Answer:
Eustachian tube
Explanation:
Eustachian tube is the auditory tube, that connects middle ear with nasopharynx. The main role of the Eustachian tube is to regulate and maintain the pressure in the ear (it equalizes the pressure between the middle ear and the atmosphere). The tube is usually closed, but it opens when we swallow and chew. It also opens with positive pressure.
Blockage of the Eustachian tube can lead to discomfort or even hearing problems.
