Which of the following conditions affects the outer ear due to pressure changes?

The correct answer is associated with the phenomenon known as an outer ear squeeze, which occurs when there are pressure changes that affect the outer ear. This condition typically arises when a diver descends or ascends rapidly without equalizing the pressure in the ear canal. As the external water pressure increases during descent, the pressure in the outer ear may not equalize, leading to a pressure differential. This can cause discomfort and, in some cases, injury to the tissues of the outer ear as they are compressed by the higher external pressure. Recognizing the importance of equalization techniques is crucial to prevent this issue and to ensure safe diving practices.

In contrast, gas embolism refers to the introduction of gas bubbles into the bloodstream, which is related to decompression sickness and affects the circulatory system rather than the outer ear. An inner ear squeeze affects the inner ear structures, often leading to more serious complications such as vertigo or hearing loss, and is a separate issue related to pressure changes in the inner ear. Face squeeze occurs when pressure changes affect the soft tissues of the face, particularly in areas where there are air-filled cavities or sinuses, and it does not pertain specifically to the outer ear.