The short narrow tube that runs from the auricle to the tympanic membrane

External auditory meatus

Explanation:

The pinna leads into the external auditory meatus which is a tube that directs sound waves to the tympanic membrane. The tube is lined with hairs which trap solid particles that may enter the ear. It is also lined by wax secreting cells whose function is to secrete wax that traps dust and prevents entry of solid particles. The wax also maintains the flexibility of the eardrum.