Explanation:

- Cochlear nerve: Transmits auditory information from the cochlea to the brain. It has no role in pressure equalization.

- Malleus: A small bone in the middle ear that helps transmit sound vibrations from the eardrum to the incus. It doesn't equalize pressure.

- Eustachian tube: Connects the middle ear to the back of the throat. It helps equalize the air pressure on either side of the eardrum by allowing air to flow in and out of the middle ear. It opens during activities like swallowing and yawning.

- Incus: Another small bone in the middle ear that transmits vibrations from the malleus to the stapes. It doesn't affect pressure equalization.