Which structure of the external ear collects sound waves?

• A. Pinna
• B. Tympanic membrane
• C. Eustachian tube
• D. Cochlea

Answer: (A)

Verified step by step guidance

1. Identify the structures listed in the problem: Pinna, Tympanic membrane, Eustachian tube, and Cochlea.
2. Understand the function of each structure: The Pinna is the visible part of the ear that collects sound waves and directs them into the ear canal.
3. Recognize that the Tympanic membrane, also known as the eardrum, vibrates in response to sound waves but does not collect them.
4. Note that the Eustachian tube helps equalize pressure in the middle ear but is not involved in collecting sound waves.
5. Acknowledge that the Cochlea is part of the inner ear responsible for converting sound vibrations into neural signals, not for collecting sound waves.