with the more satisfaction, i ceased my labours and sat down upon the bones. when at last the clanking subsided, i resumed the trowel, and finished without interruption the fifth, the sixth, and the seventh tier. the wall was now nearly upon a level with my breast. i again paused, and holding the flambeaux over the mason-work, threw a few feeble rays upon the figure within.

a succession of loud and shrill screams, bursting suddenly from the throat of the chained form, seemed to thrust me violently back. for a brief moment i hesitated, i trembled. unsheathing my rapier, i began to grope with it about the recess; but the thought of an instant reassured me. i placed my hand upon the solid fabric of the catacombs, and felt satisfied. i reapproached the wall; i replied to the yells of him who clamoured. i re-echoed, i aided, i surpassed them in volume and in strength. i did this, and the clamourer grew still.