A person experiences a sudden, muffled hearing sensation in one ear after cleaning it with a cotton swab. An examination reveals that a piece of the cotton has become lodged deep inside the tube that connects the visible part of the ear to the eardrum, completely obstructing it. What is the most direct cause of this person's hearing difficulty?

An individual develops a complete blockage in their ear canal due to excessive earwax. Which of the following describes the most direct impact this would have on their hearing?