Interestingly, prior to the reading by the narrator of the Mad Trist of Sir Launcelot Canning, Roderick Usher expresses to his friend that
He was echained by certain superstitious impressions in regard to the dwelling which he tenated....an influence which some peculiarities in the mere form and substance of his family mansion, had, by dint of long sufferance, he said, obtained over his spirit--an effect which the physique of the gray walls and turrets, and of the dim tarn...brought about upon the morale of his existence.
This gothic influence of the mansion upon the soul of Roderick is later felt in the echoings of the narrative of the Mad Trist outside with the storm and within by the mansion as the narrative is read to Roderick. In a technique that Poe termed arabesque, his gothic tale, "The Fall of the House of Usher" twists and turns its horror until there is the final crescendo of terror.
Thus, as the narrator reads of Ethelred's attempts to enter the hermit's dwelling with blows of his gauntleted hand that makes cracking and tearing sounds in the hollow wood, there is an echoing of these very sounds within the mansion. And, as the narrative continues and Ethelred strikes a dragon, which gives up "his pesty breath, with a shriek so horrid and harsh...and piercing," there is, again, within the house a "harsh, protracted, and most unusual screaming or grating sound."
Finally, as the narrator reads about Ethelred's removal of the body of the dragon and taking down of a shield from a wall that falls "upon the silver floor, with a mighty great and terrible ringing sound," there is yet an echoing of this sound "distinct, hollow metallic, and clangorous, yet apparently muffled reverberation." With this final imitation, Roderick shudders and murmurs as if unconscious of his friend's presence,
'Not hear it?--yes, I hear it, and have heard it....Madman! I tell you that she now stands without the door!'
Outside nature is in accord with the fury of emotions and phenomena, providing a "rushing gust which opens the huge antique panels," revealing Madeline in her shroud, bloody and evidencing some bitter struggle. Indeed, Roderick's presentiment about his sister and the mansion are true. So closely are all three that after the climactic tale ironically named the Mad Trist, they all "fall asunder" together.