Which term refers to the outside structure of the ear?

The term that refers to the outside structure of the ear is indeed the pinna. The pinna, also known as the auricle, is the visible part of the ear that is located outside of the head. Its primary function is to collect sound waves and channel them into the auditory canal, which leads deeper into the ear. The unique shape of the pinna assists in localizing sounds, helping the brain determine the direction from which a sound originates.

Other terms in the question refer to different parts of the ear. The cochlea is a spiral-shaped structure within the inner ear crucial for hearing, while the auditory canal is the passage leading from the outer ear to the eardrum. The tympanic membrane, also known as the eardrum, is located deeper inside and plays a role in converting sound waves into vibrations that can be processed by the inner ear. Each of these parts is essential for hearing, but only the pinna is the external structure.