In “The Tell-Take Heart,” the narrator is tormented and ultimately undone by the sound of an old man’s beating heart. He lives with and claims to “love” the old man; nonetheless, he is haunted by what he perceives as the old man’s “vulture eye.” In order to rid this eye from his life, the narrator resolves to kill the old man.

Therefore, he painstakingly plots to murder the old man in his sleep. Over a course of seven nights, after midnight he stealthily checks on the old man to see if the evil eye is open; each time, it is closed. On the eighth night, however, the old man wakes up and opens his eyes; spying the evil eye staring back at him, the enraged narrator also hears

a quick, low, soft sound, like the sound of a clock heard through a wall. It was the beating of the old man’s heart.

This quote describing the old man’s beating heart has several effects. First, the “quick” beating illustrates the old man’s fear, catalyzes the narrator’s rapid jump to smother the old man, and increases tension for the reader. Second, the adjectives “low” and “soft” underscore the faint yet ominous presence of the beating heart. Third, the simile comparing the heartbeat to the ticking of a “clock heard through the wall” emphasizes the muffled quality of the noise, much like the old man being smothered under his bedcovers. Most importantly, “through the wall” foreshadows the narrator’s hallucinatory hearing of the beating heart through floorboards at the end of the story.

In the final moments before he attacks the old man, the narrator becomes even more more enraged as he hears the sound's increase in volume. He describes the heart as beating “so loudly that I was sure someone must hear.” This description also foreshadows the scene at the end of the story. While chatting with policemen, narrator again hears

a quick, low, soft sound, like the sound of a clock heard through a wall, a sound I knew well. Louder it became, and louder.

This description repeats the earlier quote and simile comparing the heartbeat to an incessantly ticking clock. The sound grows so loud—probably in the paranoid murderer’s imagination only—that he cannot believe that others cannot perceive it: “Was it possible that they could not hear??” The repetition of this quote describing the beating heart links the narrator’s crazed motivation for committing murder to his hysterical impetus for confessing murder.