What is the term for the opening of the outer ear that leads to the auditory canal?

The term that refers to the opening of the outer ear leading to the auditory canal is indeed the pinna. The pinna is the visible part of the ear that collects sound waves and directs them into the auditory canal, which helps in the process of hearing. It plays a crucial role in sound localization and amplifying sound waves that travel toward the inner parts of the ear for processing.

The auditory canal, mentioned in the choices, is actually the passageway that sound travels through after leaving the pinna, while the Eustachian tube is a structure that connects the middle ear to the throat, assisting in pressure equalization. The tympanic membrane, commonly known as the eardrum, is the membrane that vibrates in response to sound waves; it is located at the end of the auditory canal and does not refer to the opening of the outer ear itself. Hence, the pinna is correctly identified as the term for the opening of the outer ear.