Silence in The Fall of the House of Usher is usually treated as atmosphere. The house is quiet. The corridors are hushed. The characters speak softly. The stillness feels oppressive, funereal, Gothic.
When readers talk about unreliable narrators, they usually mean one thing: perception. The narrator misjudges, misunderstands, or misinterprets events. His senses are flawed. His impressions are distorted. Reality leaks through at odd angles.
