In 'The Tell-Tale Heart', what sound does the narrator imagine he hears after the murder?

After the murder in “The Tell-Tale Heart,” the narrator imagines hearing the old man’s heartbeat beneath the floorboards.

The narrator has killed the old man, dismembered the body, and hidden it under the boards. When police officers arrive after a neighbor reports a scream, the narrator confidently invites them inside and places their chairs directly above the concealed remains. At first, the narrator believes the crime has been perfectly hidden.

Then a faint ringing begins in the narrator’s ears. The sound seems to grow louder and faster, becoming an unbearable beating that the narrator identifies as the dead man’s heart. The officers appear not to hear it, which strongly suggests that the sound is psychological rather than supernatural. Overwhelmed by guilt and panic, the narrator confesses and demands that the floorboards be torn up.

The story leaves room for alternative interpretations. Some readers connect the sound with deathwatch beetles, insects traditionally associated with death, while others see it as the narrator’s own heartbeat or an auditory hallucination. Even so, the narrator explicitly imagines it as the old man’s beating heart.