"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" (Poe 753).
Usher is supposed to be a reflection of the United States of America. At the time the story was written America was facing the pressure that would lead to the civil war which would split the nation.