Ear, Hearing, and Facial Nerve Evaluation

Anatomy and Physiology

Anatomy

The temporal bone contains the structures of the external, middle, and inner ear, which are essential for hearing and balance.[1] 

External ear

• The auricle is outside the temporal bone.
• The external auditory canal is housed within the tympanic part of the temporal bone.
• The external ear canal (EAC) is bordered laterally by the external ear and medially by the tympanic membrane.
• The lateral one-third of the EAC consists of fibrocartilage, while the medial two-thirds consist of bone and are formed by the tympanic part of the temporal bone.
• The fibrocartilaginous EAC includes the fissures of Santorini, which enable abnormalities in the EAC to extend into the nearby parotid space inferiorly.

Middle ear

• The middle ear includes the tympanic cavity, ossicles, and Eustachian tube, all located within the tympanic and petrous portions of the temporal bone.
• The middle ear cavity is an air-filled space located within the petrous part of the temporal bone that houses the ossicular chain.
• The ossicular chain consists of 3 bones: the malleus (with its head, neck, anterior process, lateral process, and manubrium attached to the tympanic membrane), the incus (including the body, short process, long process, and lenticular process), and the stapes (comprising the head or capitellum, anterior crus, posterior crus, and footplate).

Inner ear

• The inner ear includes the cochlear and vestibular systems, contained within the otic capsule.
• The otic capsule is the densest part of the petrous portion of the temporal bone and encases the osseous labyrinth, including the vestibule, semicircular canals, and cochlea.
• The osseous labyrinth encases the membranous labyrinth, which contains endolymph and includes the cochlear duct, utricle, saccule, semicircular ducts, endolymphatic duct, and sac. The osseous labyrinth is surrounded by the perilymphatic labyrinth, which contains perilymph.

The temporal bone is adjacent to the skull base, brain, and major blood vessels. The internal carotid artery passes through the petrous part of the temporal bone, located anterior to the cochlea and Eustachian tube. In contrast, the jugular foramen, which contains the internal jugular vein and cranial nerves IX through XI, lies posteriorly. The anatomical features of the internal carotid artery and its origin at the carotid bifurcation are particularly important for surgical planning. Factors such as the position of the bifurcation, measurements of the internal carotid artery, abnormal or tortuous pathways, and detailed anatomy of the carotid sinus should be carefully considered.[2] The close relationship of the temporal bone to the brainstem, cerebellum, and major vessels explains why temporal bone pathology can lead to neurologic deficits, hemorrhage, and venous thrombosis.[3]         

The internal auditory canal is a passage within the petrous part of the temporal bone, lined with dura mater and filled with cerebrospinal fluid (CSF) in the subarachnoid space. This canal contains the facial nerve, the facial nerve intermedius, the vestibulocochlear nerve complex, and the labyrinthine artery. The facial nerve canal is distinctly outlined along its entire path within the temporal bone.

Physiology

• The external ear includes the auricle (pinna) and the EAC. The auricle is made of cartilage and helps gather and direct sound toward the EAC. The EAC is a tube composed of cartilage and bone, lined with skin that contains ceruminous glands, which secrete earwax (cerumen) to shield the canal. 
• The middle ear is an air-filled space that carries sound from the outer ear to the inner ear. This area includes the tympanic membrane (eardrum) and 3 small bones called ossicles (malleus, incus, and stapes). These ossicles amplify and pass sound vibrations inward. The Eustachian tube links the middle ear to the nasopharynx, helping to balance pressure and drain fluid secretions. 
• The inner ear includes the cochlea for hearing and the vestibular system for balance. The cochlea is a spiral-shaped structure that transforms sound vibrations into neural signals. The vestibular system comprises the semicircular canals and otolith organs, which sense rotational and linear movements, respectively. 
• The facial nerve (cranial nerve VII) traverses the middle ear and is at risk during ear surgical procedures. The vestibulocochlear nerve (cranial nerve VIII) carries auditory and balance signals to the brain. Blood supply to the ear comes from branches of the external and internal carotid arteries, with venous drainage through the sigmoid sinus and internal jugular vein. 
• Sound transduction involves converting sound waves into neural signals.[4] Sound enters the outer ear, vibrates the tympanic membrane, and is amplified by the ossicles in the middle ear. In the inner ear, hair cells in the cochlea transform these vibrations into electrical signals that the auditory nerve transmits to the brain. The inner ear also helps maintain balance through the vestibular system. Disruption at any stage of this process can lead to hearing loss or balance and equilibrium issues.[5][4]
  • In a pure-tone hearing test, an audiologist uses an audiometer to evaluate an individual's ability to detect sounds across various frequencies and intensities. Hearing thresholds are determined as the lowest sound level at which an individual can perceive a tone 50% of the time the tone is presented.
  • Individuals with sensorineural hearing loss usually have no findings on imaging, whereas those with conductive hearing loss are generally expected to show abnormalities on temporal bone CT.

Indications

An ear examination is recommended for several reasons, including:

Hearing loss 

• Conduct an immediate examination and audiometry for sudden hearing loss.
• Treat patients urgently if the hearing loss is sensorineural to enhance recovery.
• Evaluate progressive hearing loss for potential causes such as otosclerosis, Ménière disease, or other factors.
• Consider ruling out vestibular schwannoma or retrocochlear pathology in patients with asymmetrical hearing loss.
• Evaluate for cerumen impaction, middle ear fluid, or sensorineural hearing loss in patients with difficulty hearing.[6]

Pain (Otalgia) 

• Assess symptoms such as fever, swelling, or discharge carefully.
• Consider otitis media or otitis externa when ear pain is accompanied by fever.
• Consider Eustachian tube dysfunction or temporomandibular joint issues in patients with pain on chewing or swallowing.
• Recognize pain with tragus or pinna manipulation as a typical finding of otitis externa.[7]

Discharge (otorrhea) and infection 

• Otorrhea: Suspect otitis externa, otitis media, or chronic suppurative otitis media.
• Blood-tinged or pus-like discharge signifies infection or injury.
• Chronic ear discharge: Assess for cholesteatoma or chronic otitis media.[8]

Balance and vertigo 

• Vertigo or dizziness: Assess for these symptoms, particularly when accompanied by hearing loss, tinnitus, or a feeling of fullness in the ear.
• Episodic vertigo: Suspect Ménière disease.
• Persistent imbalance: Assess for vestibular disorders or central causes.[9][10][11]

Tinnitus and noise exposure  

• Tinnitus: Assess for tinnitus, especially if unilateral, pulsatile, or accompanied by hearing loss.
• Pulsatile tinnitus: Consider vascular or structural lesions; examine the patient first, then pursue imaging.
• Persistent tinnitus: Assess for Ménière disease, otosclerosis, or other underlying causes.[12]

Foreign body and trauma

• Foreign body in the ear: Common in children or with ongoing symptoms.
• Ear trauma: Including barotrauma or blast injury.
• Perforated tympanic membrane: Evaluate and manage appropriately.[7]

Cerumen impaction and ear canal issues

• Cerumen impaction: Patients often present with symptoms or canal blockage.
• Hearing aid problems: Inspect for cerumen or other canal issues.
• Ear canal stenosis: Assess for congenital or acquired causes such as external auditory osteoma.[7][13]

Contraindications

Absolute Contraindications

• Lack of patient or family consent
• Known tympanic membrane perforation or prior ear surgery
• Ear canal stenosis, acquired or congenital

Relative Contraindications

• Active ear discharge (otorrhea), infection, bleeding, or suspected cerebrospinal fluid leakage
• Structural barriers, such as a foreign body
• Patients unable to tolerate examination
• Severe pain or discomfort with examination [14][15]

Equipment

Pneumatic Otoscopy

Pneumatic otoscopy enables visualization of the ear canal and tympanic membrane and assesses the tympanic membrane's mobility in response to pressure changes.[6][16] Requirements include the following:

• A bright light
• Multiple speculum sizes
• An airtight seal in the ear canal
• A digital otoscope (if available) to provide high-definition visualization, enable documentation, and facilitate patient education through images and video. Many devices are compatible with smartphones and may offer telehealth capabilities [17]
• A biocular microscope with a focal distance of approximately 200 mm and magnification of 4 to 25 times

Cerumen Management Tools

• Aural specula, in various sizes
• Hooks or loops
• Jobson Horne probes, double-ended currettes
• A suction device using 300 mm Hg suction pressure with a reservoir and built-in filter
• Irrigation supplies
• Lukewarm water (37 °C)
• Kidney dishes
• Absorbent sheeting
• Pressure-controlled ear irrigation device

Tuning Forks for Weber and Rinne Hearing Tests 

• A 512 Hz tuning fork is preferred to distinguish between conductive and sensorineural hearing loss because it offers an ideal balance of tone, durability, and resonance.
• A 256 Hz tuning fork as an alternative, although clinicians more commonly use it in neurology to assess vibration sensation. In hearing tests, a 256 Hz tuning fork can provide more tactile vibration than sound.
• Tuning forks are made from lightweight, nonmagnetic aluminum. Please see StatPearls' companion reference, "Weber Test," for further information.

Personnel

An effective ear examination mainly depends on the examiner and the patient. When assessing a child, involving the child's parent and experienced clinical staff or a play specialist can enhance compliance. No anesthesia is necessary or advised. Proper positioning is crucial to performing an ear examination.

Preparation

An adult individual or a cooperative child should be seated in a chair that appropriately supports comfort and body size. Before the ear examination, clinicians should obtain a complete medical history from the individual or their parent or guardian. When discussing ear-related issues, clinicians should ask about symptoms such as discharge, pain, hearing loss, tinnitus, or dizziness. Asking which ear the individual perceives as having better hearing is also useful, since the standard practice is to examine the better ear first. Providing a clear, respectful explanation of the examination process can greatly reduce discomfort or confusion, especially during assessments that require cooperation, such as tuning fork tests. Additionally, clinicians should follow the World Health Organization guidelines on hand hygiene, which is key to reducing the risk of cross-contamination and ensuring individual safety.[16][18] Hand-washing should be performed:

• Before and after touching a patient
• Before handling an invasive device for patient care, regardless of whether gloves are worn
• After contact with body fluids or excretions, mucous membranes, nonintact skin, or wound dressings
• If moving from a contaminated body site to another body site during care of the same patient, such as when examining one ear and then the other.
• After contact with inanimate surfaces and objects (including medical equipment) in the immediate vicinity of a patient
• After removing sterile or nonsterile gloves [16]

Technique or Treatment

A step-by-step ear examination begins with the external structures and proceeds inward. The examination involves inspection, palpation, and otoscopy to assess the auricle, external canal, and tympanic membrane. After this initial assessment, pneumatic otoscopy or tympanometry may be performed to evaluate the middle ear. Performing and interpreting otoscopy is an essential clinical skill. However, the level of training and experience can vary significantly, which impacts the accuracy of diagnoses.[19]

External Ear

• Inspection: Inspect the auricle for deformity, lesions, erythema, edema, scars, pits, or discharge.
• Palpation: Examine the tragus and pinna for tenderness, as this may indicate otitis externa.
• Postauricular region: Check for signs of swelling, redness (erythema), or increased fluid (fluctuance), which could indicate mastoiditis.

External Auditory Canal

• Otoscopy: Use a bright, focused light and choose the largest speculum that fits comfortably.
• Cerumen assessment: If cerumen is causing symptoms or obstructing visibility, it should be removed.
• Canal findings: Observe for any signs of swelling (edema or bony abnormalities), redness (erythema), drainage (whether clear, pus-like, or bloody), debris, or foreign objects.

Tympanic Membrane 

• Inspection: Evaluate color, position, integrity (perforation or retraction pockets), landmarks, and mobility.
• Pneumatic otoscopy: Assess mobility; decreased motion indicates effusion or otitis media with effusion.
• Key findings: Bulging, retraction, perforation, tympanosclerosis, or air-fluid levels.

Middle Ear Assessment 

To perform pneumatic otoscopy, use a bright otoscope with a pneumatic bulb and a speculum that fits snugly in the ear canal. Check for an airtight seal, then gently squeeze and release the bulb to apply positive and negative pressure, observing the mobility of the tympanic membrane. Reduced or absent motion can indicate middle ear effusion or otitis media. Pneumatic otoscopy is quick, noninvasive, and improves diagnostic accuracy for middle ear disease. 

• Tympanometry: An objective adjunct when pneumatic otoscopy is uncertain.
• Acoustic reflex testing: An objective measure of involuntary stapedius muscle contraction in response to high-intensity sounds (70-100 dB SPL).
• Potential middle ear findings: Effusion, tympanic membrane retraction or perforation, or ossicular chain abnormalities.

Hearing assessment

The patient should be assessed for sudden hearing loss, persistent tinnitus, vertigo, or asymmetric loss. Many clinical conditions, whether acquired or congenital, can cause hearing loss, which may be conductive, sensorineural, or mixed. Conductive hearing loss occurs when vibrations are blocked from reaching the cochlea, as in cases of ossicular disruption or tympanic membrane perforation. Sensorineural hearing loss involves damage to the cells within the cochlea or pathology of the vestibulocochlear nerve.

Tuning-fork tests: 

In primary care, the Weber and Rinne tests help the clinician distinguish between conductive and sensorineural hearing loss, especially when audiometry is unavailable. These tests guide the need for further examination, investigation, and treatment. The Weber and Rinne tuning fork tests can help confirm audiometric results, especially when the audiogram does not match clinical findings. However, these tests do not replace pure-tone audiometry.

• The Weber test: Use a 512 Hz tuning fork and perform the Weber test at the midline of the forehead to determine if the sound localizes to the affected ear (indicating conductive hearing loss) or away from it (suggesting sensorineural loss).
  • In normal hearing or symmetrical hearing loss, sound is heard in the center.
  • In asymmetrical sensorineural hearing loss, sound is heard loudest in the normal ear.
  • In asymmetrical conductive hearing loss, sound is heard loudest in the affected ear.
• The Rinne test: The Rinne test differentiates between air-conduction and bone-conduction sound transmission. Clinicians should perform a Rinne test together with a Weber test to detect sensorineural hearing loss.
  • Technique: 
    • Initiate the tuning fork's vibration, then place it on the patient's mastoid process of the tested ear.
    • Ask the patient to cover the opposite ear with their hand.
    • Ask the patient to report when the sound is no longer audible.
    • After the patient can no longer hear the tuning fork placed on the mastoid process, move the vibrating tuning fork adjacent to the ear canal with the tines oriented perpendicular to the ear canal, approximately 3 to 4 cm from the ear.
    • The patient should indicate when they can no longer hear the sound conducted through the air.[20]
  • Normal finding: Air conduction is louder than bone conduction. The patient should be able to hear the tuning fork sound adjacent to their ear, which persists approximately twice as long as the sound heard over their mastoid process. This finding is considered a positive test result.
  • Abnormal finding: Bone conduction is louder than air conduction. The patient cannot hear sounds conducted through the air after the fork is moved from the mastoid process. This finding suggests conductive hearing loss and is called a negative test result.
  • Clinical significance  
    • The patient has a positive result on that side if the ossicular chain is functioning as it should (acting as an amplifier). If bone conduction through the mastoid process is louder than air conduction, the patient has a negative Rinne test result. This is always an abnormal finding.
    • If the patient has a negative Rinne test result, air vibration is not transmitted across the external auditory canal, the tympanic membrane, the ossicular chain, or the oval window.
    • Possible causes of an abnormal Rinne test include earwax impaction, otitis externa, foreign body in the ear canal, tympanic membrane perforation, acute otitis media, serous otitis media, and otosclerosis.
    • A patient with profound sensorineural deafness may have a false-negative Rinne test result. With complete loss of innervation to the affected ear, the patient does not hear anything from the tuning fork on the mastoid or near the canal. The sound transmits through their skull to the ear on the other side, and they may be unable to identify in which ear they hear the sound. The results suggest that bone conduction is better than air conduction, but the ear is nonfunctional. Performing the Weber test can distinguish between a true Rinne-negative result and a false Rinne-negative result. Please see StatPearls' companion reference, "Weber Test," and "Rinne Test," for further information.[21][22][22]

• Pure-tone audiometry: The gold standard for measuring hearing loss and confirming its type. The Rinne test complements the Weber test. Both are screening tests that do not replace formal audiometry. 

Facial Nerve Function Testing 

The facial nerve has a complex infratemporal course that runs through the middle ear. Consequently, various otological conditions, including cholesteatoma, surgical procedures, trauma, and middle ear infections, can lead to facial nerve palsy. To assess facial nerve function, the most common method is to evaluate the branchiomotor component, which supplies the muscles of facial expression. The examiner should ask the individual to lift their eyebrows, squeeze their eyes shut, resist forceful eye opening, puff out their cheeks, and show their teeth.

The motor portion, or the facial nerve proper, supplies all the muscles of the face. The main muscles include the frontalis, orbicularis oculi, buccinator, orbicularis oris, platysma, the posterior belly of the digastric, and the stapedius muscle. In nuclear or infranuclear (peripheral) lesions, findings include partial to complete facial paralysis with smoothing of the brow, an open eye, a flat nasolabial fold, and drooping of the mouth on the same side as the lesion. Supranuclear (central) lesions spare the brow and eyelid muscles; instead, findings include flattening of the nasolabial fold and drooping of the mouth on the opposite side of the lesion.

Facial nerve palsies are a common and important presentation for otolaryngologists and, more broadly, for general medical clinicians. The severity of facial nerve paralysis is assessed using the House-Brackmann grading system.[23] The House-Brackmann grading system is a 6-point scale (1 through 6) that evaluates facial nerve function, with grade 1 representing normal function and grade 6 indicating complete paralysis. The House-Brackmann grading system is widely used to assess severity, track recovery, and guide treatment decisions in conditions such as Bell palsy, Ramsay Hunt syndrome, and postoperative facial palsy. The scale is straightforward and practical for clinical use, but differences between raters are common. Consequently, consistent clinical training and repeated assessments are needed to help improve reliability.

House-Brackmann grading system 

• Grade I: Normal facial function
• Grade II: Slight weakness, normal symmetry at rest, and slight synkinesis
• Grade III: Moderate weakness, normal symmetry at rest, but noticeable asymmetry with movement
• Grade IV: Moderately severe weakness, noticeable asymmetry at rest, and incomplete eye closure
• Grade V: Severe weakness, barely perceptible motion, and incomplete eye closure
• Grade VI: Total paralysis, no movement

Importantly, the difference between grades III and IV is the presence of eye closure. Additional tests used to clinically assess the facial nerve lesion may include the blink test (corneal reflex), Schirmer test (assessing lacrimation), stapedial test, salivary test, and taste test. These are beyond the scope of a typical ear examination. Please see StatPearls' companion reference, "Facial Nerve Anatomy and Clinical Applications," for further information.[24][25] Clinicians should record findings and link them to symptoms to ensure effective care. Clinicians should arrange follow-up for persistent symptoms, abnormal results, or suspected serious conditions.

Clinical Significance

A comprehensive ear examination is crucial for diagnosing common issues such as cerumen impaction, otitis media, otitis externa, and sudden sensorineural hearing loss. The examination helps determine appropriate treatment, prevents complications, and is essential after abnormal hearing screenings to identify correctable problems and minimize unnecessary referrals. Additionally, a comprehensive ear examination aids in the early detection of serious conditions such as cholesteatoma or vestibular schwannoma. Conducting a thorough ear examination enhances individual outcomes, lowers health care costs, and ensures the timely treatment of reversible conditions. Accurate diagnosis facilitates the identification of common ear conditions, including cerumen impaction, otitis media, otitis externa, tympanic membrane perforation, and cholesteatoma, as well as serious pathologies, including vestibular schwannoma, meningioma, and malignant neoplasms of the temporal bone.

The examination guides appropriate treatment decisions, such as cerumen removal, antibiotic or steroid drops for acute otitis media, aural toilet with acidifying or antimicrobial agents, and analgesia for acute otitis externa, as well as urgent, time-sensitive evaluation and definitive management for suspected sudden sensorineural hearing loss, with audiometry. Furthermore, early detection of conditions such as cholesteatoma or malignant tumors helps prevent serious complications.

Enhancing Healthcare Team Outcomes

According to the Centers for Medicare and Medicaid Services, "the purpose of a medical history and physical examination is to determine whether there is anything in the patient's overall condition that would affect the planned course of the patient's treatment, such as a medication allergy, or a new or existing comorbid condition that requires additional interventions to reduce risk to the patient." [CMS. CMS Interpretive Guidelines §482.22(c)(5)(i)] Ear problems are very common, especially in children, and can range from mild to severe. Conducting a thorough ear examination is a vital part of health care, often beginning during the first visit to a clinic, urgent care center, hospital, or emergency department. Despite technological advances such as improved visualization methods, interpreting ear examination results can still vary among observers. Early detection and treatment of ear issues depend largely on this interpretation.

An interdisciplinary approach is necessary to treat patients with ear conditions and ensure patient-centered care and better outcomes. Primary care clinicians, pediatricians, otolaryngologists, neurologists, emergency clinicians, critical care specialists, advanced practice clinicians, nurses, audiologists, speech pathologists, pharmacists, and other health care team members involved in these cases should have the essential skills and knowledge to diagnose and treat ear disorders and hearing loss. Additional team members may include geneticists for congenital conditions and social workers for resource support. Recognizing various clinical signs and understanding the subtleties of diagnostic techniques extend beyond the ear or hearing, such as assessing facial muscle movement. Research findings indicate that these teams improve early detection and treatment of ear-related conditions.

Contemporary health care delivery requires effective, cooperative, and collaborative teamwork to meet patients' complex needs. These practices involve selecting the right team members, enhancing team dynamics, and fostering a team-oriented approach.[26] A strategic approach is also essential, using evidence-based methods to enhance treatment plans and minimize adverse effects. Ethical principles must guide decision-making, ensuring informed consent and respecting patient autonomy in choosing care. Each clinician must be aware of their responsibilities and contribute unique skills to the patient's care plan, promoting a team-based approach. Clear communication among team members is crucial for smooth information sharing and collaborative decisions. Coordinating care is vital for guiding the patient seamlessly from diagnosis to treatment and follow-up, reducing errors and increasing safety. By adopting these core principles—skill, strategy, ethics, responsibility, communication, and coordination—clinicians can deliver patient-centered care, ultimately improving patient outcomes and strengthening team performance in the treatment of ear disorders and hearing health.