What is an assonance in The Tell-Tale Heart?

In the short story "The Tell-Tale Heart" by Edgar Allan Poe, there are several examples of assonance, which is the repetition of vowel sounds in a series of nearby words. Some notable instances of assonance in the story include:

1. "And the sound increased -- and lo! the doubling of the beat." (Repetition of the "o" sound)

2. "I thought I heard a groan, a low stifled groan." (Repetition of the "o" sound)

3. "What else could I do? The old man was already dead. I could do nothing more than listen to that horrible death rattle." (Repetition of the "e" sound)

4. "I felt the icy fingers of the old man's hand." (Repetition of the "i" sound)

These examples of assonance contribute to the overall atmosphere and mood of the story, creating a sense of tension, suspense, and unease.