David is listening to his grandson tell him a story. He is finding that he is having difficulty following what his grandson is saying. When his grandson says, "I had fun," David thinks he said "I had sun." What is David experiencing?

Presbycusis

Explanation:

Presbycusis: The term "presbycusis" is defined as the gradual process of hearing loss that tends to occurs in most of the individuals as soon as they grow older. However, hearing loss is generally a very common disorder which is connected with ageing and almost thirty to thirty-five per cent people with sixty-five years of age encounters hearing loss.

Symptoms:

1. Speech of another person's sound slurred or mumbled.

2. Difficulty in understanding a specific conversation, etc.

In the question above, David is experiencing presbycusis.