The ossicles transmit sounds from the air to which structure?

• A. The vestibule
• B. The cochlea
• C. The semicircular canals
• D. The eardrum

Answer: (B)

Ossicles transfer the vibrations from the tympanic membrane into the inner ear by pushing on the oval window. This sets the fluid in the cochlea into motion, where hair cells convert the mechanical energy into electrical signals that the brain interprets as sound. The vestibule and semicircular canals are involved in balance, not hearing, and the eardrum is where sound first vibrates before the ossicles take over. So the energy ultimately reaches the cochlea.