Conversation so far:
where is the eustachian tube located in the ear
The Eustachian tube extends from the anterior wall of the middle ear to the lateral wall of the nasopharynx, approximately at the level of the inferior nasal concha.
what does the eustachian tube do
The primary function of the Eustachian tube is to ventilate the middle ear space, ensuring that its pressure remains at near normal environmental air pressure.

Question: what other functions are there
Self-contained rewrite: what other functions are there for the eustachian tube besides ventilating the middle ear space