During the whole of a dull, dark, and soundless day in the autumn of the year […] (1)
This is an appropriate setting given Usher’s overly-acute senses; he can’t handle bright lights or sounds, and so the story’s setting is dull and soundless.
…. with an utter depression of soul which I can compare to no earthly sensation more properly than to the after-dream of the reveller upon opium--the bitter lapse into everyday life--the hideous dropping off of the veil. (1)
The Usher estate is made to seem as though it is its own isolated world, different and separate from normal reality.
His voice varied rapidly from a tremulous indecision (when the animal spirits seemed utterly in abeyance) to that species of energetic concision--that abrupt, weighty, unhurried, and hollow-sounding enunciation--that leaden, self- balanced and perfectly modulated guttural utterance, which may be observed in the lost drunkard, or the irreclaimable eater of opium, during the periods of his most intense excitement. (9)
This is the second time the narrator has used the simile of an opium addict to describe Usher or the mood the mansion yields. There is a sense of mad delirium expressed here.
He suffered much from a morbid acuteness of the senses; the most insipid food was alone endurable; he could wear only garments of certain texture; the odours of all flowers were oppressive; his eyes were tortured by even a faint light; and there were but peculiar sounds, and these from stringed instruments, which did not inspire him with horror. (10)
It is this same acuteness of the senses that allows Roderick to sense Madeline’s return before the narrator.
We painted and read together; or I listened, as if in a dream, to the wild improvisations of his speaking guitar. (15)
The retreat into the worlds of art and music is, for Usher, a retreat away from reality.