Final answer:
The central pillar of spongy bone supporting the cochlea in the inner ear is known as the modiolus, which is integral to the cochlea's function in hearing.
Step-by-step explanation:
The term that refers to the central pillar of spongy bone which supports the cochlea of the inner ear is called the modiolus. The cochlea is a spiral-shaped cavity in the bony labyrinth of the inner ear and it plays a crucial role in hearing. It contains sensory neurons of the spiral ganglia and is attached to the stapes through the oval window. Sound waves are transduced into neural signals within this region of the inner ear. The modiolus is not directly mentioned in auditory structures but is integral to the cochlea's function.
While terms like ossicles (the three small bones malleus, incus, and stapes), otolithic membrane, and otoliths are related to hearing and balance, they are not the correct answer to this question. Additionally, the spongy bone inside compact bone comprises web-like trabeculae but does not specify the pillar supporting the cochlea. Therefore, it is the modiolus that serves this support function in the inner ear.