Hearing Loss

Sensorineural hearing loss (SNHL) is the most prevalent form of hearing loss, accounting for approximately 90% of all cases. It occurs when the tiny hair cells inside the cochlea (inner ear) or the auditory nerve itself are damaged or missing. These hair cells do not regenerate, which is why sensorineural hearing loss is typically permanent.

The condition ranges from mild speech intelligibility difficulties all the way to complete deafness. In its early stages, sensorineural hearing loss often manifests as difficulty understanding speech in background noise — many people notice it first in restaurants or group conversations.

• Age-related hearing loss (presbycusis) — begins around age 50–60
• Noise exposure — 85dB+ over 6–8 hours/day
• Circulatory disorders (diabetes, arteriosclerosis)
• Metabolic illnesses (thyroid dysfunction)
• Sudden hearing loss (a subtype)
• Ototoxic medications
• Genetic factors

• Difficulty understanding speech in noise
• Sounds seem muffled or distant
• Asking people to repeat themselves often
• Tinnitus (ringing or buzzing in ears)
• Trouble hearing high-pitched sounds
• Social withdrawal and fatigue from listening

An ENT specialist or audiologist diagnoses sensorineural hearing loss through a series of tests. A mirror examination first rules out outer ear causes. Pure-tone audiometry then maps the patient's hearing thresholds across frequencies — in SNHL, both bone conduction and air conduction curves are shifted to higher decibels, but neither shows a gap between the two (unlike conductive hearing loss).

Additional tests include impedance audiometry (to assess eardrum and ossicle function), otoacoustic emission (OAE) testing (which measures hair cell response), and the Weber and Rinne tuning fork tests. In bilateral SNHL, the Weber test lateralizes to the better ear.

Conductive hearing loss occurs when sound cannot efficiently travel through the outer or middle ear to reach the inner ear. In a healthy ear, sound waves move through an intricate mechanical chain: the eardrum vibrates, setting three tiny ossicle bones in motion, which then transmit vibration to the cochlea. When any part of this chain is disrupted, hearing is reduced.

People with conductive hearing loss often describe sounds as "muffled," like hearing through cotton wool or wearing earplugs. Unlike sensorineural loss, the quality of what is heard is reduced but not typically distorted — sounds are simply perceived as softer across both high and low tones.

• Earwax (cerumen) buildup — the most common
• Middle ear infection with fluid (otitis media)
• Otosclerosis (abnormal bone growth)
• Cholesteatoma (skin cyst in middle ear)
• Perforated eardrum
• Otitis externa (swimmer's ear)
• Foreign object in ear canal
• Fractured petrous bone after trauma

• "Muffled" or dampened sound quality
• Hearing better in one ear than the other
• Feeling of fullness or pressure in the ear
• Soft or faint perception of own voice
• Ear pain (in infection-related cases)
• Drainage or discharge (in some cases)

An ENT specialist uses several complementary tests. Otoscopy visually inspects the ear canal and eardrum for obstructions or damage. A tympanogram measures eardrum mobility — if middle ear pressure differs from the outer ear, the eardrum won't oscillate normally, pointing to fluid, infection, or structural issues.

The Rinne test (tuning fork at mastoid bone vs. ear canal) and the Weber test (tuning fork at crown of head) together distinguish conductive from sensorineural loss. In conductive hearing loss, the Weber test lateralizes to the impaired ear, and bone conduction is heard longer than air conduction — the opposite of normal.

Pure-tone audiometry reveals an "air-bone gap" in conductive loss: bone conduction thresholds are normal, but air conduction thresholds are elevated, showing exactly how much the mechanical pathway is impaired.

Seek care within 24 hours!

Sudden hearing loss is a medical emergency. Treatment with corticosteroids is most effective when started within the first 24–48 hours. Delays dramatically reduce the chance of recovery. See an ENT doctor immediately, do not wait to see if it improves on its own.

Sudden sensorineural hearing loss (SSNHL) — colloquially called "sudden hearing loss" — is defined as a loss of 30 dB or more in at least three frequencies, occurring within 72 hours. It usually affects one ear and may be accompanied by tinnitus, a sensation of ear fullness, or dizziness.

Approximately 66,000 new cases are diagnosed annually in the United States (roughly 27 per 100,000 people), according to the AAO-HNS Clinical Practice Guideline and multiple peer-reviewed studies. In over 90% of cases, the underlying cause remains unknown (termed idiopathic SSNHL), though reduced blood flow to the cochlea is widely considered a key mechanism.

• Reduced cochlear blood circulation (most common theory)
• Viral infections (herpes, chickenpox reactivation)
• Stress and circulatory disorders
• Autoimmune disease
• Arteriosclerosis or blood clots
• Cervical spine injury (e.g. whiplash)
• Ruptured oval or round window membrane
• Metabolic disorders (diabetes, high cholesterol)

• Hearing loss in one ear with no apparent cause
• No earache (distinguishes it from infection)
• Tinnitus (ringing or buzzing)
• Ear fullness or pressure
• Dizziness or vertigo
• Loss of sensation in the outer ear

Idiopathic sudden hearing loss accounts for most cases — no organic cause can be found despite thorough examination. This is the most studied subtype and the focus of most clinical research. Stress-related sudden hearing loss is increasingly recognized as a distinct trigger: extreme stress can cause circulatory disruption to the cochlea. Stress reduction is therefore a formal part of treatment.

Diagnosis relies on ruling out other causes. An ENT specialist will conduct blood pressure measurement, blood tests, ear microscopy, otoscopy, and in some cases MRI (to exclude acoustic neuroma). Pure-tone audiometry confirms the degree and pattern of loss. Brainstem electrical response audiometry (BERA) and otoacoustic emission (OAE) measurement are used to exclude auditory nerve pathology.

The primary treatment is corticosteroids (oral or intratympanic injection), ideally administered within 24–48 hours of onset. These reduce cochlear inflammation and edema. Additional treatments may include:

• Corticosteroids: First-line treatment. Oral prednisone or direct injection into the middle ear. Most effective early.
• Circulation Medication: Rheological drugs and local anesthetics (procaine, lidocaine) to improve inner ear blood flow.
• Stress Reduction: Lifestyle changes, exercise, and stress management are formally recommended alongside medication.
• Hearing Aids: When hearing loss becomes chronic, hearing aids — including those with tinnitus masking — are the primary solution.

Mixed hearing loss is, as the name suggests, a simultaneous combination of sensorineural and conductive hearing loss in the same ear. This means there is both inner ear (or nerve) damage and a mechanical problem in the outer or middle ear at the same time.

Mixed hearing loss is more complex to treat than either type alone. It typically requires addressing the conductive component first (via medication or surgery where possible), followed by hearing aids to manage the sensorineural component that remains. Audiometry shows both an air-bone gap (indicating the conductive component) and elevated bone conduction thresholds (indicating the sensorineural component).