There are four grades of microtia:

- Grade I: A less than complete development of the external ear with identifiable structures and a small but present external ear canal

- Grade II: A partially developed ear (usually the top portion is underdeveloped) with a closed [stenotic] external ear canal producing a conductive hearing loss.

- Grade III: Absence of the external ear with a small peanut-like vestige structure and an absence of the external ear canal and ear drum. Grade III microtia is the most common form of microtia.

- Grade IV: Absence of the total ear or anotia.

The majority (98%) of patients with cholesteatoma have ear discharge or hearing loss or both in the affected ear.

Other more common conditions, such as otitis externa, may also present with these symptoms, but cholesteatoma is much more serious and should not be overlooked. If a patient presents to a doctor with ear discharge and hearing loss, the doctor should consider the patient to have cholesteatoma until the disease is definitely excluded.

Other less common symptoms (all less than 15%) of cholesteatoma may include: pain, balance disruption, tinnitus, ear ache, headaches and bleeding from the ear. There can also be facial nerve weakness.

Balance symptoms in the presence of a cholesteatoma raises the possibility that the cholesteatoma is eroding the balance organs, which form part of the inner ear.

On initial inspection, an ear canal full of discharge may be all that is visible. Until the doctor has cleaned the ear and inspected the entire tympanic membrane, cholesteatoma cannot be either confirmed or excluded.

Once the debris is cleared, cholesteatoma can give rise to a number of appearances. If there is significant inflammation, the tympanic membrane may be partially obscured by an aural polyp. If there is less inflammation, the cholesteatoma may present the appearance of 'semolina' discharging from a defect in the tympanic membrane. The posterior and superior parts of the tympanic membrane are most commonly affected. If the cholesteatoma has been dry, the cholesteatoma may present the appearance of 'wax over the attic'. The attic is just above the ear drum.

The patient may commonly also have clinical signs of conductive hearing loss. Less frequently, there may be signs of imbalance or facial weakness.

If untreated, a cholesteatoma can eat into the three small bones located in the middle ear (the malleus, incus and stapes, collectively called ossicles), which can result in nerve deterioration, deafness, imbalance and vertigo. It can also affect and erode, through the enzymes it produces, the thin bone structure that isolates the top of the ear from the brain, as well as lay the covering of the brain open to infection with serious complications (rarely even death due to brain abscess and septicemia).

Both the acquired as well as the congenital types of the disease can affect the facial nerve that extends from the brain to the face and passes through the inner and middle ear and leaves at the anterior tip of the mastoid bone, and then rises to the front of the ear and extends into the upper and lower face.

Anotia ("no ear") describes a rare congenital deformity that involves the complete absence of the pinna, the outer projected portion of the ear, and narrowing or absence of the ear canal. This contrasts with microtia, in which a small part of the pinna is present. Anotia and microtia may occur unilaterally (only one ear affected) or bilaterally (both ears affected). This deformity results in conductive hearing loss, deafness.

The goal of medical intervention is to provide the best form and function to the underdeveloped ear.

"20% to 40% of children with microtia/anotia will have additional defects that could suggest a syndrome."

Treacher-Collins Syndrome: (TCS) A congenital disorder caused by a defective protein known as treacle, and is characterized by craniofacial deformities; malformed or absent ears are also seen in this syndrome. The effects may be mild, undiagnosed to severe, leading to death. Because the ear defects are much different in this disorder and not only affect the outer ear, but the middle ear as well, reconstructive surgery may not help with the child's hearing and in this case a Bone Anchored Hearing Aid would be best. BAHA will only work, however if the inner ear and nerve are intact.

Goldenhar Syndrome: A rare congenital birth defect that causes abnormalities of facial development. also known as Oculoauricular Dysplasia. The facial anomalies include underdeveloped, asymmetric half of the face. The defect is capable of affecting tissue, muscle, and the underlying bone structure of the side of the face with the abnormality.

Ablepharon-macrostomia Syndrome: (AMS) A rare genetic disorder characterized by various physical anomalies which affect the craniofacial area, the skin, the fingers, and the genitals.

Individuals with Treacher Collins syndrome often have both cleft palate and hearing loss, in addition to other disabilities. Hearing loss is often secondary to absent, small, or unusually formed ears (microtia), and commonly results from malformations of the middle ear. Researchers have found that most patients with Treacher Collins syndrome have symmetric external ear canal abnormalities and symmetrically dysmorphic or absent ossicles in the middle ear space. Inner ear structure is largely normal. Most patients show a moderate hearing impairment or greater, and the type of loss is generally a conductive hearing loss. Patients with Treacher Collins syndrome exhibit hearing losses similar to those of patients with malformed or missing ossicles (Pron "et al.", 1993).

Cholesteatoma is a destructive and expanding growth consisting of keratinizing squamous epithelium in the middle ear and/or mastoid process. Although cholesteatomas are not classified as either tumors or cancers, they can still cause significant problems because of their erosive and expansile properties resulting in the destruction of the bones of the middle ear (ossicles), as well as their possible spread through the base of the skull into the brain. They are also often infected and can result in chronically draining ears.

Endaural phenomena are sounds that are heard without any external acoustic stimulation. Endaural means "in the ear". Phenomena include transient ringing in the ears (that sound like sine tones), white noise-like sounds, and subjective tinnitus. Endaural phenomena need to be distinguished from otoacoustic emissions, in which a person's ear emits sounds. The emitter typically cannot hear the sounds made by his or her ear. Endaural phenomena also need to be distinguished from auditory hallucinations, which are sometimes associated with psychosis.

Persons with Pierre Robin sequence (PRS) are at greater risk for hearing impairment than persons with cleft lip and/or palate without PRS. One study showed an average of 83% hearing loss in PRS, compared to 60% in cleft individuals without PRS (Handzic "et al.", 1995). Similarly, PRS individuals typically exhibit conductive, bilateral hearing losses that are greater in degree than in cleft individuals without PRS. Middle ear effusion is generally apparent, with no middle ear or inner ear malformations. Accordingly, management by ear tubes (myringotomy tubes) is often effective and may restore normal levels of hearing (Handzic "et al.", 1995).

Primary symptoms:

- sounds or speech becoming dull, muffled or attenuated

- need for increased volume on television, radio, music and other audio sources

- difficulty using the telephone

- loss of directionality of sound

- difficulty understanding speech, especially women and children

- difficulty in speech discrimination against background noise (cocktail party effect)

Secondary symptoms:

- hyperacusis, heightened sensitivity to certain volumes and frequencies of sound, resulting from "recruitment"

- tinnitus, ringing, buzzing, hissing or other sounds in the ear when no external sound is present

- vertigo and disequilibrium

Usually occurs after age 50, but deterioration in hearing has been found to start very early, from about the age of 18 years. The ISO standard 7029 shows expected threshold changes due purely to age for carefully screened populations (i.e. excluding those with ear disease, noise exposure etc.), based on a meta-analysis of published data. Age affects high frequencies more than low, and men more than women. One early consequence is that even young adults may lose the ability to hear very high frequency tones above 15 or 16 kHz. Despite this, age-related hearing loss may only become noticeable later in life. The effects of age can be exacerbated by exposure to environmental noise, whether at work or in leisure time (shooting, music, etc.). This is noise-induced hearing loss (NIHL) and is distinct from presbycusis. A second exacerbating factor is exposure to ototoxic drugs and chemicals.

Over time, the detection of high-pitched sounds becomes more difficult, and speech perception is affected, particularly of sibilants and fricatives. Patients typically express a decreased ability to understand speech. Once the loss has progressed to the 2-4kHz range, there is increased difficulty understanding consonants. Both ears tend to be affected. The impact of presbycusis on communication depends on both the severity of the condition and the communication partner.

Presbycusis (also spelled presbyacusis, from Greek "presbys" “old” + "akousis" “hearing”), or age-related hearing loss, is the cumulative effect of aging on hearing. It is a progressive and irreversible bilateral symmetrical age-related sensorineural hearing loss resulting from degeneration of the cochlea or associated structures of the inner ear or auditory nerves. The hearing loss is most marked at higher frequencies. Hearing loss that accumulates with age but is caused by factors other than normal aging (nosocusis and sociocusis) is not presbycusis, although differentiating the individual effects of distinct causes of hearing loss can be difficult.

The cause of presbycusis is a combination of genetics, cumulative environmental exposures and pathophysiological changes related to aging. At present there are no preventative measures known; treatment is by hearing aid or surgical implant.

Presbycusis is the most common cause of hearing loss, afflicting one out of three persons by age 65, and one out of two by age 75. Presbycusis is the second most common illness next to arthritis in aged people.

Many vertebrates such as fish, birds and amphibians do not suffer presbycusis in old age as they are able to regenerate their cochlear sensory cells, whereas mammals including humans have genetically lost this regenerative ability.

SSHL is diagnosed via pure tone audiometry. If the test shows a loss of at least 30db in three adjacent frequencies, the hearing loss is diagnosed as SSHL. For example, a hearing loss of 30db would make conversational speech sound more like a whisper.

Only 10 to 15 percent of the cases diagnosed as SSHL have an identifiable cause. Most cases are classified as idiopathic, also called sudden idiopathic hearing loss (SIHL) and idiopathic sudden sensorineural hearing loss (ISSHL or ISSNHL) The majority of evidence points to some type of inflammation in the inner ear as the most common cause of SSNHL.

- Viral - The swelling may be due to a virus. A herpes type virus is believed to be the most common cause of sudden sensorineural hearing loss. The herpes virus lays dormant in our bodies and reactivates for an unknown reason.

- Vascular ischemia of the inner ear or cranial nerve VIII (CN8)

- Perilymph fistula, usually due to a rupture of the round or oval windows and the leakage of perilymph. The patient will usually also experience vertigo or imbalance. A history of trauma is usually present and changes to hearing or vertigo occur with alteration in intracranial pressure such as with straining; lifting, blowing etc.

- Autoimmune - can be due to an autoimmune illness such as systemic lupus erythematosus, granulomatosis with polyangiitis

Most branchial cleft cysts present as a smooth, slowly enlarging lateral neck mass that may increase in size after an upper respiratory tract infection. The fistulas, when present, are asymptomatic, but may become infected.

Auditory fatigue is defined as a temporary loss of hearing after exposure to sound. This results in a temporary shift of the auditory threshold known as a "temporary threshold shift" (TTS). The damage can become permanent (permanent threshold shift, PTS) if sufficient recovery time is not allowed for before continued sound exposure. When the hearing loss is rooted from a traumatic occurrence, it may be classified as noise-induced hearing loss, or NIHL.

There are two main types of auditory fatigue, short-term and long-term. These are distinguished from each other by several characteristics listed individually below.

Short-term fatigue

- full recovery from TTS can be achieved in approximately two minutes

- the TTS is relatively independent of exposure duration

- TTS is maximal at the exposure frequency of the sound

Long-term fatigue

- recovery requires a minimum of several minutes but can take up to several days

- dependent on exposure duration and noise level

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.

Symptoms in people with Treacher Collins syndrome vary. Some individuals are so mildly affected that they remain undiagnosed, while others have moderate to severe facial involvement and life-threatening airway compromise. Most of the features of TCS are symmetrical and are already recognizable at birth.

The most common symptom of Treacher Collins syndrome is underdevelopment of the lower jaw and underdevelopment of the zygomatic bone. This can be accompanied by the tongue being retracted. The small mandible can result in a poor occlusion of the teeth or in more severe cases, trouble breathing or swallowing. Underdevelopment of the zygomatic bone gives the cheeks a sunken appearance.

The external ear is sometimes small, rotated, malformed, or absent entirely in people with TCS. Symmetric, bilateral narrowing or absence of the external ear canals is also described. In most cases, the bones of the middle ear and the middle ear cavity are misshapen. Inner ear malformations are rarely described. As a result of these abnormalities, a majority of the individuals with TCS have conductive hearing loss.

Most affected people also experience eye problems, including colobomata (notches) in the lower eyelids, partial or complete absence of eyelashes on the lower lid, downward angled eyelids, drooping of upper and lower eyelids, and narrowing of the tear ducts. Vision loss can occur and is associated with strabismus, refractive errors, and anisometropia. It can also be caused by severely dry eyes, a consequence of lower eyelid abnormalities and frequent eye infections.

Although an abnormally shaped skull is not distinctive for Treacher Collins syndrome, brachycephaly with bitemporal narrowing is sometimes observed. Cleft palate is also common.

Dental anomalies are seen in 60% of affected people, including tooth agenesis (33%), discoloration (enamel opacities) (20%), malplacement of the maxillary first molars (13%), and wide spacing of the teeth. In some cases, dental anomalies in combination with mandible hypoplasia result in a malocclusion. This can lead to problems with food intake and the ability to close the mouth.

Less common features of TCS may add to an affected person's breathing problems, including sleep apnea. Choanal atresia or stenosis is a narrowing or absence of the choanae, the internal opening of the nasal passages. Underdevelopment of the pharynx, can also narrow the airway.

Features related to TCS that are seen less frequently include nasal deformities, high-arched palate, macrostomia, preauricular hair displacement, cleft palate, hypertelorism, notched upper eyelid, and congenital heart defects.

The general public may associate facial deformity with developmental delay and intellectual disability, but more than 95% of people affected with TCS have normal intelligence. The psychological and social problems associated with facial deformity can affect quality of life in people with TCS.

A branchial cleft cyst is a cyst in the skin of the lateral part of the neck. It can but does not necessarily have an opening to the skin surface called a fistula. The cause is usually a developmental abnormality arising in the early prenatal period, typically failure of obliteration of the second branchial cleft, i.e. failure of fusion of the second and third branchial arches. Less commonly, the cysts can develop from the first, third, or fourth clefts, and their location and the location of associated fistulas differs accordingly.

King–Kopetzky syndrome is an auditory disability characterised by difficulty in hearing speech in the presence of background noise in conjunction with the finding of normal hearing test results.

It is an example of auditory processing disorder (APD) or "auditory disability with normal hearing (ADN)".

King–Kopetzky syndrome patients have a worse Social Hearing Handicap index (SHHI) than others, indicating they suffer a significant degree of speech-hearing disability.

The condition is named after Samuel J. Kopetzky, who first described the condition in 1948, and P. F. King, who first discussed the aetiological factors behind it in 1954.

TTS imperceptibly gives way to PTS.

In addition to hearing loss, other external symptoms of an acoustic trauma can be:

- Tinnitus

- Some pain in the ear

- Hyperacusis

- Dizziness or vertigo; in the case of vestibular damages, in the inner-ear

Due to variations in study designs, data on the course of tinnitus showed few consistent results. Generally the prevalence increased with age in adults, whereas the ratings of annoyance decreased with duration.

Tinnitus can be perceived in one or both ears or in the head. It is the description of a noise inside a person’s head in the absence of auditory stimulation. The noise can be described in many different ways.

It is usually described as a ringing noise but, in some patients, it takes the form of a high-pitched whining, electric buzzing, hissing, humming, tinging or whistling sound or as ticking, clicking, roaring, "crickets" or "tree frogs" or "locusts (cicadas)", tunes, songs, beeping, sizzling, sounds that slightly resemble human voices or even a pure steady tone like that heard during a hearing test. It has also been described as a "whooshing" sound because of acute muscle spasms, as of wind or waves. Tinnitus can be intermittent or continuous: in the latter case, it can be the cause of great distress. In some individuals, the intensity can be changed by shoulder, head, tongue, jaw or eye movements. Most people with tinnitus have some degree of hearing loss.

The sound perceived may range from a quiet background noise to one that can be heard even over loud external sounds. The specific type of tinnitus called pulsatile tinnitus is characterized by hearing the sounds of one's own pulse or muscle contractions, which is typically a result of sounds that have been created by the movement of muscles near to one's ear, or the sounds are related to blood flow of the neck or face.

It seems that somatic anxiety and situations of stress may be determinants of speech-hearing disability.

Some studies indicated an increased prevalence of a family history of hearing impairment in these patients. The pattern of results is suggestive that King-Kopetzky patients may be related to conditions of autosomal dominant inheritance.

Subsequent to diagnosis of sensorineural hearing loss, and differential diagnosis of retrocochlear or neural etiologies,

radiological assessment of the CPA is performed to assess the presence of anatomical retrocochlear lesions.

This uncommon tumor accounts for less than 2% of all ear tumors. While patients present with symptoms related to the middle ear cavity location of the tumor, the tumor may expand into the adjacent structures (external auditory canal, mastoid bone, and eustachian tube). Patients come to clinical attention with unilateral (one sided) hearing loss, usually associated with decreased auditory acuity, and particularly conductive hearing loss if the ossicular bone chain (middle ear bones) is involved. Tinnitus (ringing), otitis media, pressure or occasionally ear discharge are seen. At the time of otoscopic exam, the tympanic membrane is usually intact, with a fluid level or mass noted behind the ear drum. Even though this is a "neuroendocrine" type tumor, there is almost never evidence of neuroendocrine function clinically or by laboratory examination.