Final answer:
The internal ear contains a bony and tortuous chamber system known as the labyrinth or bony labyrinth, filled with perilymph. It encompasses the cochlea and vestibule, responsible for hearing and balance.
Step-by-step explanation:
The internal ear consists of a system of bony and rather tortuous chambers called the labyrinth, or bony labyrinth, which is filled with an aqueous fluid called perilymph. It serves as a hollow structure that is the most internal part of the ear, containing the sites of transduction of auditory and vestibular information.
The cochlea and vestibule within the labyrinth are essential for audition (hearing) and equilibrium (balance), respectively, transducing sound waves into neural signals that are relayed to the brain.