Starting on the outside of the skull, use a flow chart to order the following list in the correct order that sounds would pass through them before they could be heard: auricle, chochlea, external auditory meatus, incus, malleus, organ of corti, oval window, stapes, temporal love, tympanic membrane, vestibulocochlear nerve.

The order is:
Auricle (outer ear or pinna)
Auditory meatus (ear canal)
Tympanic membrane (eardrum)
The ossicles (ear bones) - malleus, then incus, then stapes
Oval window (where stapes transmits vibrations into cochlea)
Cochlea (the snail shell lines internally by specialized cells that form the organ of Corti)
Organ of corti (specialized “hair” cells that pick up vibrations from the fluid in the cochlea)
Vestibulocochlear nerve (transmits signals to brain for processing)
Temporal lobe (brain region that processes auditory information)

I’d recommend you do a quick google search as well to take a look at a diagram showing all this anatomy!

It would be the equator.