AST Surgical Technologist Practice Exam

Which part of the inner ear is essential for hearing?

1. Cochlea

2. Semi-circular canals

3. Vestibule

4. Tympanic membrane

The correct answer is: Cochlea

The cochlea is the part of the inner ear that is essential for hearing. It is a spiral-shaped organ that converts sound vibrations into electrical signals, which are then transmitted to the brain via the auditory nerve. The cochlea contains specialized hair cells that respond to different frequencies of sound, allowing us to perceive a wide range of pitches. The fluid-filled structure of the cochlea also plays a crucial role in the mechanics of sound wave propagation and the conversion process. The semi-circular canals are primarily involved in maintaining balance and detecting rotational movements of the head, rather than in the process of hearing. The vestibule contributes to our sense of balance as well and serves as a connection between the cochlea and semi-circular canals, but it does not play a direct role in hearing. The tympanic membrane, commonly known as the eardrum, transmits sound vibrations from the outer ear to the inner ear however, it is not part of the inner ear itself, and its function is more related to sound transmission than to sound perception. Therefore, the cochlea is the key structure in the inner ear responsible for the sensation of hearing.