Cochlea is concerned with the sensation of hearing. It is a coiled structure that looks like a snail’s shell. It is a fluid filled structure present in the inner ear (of the membranous labyrinth) and it contains the sound detecting “organ of corti (spiral organ).” Organ of corti is the auditory receptor that lies on the basilar membrane, and extends throughout cochlear duct.
The organ of corti is made up of sensory cells called hair cells. These hair cells are in contact with the fibres of cochlear nerve (a part of 8th cranial nerve). More vibrations cause (sound waves at higher frequency) more hair cells fire in that region.
Thus, the blanks can be filled with cochlear; 8th cranial nerve.