Ultra-high resolution transmission electron microscopy of rat otoconia shows that the crystallites are 50-100 nm in diameter, have round edges and are highly ordered into laminae.

[5] The first of these layers is the otolithic membrane which uniformly distributes the force of inertia of the non-uniform otoconia mass to all stereocilia bundles.

The greater relative mass of the membrane, due to the presence of the otoconia, causes it to lag behind the macula temporarily, leading to transient displacement of the hair bundle.

Consequently, one might expect that these different stimuli would be rendered perceptually equivalent when visual feedback is absent, as occurs in the dark or when the eyes are closed.

In similar fashion, transient increases or decreases in firing rate from spontaneous levels signal the direction of linear accelerations of the head.

[1] The range of orientations of hair cells within the utricle and saccule combine to effectively gauge the linear forces acting on the head at any moment, in all three dimensions.

Ultimately, variations in hair cell polarity within the otolith organs produce patterns of vestibular nerve fiber activity that, at a population level, unambiguously encode head position and the forces that influence it.

[6] The researchers concluded that when coupled and loaded by the otolithic membrane, hair bundles of the bullfrog sacculus do not oscillate spontaneously but are poised in a dormant regime.

[6] A further study further demonstrated that the motion evoked in the hair cell bundles induced by the otolithic membrane, was found to be highly phase-locked which was consistent over large portions of the sensory epithelium.

[7] Although the pathophysiology of otolithic dysfunction is poorly understood, a disorder of otolith function, at a peripheral or central level, may be suspected when a patient describes symptoms of false sensations of linear motion or tilt or shows signs of specific derangements of ocular motor and postural, orienting and balancing responses.

When disorientation is severe the patient may describe symptoms which sound bizarre, raising doubts over the organic basis of the disease.

[8] Benign paroxysmal positional vertigo (BPPV) is the most common vestibular system disorder and occurs as a result of otoconia detaching from the otolithic membrane in the utricle and collecting in one of the semicircular canals.

When the head moves, the otoconia shift, which stimulates the cupula to send false signals to the brain, producing vertigo and triggering nystagmus.

One of these techniques is referred to as a finite element method which divides the membrane into triangles and a computer is used to determine the linear combination of the functions that represent the displacement which solves a complex system of equations.

Common parameters for similar models include, the modulus of elasticity, Poisson's ratio and the specific density of the otoconia.

[19] One final type of model that researchers have used to understand the otolithic membrane is related to the membrane-hair cell bundle interaction.