Which component of the inner ear contains the sensory hair cells essential for hearing?

• A. Oval window
• B. Semicircular canals
• C. Organ of Corti
• D. Vestibule

Answer: (C)

The organ of Corti in the cochlea is the hearing receptor because it contains the sensory hair cells that transduce mechanical vibrations into neural signals. When sound causes the basilar membrane to move, the stereocilia of these hair cells bend, opening ion channels and triggering neurotransmitter release to the auditory nerve fibers. This neural signal travels to the brain as the perception of sound.

The oval window is the boundary where the middle ear transfers vibrations into the inner ear, not a sensory organ. The semicircular canals detect rotational (angular) head movements and help with balance, containing hair cells in the ampullae. The vestibule houses structures that detect linear acceleration and head position. These are important for balance, not hearing.