Final answer:
This excerpt from "The Raven" uses alliteration and repetition to create a musical quality and enhance the ambiance and suspense of the poem.
Step-by-step explanation:
This excerpt from "The Raven" by Edgar Allan Poe uses the sound devices of alliteration and repetition. Alliteration refers to the repetition of consonant sounds at the beginning of words in a sentence or phrase. In this excerpt, the repeated 's' sound in 'silken sad uncertain' creates a musical quality. Repetition, on the other hand, involves the repeating of words or phrases for emphasis or to create a certain rhythm. Here, the repetition of 'curtain' at the end of the line emphasizes the movement of the curtains and adds to the overall ambiance and suspense of the poem.
Learn more about sound devices in poetry