Final answer:
Yes, the primary function of the Eustachian tube is to equalize the air pressure on both sides of the tympanic membrane, which is essential for proper ear drum function.
Step-by-step explanation:
The function of the Eustachian tube is indeed to equalize air pressure on both sides of the tympanic membrane. When there is a difference in pressure between the middle ear and the atmosphere, the Eustachian tube can open to allow air to pass between the nasopharynx and the middle ear. This function is important for maintaining proper ear drum function and to avoid discomfort or potential damage to the ear structures. This is evidenced when the pressure is equilibrated through the Eustachian tube during activities such as swallowing or yawning, which causes the familiar 'popping' sensation in the ears.