Final answer:
The otolithic membrane is the gelatinous material that the hair cells of the maculae contact. It contains calcium carbonate crystals and moves independently from the macula to convey head position to the brain.
Step-by-step explanation:
The hair cells of the maculae are in contact with a sheet of weighted gelatinous material called the otolithic membrane.
The otolithic membrane is a viscous gel found in the utricle and saccule of the inner ear and contains calcium carbonate crystals. These crystals, known as otoliths, render the otolithic membrane top-heavy, causing it to move independently from the macula in response to head movements. This movement bends the stereocilia of the hair cells, leading to depolarization or hyperpolarization of these cells, which allows the brain to interpret the position of the head based on this pattern of hair-cell activity.