Although large vestibular aqueducts are a congenital condition, hearing loss may not be present from birth. Age of diagnosis ranges from infancy to adulthood, and symptoms include fluctuating and sometimes progressive sensorineural hearing loss and disequilibrium.

The vestibular aqueduct acts as a canal between the inner ear and the cranial cavity. Running through it is a tube called the endolymphatic duct, which normally carries a fluid called endolymph from the inner ear to the endolymphatic sac in the cranial cavity. When the endolymphatic duct and sac are larger than normal, as is the case in large vestibular aqueduct syndrome, endolymph is allowed to travel back from the endolymphatic sac into the inner ear. This often results fluctuations in hearing levels. Enlarged vestibular aqueducts often occur with other inner ear development problems, such as cochlear deformities. Enlarged vestibular aqueducts are part of the classic Mondini deformity. Enlarged vestibular aqueducts with enlarged endolymphatic sacs occur in Pendred syndrome which is caused by a defect on chromosome 7q31.. Enlarged vestibular aqueducts can also occur in Branchio-oto-renal syndrome, CHARGE syndrome and Renal Tubular Acidosis.

Enlarged vestibular aqueducts can be bilateral or unilateral.

Hearing loss caused by large vestibular aqueduct syndrome is not inevitable, although people with the syndrome are at a much higher risk of developing hearing loss than the general population. Hearing loss is very likely.

Mondini dysplasia, also known as Mondini malformation and Mondini defect, is an abnormality of the inner ear that is associated with sensorineural hearing loss.

This deformity was first described in 1791 by Mondini after examining the inner ear of a deaf boy. The Mondini dysplasia describes a cochlea with incomplete partitioning and a reduced number of turns, an enlarged vestibular aqueduct and a dilated vestibule. A normal cochlea has two and a half turns, a cochlea with Mondini dysplasia has one and a half turns; the basal turns being normally formed with a dilated or cystic apical turn to the cochlear. The hearing loss can deteriorate over time either gradually or in a step-wise fashion, or may be profound from birth.

Hearing loss associated with Mondini dysplasia may first become manifest in childhood or early adult life. Some children may pass newborn hearing screen to lose hearing in infancy but others present with a hearing loss at birth. Hearing loss is often progressive and because of the associated widened vestibular aqueduct may progress in a step-wise fashion associated with minor head trauma. Vestibular function is also often affected. While the hearing loss is sensorineural a conductive element may exist probably because of the third window effect of the widened vestibular aqueduct. The Mondini dysplasia can occur in cases of Pendred Syndrome and Branchio-oto-renal syndrome and in other syndromes, but can occur in non-syndromic deafness.

Superior canal (SCD) can affect both hearing and balance to different extents in different people.

Symptoms of SCDS include:

- Autophony – person's own speech or other self-generated noises (e.g. heartbeat, eye movements, creaking joints, chewing) are heard unusually loudly in the affected ear

- Dizziness/ vertigo/ chronic disequilibrium caused by the dysfunction of the superior semicircular canal

- Tullio phenomenon – sound-induced vertigo, disequilibrium or dizziness, nystagmus and oscillopsia

- Pulse-synchronous oscillopsia

- Hyperacusis – the over-sensitivity to sound

- Low-frequency conductive hearing loss

- A feeling of fullness in the affected ear

- Pulsatile tinnitus

- Brain fog

- Fatigue

- Headache/migraine

- Tinnitus – high pitched ringing in the ear

The symptoms of endolymphatic hydrops include the feeling of pressure or fullness in the ears, hearing loss, tinnitus (ringing in the ears) and balance problems. Individuals who have Meniere’s disease have a degree of endolymphatic hydrops that is strong enough to trigger the symptoms of this disease, but individuals with endolymphatic hydrops do not always progress to Meniere’s disease.

Reported symptoms include:

- Sensorineural hearing loss

- Vestibular areflexia

- Hearing impairment

- Vertigo

- Nausea and vomiting

- Head movement-dependent oscillopsia

The hearing loss of Pendred syndrome is often, although not always, present from birth, and language acquisition may be a significant problem if deafness is severe in childhood. The hearing loss typically worsens over the years, and progression can be step-wise and related to minor head trauma. In some cases, language development worsens after head injury, demonstrating that the inner ear is sensitive to trauma in Pendred syndrome; this is as a consequence of the widened vestibular aqueducts usual in this syndrome. Vestibular function varies in Pendred syndrome and vertigo can be a feature of minor head trauma. A goitre is present in 75% of all cases.

Endolymphatic hydrops is a disorder of the inner ear. It consists of an excessive build-up of the endolymph fluid, which fills the hearing and balance structures of the inner ear. Endolymph fluid, which is partly regulated by the endolymph sac, flows through the inner ear and is critical to the function of all sensory cells in the inner ear. In addition to water, endolymph fluid contains salts such as sodium, potassium, chloride and other electrolytes. If the inner ear is damaged by disease or injury, the volume and composition of the endolymph fluid can change, causing the symptoms of endolymphatic hydrops.

Superior canal dehiscence syndrome (SCDS) is a set of hearing and balance symptoms, related to a rare medical condition of the inner ear, known as "superior canal dehiscence". The symptoms are caused by a thinning or complete absence of the part of the temporal bone overlying the superior semicircular canal of the vestibular system. There is evidence that this rare defect, or susceptibility, is congenital. There are also numerous cases of symptoms arising after physical trauma to the head. It was first described in 1998 by Lloyd B. Minor of Johns Hopkins University in Baltimore.

Michel aplasia, also known as complete labyrinthine aplasia (CLA), is a congenital abnormality of the inner ear. It is characterized by the bilateral absence of differentiated inner ear structures and results in complete deafness (anacusis).

Michel aplasia should not be confused with michel dysplasia. It may affect one or both ears.

"Aplasia" is the medical term for body parts that are absent or do not develop properly. In Michel aplasia, the undeveloped (anaplastic) body part is the bony labyrinth of the inner ear. Other nearby structures may be underdeveloped as well.

Symptoms typically include imbalance and visual problems. Dark or unsure situations generally increase this imbalance.The imbalance is worse in the dark or in situations where footing is uncertain. Spinning vertigo is unusual. Oscillopsia, visual symptoms of Bilateral Vestibulopathy only occur when the head is moving. For instance, when driving, a person with Bilateral Vestibulopathy may see very blurry objects. Oscillopsia is often common during walking. Transient visual blurring occurs with quick movements of the head.

Signs and symptoms of AIED are:

- Progressive hearing loss in both ears

- Typically will begin in one ear and gradually affect the other

- Hearing loss may begin suddenly

- Tinnitus (ringing or buzzing in ears)

- Decrease in word recognition capability

- Loss of balance (vestibular symptoms)

- Degree of balance loss can change throughout the course of the disease

Audiometry (measuring ability to hear sounds of a particular pitch) is usually abnormal, but the findings are not particularly specific and an audiogram is not sufficient to diagnose Pendred syndrome. A thyroid goitre may be present in the first decade and is usual towards the end of the second decade. MRI scanning of the inner ear usually shows widened or large vestibular aqueducts with enlarged endolymphatic sacs and may show abnormalities of the cochleae that is known as Mondini dysplasia. Genetic testing to identify the pendrin gene usually establishes the diagnosis. If the condition is suspected, a "perchlorate discharge test" is sometimes performed. This test is highly sensitive, but may also be abnormal in other thyroid conditions. If a goitre is present, thyroid function tests are performed to identify mild cases of thyroid dysfunction even if they are not yet causing symptoms.

The disease is an inherited autosomal dominant disease, but the physiological cause of the dysfunction is still unclear. An acidophyllic mucopolysaccharide-containing substance was discovered, especially in cochleas, maculas, and crista ampullaris of patients with DFNA9 (a chromosome locus), as well as severe degeneration of vestibular and cochlear sensory axons and dendrites. It is suggested that the mucopolysaccharide deposit could cause strangulation of nerve endings.

The maculas and crista ampullaris are what allow for non-visual sensation of head movements. The crista ampullaris resides in the semicircular canals of the inner ear and detects angular acceleration, while the maculas are housed within the vestibule of the inner ear and detect linear acceleration. When affected, these organs can lead to vertigo and nausea because the body would always feel off-balance.

The main symptom of labyrinthitis is severe vertigo. Rapid and undesired eye motion (nystagmus) often results from the improper indication of rotational motion. Nausea, anxiety, and a general ill feeling are common due to the distorted balance signals that the brain receives from the inner ear.

Your physician will make on your history, physical examination or vestibular tests in a rotary chair. There are several different causes of Bilateral Vestibulopathy, including Gentamicin toxicity, but the rotary chair test will determine the effects on both ears. Tests for syphilis, an antibody test for autoimmune inner ear disease or audiograms may be important in determining if you have bilateral vestibulopathy.

Michel aplasia is thought to result from failure of development of the otic placode, due to developmental arrest at the third week of gestation. The common cavity deformity, a confluence of illdefined cochlea and vestibular organ results from a disruption during the fourth and fifth week. An arrest in fifth or sixth week of gestation result in cochlear aplasia or cochlear hypoplasia respectively.

Vertigo is a sensation of spinning while stationary. It is commonly associated with nausea or vomiting, unsteadiness (postural instability), falls, changes to a person's thoughts, and difficulties in walking. Recurrent episodes in those with vertigo are common and frequently impair the quality of life. Blurred vision, difficulty in speaking, a lowered level of consciousness, and hearing loss may also occur. The signs and symptoms of vertigo can present as a persistent (insidious) onset or an episodic (sudden) onset.

Persistent onset vertigo is characterized by symptoms lasting for longer than one day and is caused by degenerative changes that affect balance as people age. Naturally, the nerve conduction slows with aging and a decreased vibratory sensation is common.

Additionally, there is a degeneration of the ampulla and otolith organs with an increase in age. Persistent onset is commonly paired with central vertigo signs and symptoms.

The characteristics of an episodic onset vertigo is indicated by symptoms lasting for a smaller, more memorable amount of time, typically lasting for only seconds to minutes. Typically, episodic vertigo is correlated with peripheral symptoms and can be the result of but not limited to diabetic neuropathy or autoimmune disease.

Vertigo that arises from injury to the balance centers of the central nervous system (CNS), often from a lesion in the brainstem or cerebellum, is called "central" vertigo and is generally associated with less prominent movement illusion and nausea than vertigo of peripheral origin. Central vertigo may have accompanying neurologic deficits (such as slurred speech and double vision), and pathologic nystagmus (which is pure vertical/torsional). Central pathology can cause disequilibrium which is the sensation of being off balance. The balance disorder associated with central lesions causing vertigo is often so severe that many patients are unable to stand or walk.

A number of conditions that involve the central nervous system may lead to vertigo including: lesions caused by infarctions or hemorrhage, tumors present in the cerebellopontine angle such as a vestibular schwannoma or cerebellar tumors, epilepsy, cervical spine disorders such as cervical spondylosis, degenerative ataxia disorders, migraine headaches, lateral medullary syndrome, Chiari malformation, multiple sclerosis, parkinsonism, as well as cerebral dysfunction. Central vertigo may not improve or may do so more slowly than vertigo caused by disturbance to peripheral structures.

Symptoms of ototoxicity include partial or profound hearing loss, vertigo, and tinnitus.

The cochlea is primarily a hearing structure situated in the inner ear. It is the snail-shaped shell containing several nerve endings that makes hearing possible.

Ototoxicity typically results when the inner ear is poisoned by medication that damages the cochlea, vestibule, semi-circular canals, or the auditory/ vestibulocochlear nerve. The damaged structure then produces the symptoms the patient presents with. Ototoxicity in the cochlea may cause hearing loss of the high-frequency pitch ranges or complete deafness, or losses at points between. It may present with bilaterally symmetrical symptoms, or asymmetrically, with one ear developing the condition after the other or not at all. The time frames for progress of the disease vary greatly and symptoms of hearing loss may be temporary or permanent.

The vestibule and semi-circular canal are inner-ear components that comprise the vestibular system. Together they detect all directions of head movement. Two types of otolith organs are housed in the vestibule: the saccule, which points vertically and detects vertical acceleration, and the utricle, which points horizontally and detects horizontal acceleration. The otolith organs together sense the head’s position with respect to gravity when the body is static; then the head’s movement when it tilts; and pitch changes during any linear motion of the head. The saccule and utricle detect different motions, which information the brain receives and integrates to determine where the head is and how and where it is moving.

The semi-circular canals are three bony structures filled with fluid. As with the vestibule, the primary purpose of the canals is to detect movement. Each canal is oriented at right angles to the others, enabling detection of movement in any plane. The posterior canal detects rolling motion, or motion about the X axis; the anterior canal detects pitch, or motion about the Y axis; the horizontal canal detects yaw motion, or motion about the Z axis.

When a medication is toxic in the vestibule or the semi-circular canals, the patient senses loss of balance or orientation rather than losses in hearing. Symptoms in these organs present as vertigo, difficulties walking in low light and darkness, disequilibrium, oscillopsia among others. Each of these problems is related to balance and the mind is confused with the direction of motion or lack of motion. Both the vestibule and semi-circular canals transmit information to the brain about movement; when these are poisoned, they are unable to function properly which results in miscommunication with the brain.

When the vestibule and/or semi-circular canals are affected by ototoxicity, the eye can also be affected. Nystagmus and oscillopsia are two conditions that overlap the vestibular and ocular systems. These symptoms cause the patient to have difficulties with seeing and processing images. The body subconsciously tries to compensate for the imbalance signals being sent to the brain by trying to obtain visual cues to support the information it is receiving. This results in that dizziness and "woozy" feeling patients use to describe conditions such as oscillopsia and vertigo.

Cranial nerve VIII, is the least affected component of the ear when ototoxicity arises, but if the nerve is affected, the damage is most often permanent. Symptoms present similar to those resulting from vestibular and cochlear damage, including tinnitus, ringing of the ears, difficulty walking, deafness, and balance and orientation issues.

The condition is named after the French physician Prosper Ménière, who in an article from 1861 described the main symptoms and was the first to suggest a single disorder for all of the symptoms, in the combined organ of balance and hearing in the inner ear.

The American Academy of Otolaryngology-Head and Neck Surgery Committee on Hearing and Equilibrium (AAO HNS CHE) set criteria for diagnosing Ménière's, as well as defining two sub categories of Ménière's: cochlear (without vertigo) and vestibular (without deafness).

In 1972, the academy defined criteria for diagnosing Ménière's disease as:

1. Fluctuating, progressive, sensorineural deafness.

2. Episodic, characteristic definitive spells of vertigo lasting 20 minutes to 24 hours with no unconsciousness, vestibular nystagmus always present.

3. Tinnitus (ringing in the ears, from mild to severe) Often the tinnitus is accompanied by ear pain and a feeling of fullness in the affected ear. Usually the tinnitus is more severe before a spell of vertigo and lessens after the vertigo attack.

4. Attacks are characterized by periods of remission and exacerbation.

In 1985, this list changed to alter wording, such as changing "deafness" to "hearing loss associated with tinnitus, characteristically of low frequencies" and requiring more than one attack of vertigo to diagnose. Finally in 1995, the list was again altered to allow for degrees of the disease:

1. Certain – Definite disease with histopathological confirmation

2. Definite – Requires two or more definitive episodes of vertigo with hearing loss plus tinnitus and/or aural fullness

3. Probable – Only one definitive episode of vertigo and the other symptoms and signs

4. Possible – Definitive vertigo with no associated hearing loss

In 2015 The International Classification for Vestibular Disorders Committee of the Barany Society published consensus diagnostic criteria in collaboration with the American Academy of Otolaryngology – Head and Neck Surgery, the European Academy of Otology & Neuro-Otology, the Japan Society for Equilibrium Research, and the Korean Balance Society.

Ménière's is characterized by recurrent episodes of vertigo, hearing loss and tinnitus; episodes may be accompanied by headache and a feeling of fullness in the ears.

People may also experience additional symptoms related to irregular reactions of the autonomic nervous system. These symptoms are not symptoms of Meniere's disease per se, but rather are side effects resulting from failure of the organ of hearing and balance, and include nausea, vomiting, and sweating—which are typically symptoms of vertigo, and not of Ménière's. This includes a sensation of being pushed sharply to the floor from behind.

Sudden falls without loss of consciousness (drop attacks) may be experienced by some people.

Labyrinthitis, also known as vestibular neuritis, is inflammation of the inner ear. It results in vertigo and also possible hearing loss or ringing in the ears. It can occur as a single attack, a series of attacks, or a persistent condition that diminishes over three to six weeks. It may be associated with nausea and vomiting. Vestibular neuronitis may also be associated with eye nystagmus.

The cause is often not clear. It may be due to a virus, but it can also arise from bacterial infection, head injury, extreme stress, an allergy, or as a reaction to medication. 30% of affected people had a common cold prior to developing the disease. Either bacterial or viral labyrinthitis can cause permanent hearing loss in rare cases. This appears to result from an imbalance of neuronal input between the left and right inner ears.

Vestibular neuritis affects approximately 35 per million people per year. It typically occurs in those between 30 and 60 years of age. There is no significant gender difference. It derives its name from the labyrinths that house the vestibular system, which senses changes in head position.

PLF is a cause of dizziness, imbalance, and hearing loss—any or all of these symptoms can exist. Vertigo (an illusion of motion) is not common in this disorder. The most common cause of this fistula is head or ear trauma. Rapid increases of intracranial pressure can also result in a PLF. Rarely, these fistulas can be congenital, leading to progressive hearing loss and vertigo in childhood. It has also been a complication of a stapedectomy.

Tumors within the nerve canaliculi initially present with unilateral sensorineural hearing loss, unilateral tinnitus, or disequilibrium (vertigo is rare, on account of the slow growth of neuromas). Speech discrimination out of proportion to hearing loss, difficulty talking on the telephone are frequent accompaniments. Tumors extending into the CPA will likely present with disequilibrium or ataxia depending on the amount of extension on the brainstem. With brainstem extension, midfacial and corneal hypesthesia, hydrocephalus, and other cranial neuropathies become more prevalent.

For example, involvement of CN V from a cerebellopontine mass lesion often results in loss of the ipsilateral (same side of the body) corneal reflex (involuntary blink).

Patients with larger tumours can develop Bruns nystagmus ('dancing eyes') due to compression of the flocculi.