Final answer:
The external acoustic meatus is synonymously referred to as the auditory canal, part of the ear's anatomy involved in directing sound waves to the eardrum.
Step-by-step explanation:
The external acoustic meatus is also known as the auditory canal. This tubular structure is an essential part of the ear's anatomy and plays a significant role in the process of hearing. The external acoustic meatus is the passage through which sound waves travel into the ear, ultimately hitting the tympanic membrane, or eardrum, causing it to vibrate. These vibrating waves are then transmitted through the middle ear's ossicles (malleus, incus, and stapes) to the inner ear, where they are further processed and sent to the brain as neural signals. The auditory canal is visibly distinct from the other options listed, such as the pharyngotympanic tube (also known as the Eustachian tube), which connects the middle ear to the pharynx and helps equalize pressure, and the tympanic cavity, which houses the ossicles.