What do the reactions to Sir Launcelot’s “Mad Thirst” reveal about the narrator’s and Roderick’s different points of view in the passage?

While the narrator is reading Mad Trist to Usher, he thinks he hears a "cracking and ripping sound," a "screaming or grating sound," and a "distinct, hollow, metallic, and clangorous . . . reverberation." I don't think Ushe has the same reaction as the narrator.