Final answer:
The cochlea and vestibular apparatus are situated within the petrous region of the temporal bone, part of the bony labyrinth, functioning in hearing and balance respectively.
Step-by-step explanation:
The cochlea and vestibular apparatus are structures located within the petrous region of the temporal bone, more specifically in the bony labyrinth. The cochlea is responsible for hearing, as it transduces sound waves into neural signals, while the vestibular apparatus, composed of the utricle, saccule, and three semicircular canals, is essential for balance and equilibrium. These structures send signals to the brain via the vestibulocochlear nerve, which passes through the internal auditory meatus.