Answer :
The word from this excerpt could be used to argue that the narrator is unreliable is "Unnerved" suggests the narrator’s nervousness.
"The Fall of the House of Usher" is a story written by Edgar Allan Poe in 1839. The book talks about the metaphorical fall of the Usher family.The story centers on Poe's friend who was sick.
Unreliable in this context is to be not trust to deliver regarding something or not depended on regarding something or an issue.
Conclusively we an say that the narrator was nervous and when the sound left his lips, it was like a very heavy thing to say.
Learn more from
https://brainly.com/question/11357147