Final answer:
As a person descends from a high altitude to a lower altitude, the external air pressure on the tympanic membrane increases. This pressure difference can temporarily affect the eardrum's ability to vibrate and thus impact hearing until the pressure equalizes.
Step-by-step explanation:
As a person moves from a high altitude to a lower one, air pressure on the outside of the tympanic membrane increases. This change in pressure can affect hearing because the tympanic membrane, or eardrum, reacts to sound pressure variations. If the external pressure is greatly different from the pressure in the middle ear, the eardrum can have difficulty vibrating normally, which affects how sound is transmitted to the inner ear and can lead to temporary hearing problems, or the sensation of 'popped' ears.
The tympanic membrane works as part of a complex system that converts sound waves into nerve impulses. When sound waves strike the eardrum, it vibrates, and these vibrations are transferred across the tiny bones of the middle ear (the malleus, incus, and stapes) to the oval window. This action then causes pressure waves in the cochlea of the inner ear, which are eventually processed as sound. However, if there's an imbalance in pressure, such as when moving from high to low altitude, the efficiency of this process can be impaired until the pressure normalizes again.