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This is a clinician-written, evidence-based summary aligned to the USMLE Step 2 CK Content Outline. It is intended for medical students preparing for USMLE Step 2 CK. Management reflects current ACC/AHA, USPSTF, and APA guidelines. Always cross-reference with UpToDate, institutional protocols, and clinical judgment.
The Bottom Line
- Conductive hearing loss = outer/middle ear problem; sensorineural hearing loss = cochlea, CN VIII, or central auditory pathway
- Weber lateralizes to the affected ear in conductive loss and to the unaffected ear in sensorineural loss
- Rinne is abnormal in conductive loss: bone conduction greater than air conduction; normal or positive Rinne in sensorineural loss
- Sudden sensorineural hearing loss is an otologic emergency; treat urgently with corticosteroids and ENT/audiology evaluation
- Unilateral/asymmetric sensorineural loss or tinnitus requires evaluation for vestibular schwannoma
Overview
Hearing loss is classified as conductive, sensorineural, or mixed. Conductive hearing loss results from impaired transmission of sound through the external canal, tympanic membrane, or ossicles. Sensorineural hearing loss results from cochlear hair cell injury, auditory nerve pathology, or central pathway disease. Step 2 CK commonly tests bedside tuning fork patterns, presbycusis, cerumen impaction, otitis media with effusion, otosclerosis, noise-induced hearing loss, and sudden sensorineural hearing loss.
Epidemiology
Hearing loss is common and increases with age. Presbycusis is the most common adult cause of bilateral sensorineural hearing loss and affects high frequencies first. Conductive causes include cerumen impaction, otitis externa, otitis media with effusion, TM perforation, cholesteatoma, and otosclerosis. Sensorineural causes include aging, noise exposure, ototoxic drugs, Meniere disease, labyrinthitis, vestibular schwannoma, autoimmune inner-ear disease, and idiopathic sudden sensorineural hearing loss.
Clinical Features
Symptoms
Muffled hearing, difficulty hearing speech, or needing increased volume
Conductive loss: ear fullness, autophony, history of infection, cerumen, otorrhea, or TM abnormality
Sensorineural loss: difficulty understanding speech, tinnitus, noise exposure, ototoxic medication, or age-related progression
Sudden unilateral hearing loss within <=72 h is an emergency
Unilateral tinnitus, asymmetric hearing loss, or imbalance suggests vestibular schwannoma
Vertigo plus hearing loss suggests labyrinthitis, Meniere disease, or posterior circulation stroke
Signs
Cerumen impaction, canal edema, TM perforation, retraction, or middle-ear effusion suggests conductive loss
Normal otoscopy does not exclude sensorineural loss
Weber to affected ear + Rinne BC>AC = conductive loss
Weber to unaffected ear + Rinne AC>BC bilaterally = sensorineural loss
Neurologic deficits or cerebellar signs suggest central pathology
Investigations
First-line
OtoscopyLook for cerumen, otitis externa, TM perforation, cholesteatoma, effusion, or mass
Weber and Rinne tuning fork testsRapid bedside classification; use 512-Hz fork
AudiometryConfirms type, severity, symmetry, and frequencies affected; pure tone and speech discrimination are core tests
Second-line
TympanometryAssesses middle-ear pressure and TM mobility; useful for effusion, eustachian tube dysfunction, and ossicular problems
Medication and exposure reviewAminoglycosides, cisplatin, loop diuretics, salicylates, noise, barotrauma, trauma
Specialist
MRI internal auditory canals/brainUnilateral/asymmetric SNHL, unilateral tinnitus, poor speech discrimination, or vestibular schwannoma concern
Urgent audiology/ENTSudden sensorineural hearing loss should be confirmed and treated promptly; do not wait weeks
CT temporal boneConductive loss with suspected ossicular erosion, cholesteatoma, temporal bone trauma, or congenital anomaly
1
Conductive hearing loss
- Cerumen impaction: cerumenolytics, irrigation if TM intact, or manual removal
- Otitis externa: topical antibiotic drops and canal care
- Otitis media with effusion: observation initially; audiology/ENT if persistent >=3 months or language/hearing concerns
- Otosclerosis: hearing aids or stapedotomy depending on severity and patient preference
- Cholesteatoma: ENT surgical management
2
Sensorineural hearing loss
- Presbycusis/noise-induced loss: hearing aids, assistive devices, noise protection, communication strategies
- Stop or avoid ototoxic medications when possible and monitor hearing
- Cochlear implant evaluation for severe-to-profound SNHL with poor hearing-aid benefit
3
Sudden sensorineural hearing loss
- Differentiate from conductive loss immediately with otoscopy and tuning fork tests
- Audiometry as soon as possible, ideally within 14 days
- Offer systemic corticosteroids within 2 weeks of onset unless contraindicated
- Intratympanic steroid therapy may be offered as salvage 2-6 weeks after onset or when systemic steroids contraindicated
- Evaluate for retrocochlear pathology with MRI or auditory brainstem response
Complications
- Language delay: Pediatric hearing loss can impair speech and educational development
- Falls and cognitive burden: Adult hearing loss is associated with social isolation, falls, and cognitive strain
- Permanent hearing loss: Delay in sudden sensorineural hearing loss treatment worsens prognosis
- Cholesteatoma complications: Ossicular erosion, facial nerve palsy, labyrinthine fistula, intracranial spread
- Vestibular schwannoma: Progressive unilateral SNHL/tinnitus with imbalance
USMLE Step 2 CK Exam Tips
- 1Weber lateralizes to the bad ear in conductive hearing loss; to the good ear in sensorineural loss
- 2Rinne: normal is air conduction > bone conduction. Bone > air = conductive loss
- 3Presbycusis = bilateral high-frequency sensorineural hearing loss in older adults
- 4Sudden unilateral SNHL is an emergency — steroids + urgent ENT/audiology
- 5Do not attribute sudden hearing loss to eustachian tube dysfunction without tuning fork/audiometry assessment
- 6Unilateral tinnitus/asymmetric SNHL = MRI for vestibular schwannoma
- 7Cholesteatoma = pearly retraction pocket/keratin debris + conductive loss — surgical disease
practicetest your knowledge on hearing loss (conductive vs sensorineural)Apply what you've learnt with USMLE Step 2 CK-style questions from the iatroX Q-Bank — ent and beyond.
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