Final answer:
Air pressure on each side of the eardrum is equalized through the Eustachian tube. It maintains ambient air pressure in the middle ear which is essential for proper hearing. The Eustachian tube is distinct from other inner ear structures like the cochlea and semicircular canals, which are involved in hearing and balance respectively.
Step-by-step explanation:
Air pressure on each side of the eardrum is equalized through the Eustachian tube. The Eustachian tube connects the middle ear to the nasopharynx, which is the upper throat and the back of the nasal cavity. It helps to ventilate the middle ear space, ensuring that pressure remains at near normal ambient air pressure, which is crucial for the proper function of the eardrum and auditory transduction mechanisms. The middle ear is connected to the inner ear, where the cochlea, a coiled tube, is part of the inner ear responsible for converting vibrations into neural signals. The semicircular canals are part of the vestibular system, involved in balance, rather than in the process of equalizing ear pressure. The Eustachian tube's role is essential for comfortable hearing and the prevention of middle ear infections that may occur due to unequal air pressure across the eardrum.