Where does Poe use punctuation or repeated words or phrases to show the mood of horror and suspense in "The Tell-Tale Heart"?

Poe uses punctuation and repetition to develop the mood of horror and to build suspense. In the first paragraph, he uses three question marks in a row. The effect is an anxious and demanding tone, which builds suspense by making the narrator unpredictable.
In the second paragraph, he uses an exclamation mark and repetition immediately. Poe writes, "Listen! Listen, and I will tell you how it happened." The exclamation mark increases the urgency and couples with the order to "Listen!" to increase the demand from the first paragraph. These devices build suspense by making the reader wonder what we are about to listen to. Throughout the story, Poe continues to use question marks and exclamation marks to build the horror.
The narrator reveals the murder he committed early on, but Poe builds the horror by slowly revealing details. With repetition and strategic punctuation, these details build the suspense. For example, Poe writes, "Slowly, little by little, I lifted the cloth, until a small, small light escaped from under it to fall upon—to fall upon that vulture eye!" By repeating "to fall upon" with an em dash, Poe slowly lifts the veil on the horrors of that night; he takes his reader to the very moments the narrator relives.
In the final paragraph, Poe's narrator illustrates his fervor with eight exclamation marks. He has committed an act of horror, and he can no longer refrain from shouting it!