Which structure is part of the outer ear?

• A. External auditory canal
• B. Tympanic membrane
• C. Ossicles
• D. Pinna (Auricle)

Answer: (D)

Outer-ear anatomy refers to structures external to the tympanic membrane that collect and funnel sound into the ear. The Pinna (Auricle) is the visible, external part of the ear; it catches sound and helps direct it into the ear canal, while also contributing to sound localization with its shape and folds. The tympanic membrane marks the boundary with the middle ear, so it belongs to the middle-ear region rather than the outer ear. The ossicles are the small bones housed in the middle ear that transmit vibrations from the eardrum to the inner ear. The external auditory canal is part of the outer ear as a passage that carries sound inward, but the most representative outer-ear structure among these options is the pinna, the outward, visible part of the ear.