Hearing Loss & Tinnitus
A board-focused walkthrough of hearing loss and tinnitus that splits every case into conductive vs sensorineural, drills the Weber/Rinne pattern and classic etiology buzzwords, and pins down the next-best-step for the emergencies — sudden SNHL and unilateral/asymmetric loss suggesting vestibular schwannoma.
Hearing loss is the boards' favorite ENT topic because a bedside tuning-fork exam plus the history usually nails the diagnosis before any imaging. Every case first splits into conductive (a mechanical block anywhere from the ear canal through the ossicles) versus sensorineural (a lesion in the cochlea, cranial nerve VIII, or central pathways). Conductive losses are structural and often correctable — cerumen, effusion, perforation, otosclerosis, cholesteatoma. Sensorineural losses are cochlear or retrocochlear — presbycusis, noise, ototoxins, Ménière disease, and vestibular schwannoma. Tinnitus (phantom ringing) usually rides along with sensorineural loss; the exception the boards want you to catch is pulsatile tinnitus, which is vascular until proven otherwise. Master three things and most vignettes fall: the Weber/Rinne pattern, the classic buzzword for each etiology, and the single next-best-step for the two emergencies — sudden sensorineural loss and unilateral/asymmetric loss suggesting a tumor.
Tuning-fork localization: Weber & Rinne
| Test | Technique | Normal | Conductive loss | Sensorineural loss |
|---|---|---|---|---|
| Rinne | Fork on mastoid, then beside ear canal | AC > BC (both ears) | BC > AC in affected ear (Rinne "negative") | AC > BC preserved (both reduced) |
| Weber | Fork midline on forehead/vertex | No lateralization | Lateralizes to the affected (worse) ear | Lateralizes away, to the good ear |
Conductive causes
- Cerumen impaction / otitis media / effusion / TM perforation — most common, structural
- Otosclerosis — young adult, progressive CHL, +family history, normal TM, Carhart notch (~2 kHz); treat with hearing aid or stapedectomy
- Cholesteatoma — painless foul otorrhea + pearly retraction-pocket mass eroding ossicles; needs CT + surgery
Sensorineural causes
- Presbycusis — most common; symmetric high-frequency loss, poor speech discrimination in noise
- Noise-induced — 4000 Hz notch on audiogram
- Congenital — CMV = #1 non-genetic cause; connexin-26 (GJB2) = #1 genetic
- Ménière, vestibular schwannoma, ototoxicity
Ototoxic drugs — aminoglycosides, cisplatin, loop diuretics, salicylates/aspirin (dose-related, reversible tinnitus), quinine
Red flags
- Pulsatile tinnitus → vascular workup (glomus tumor/paraganglioma behind TM, dural AV fistula, carotid disease, idiopathic intracranial hypertension)
- Unilateral/asymmetric SNHL → image the internal auditory canal (rule out schwannoma)
A 45-year-old reports 8 months of progressive hearing loss and ringing in the right ear with occasional imbalance; speech discrimination is disproportionately poor and Weber lateralizes to the left (good) ear.
Diagnosis: vestibular schwannoma (acoustic neuroma) at the cerebellopontine angle — a Schwann-cell tumor of the vestibular division of CN VIII (hence the name), S-100 positive. Large tumors compress CN V (loss of corneal reflex, facial numbness) and CN VII. Bilateral schwannomas = neurofibromatosis type 2.
Next best step: audiometry documents the asymmetric SNHL, then MRI of the internal auditory canals with gadolinium (the diagnostic test). Manage by observation, stereotactic radiosurgery, or microsurgical resection depending on size and symptoms.
A 52-year-old wakes with hearing loss in one ear over a few hours plus tinnitus and aural fullness; the ear canal and otoscopy are normal, and Weber lateralizes to the opposite ear (confirming sensorineural).
Diagnosis: idiopathic sudden sensorineural hearing loss (SSNHL) — an otologic emergency defined as ≥30 dB loss across 3 contiguous frequencies within 72 hours.
Next best step: audiometry to confirm, then start oral corticosteroids promptly (intratympanic steroids are an option); obtain MRI to exclude a retrocochlear lesion. Do not wait — the treatment window is short. Contrast: normal otoscopy excludes cerumen/effusion, which would be conductive, not this.
A 40-year-old has recurrent spontaneous vertigo lasting 20 minutes to several hours, with fluctuating low-frequency hearing loss, tinnitus, and a sensation of ear fullness; she is well between attacks.
Diagnosis: Ménière disease — endolymphatic hydrops. The classic tetrad is vertigo + fluctuating SNHL + tinnitus + aural fullness.
Management: lifestyle first — low-sodium diet plus a diuretic (e.g., thiazide), caffeine/alcohol reduction; acute attacks get vestibular suppressants (meclizine) and antiemetics. Refractory disease: intratympanic gentamicin (chemical ablation) or endolymphatic sac surgery.
Key contrasts: attacks lasting seconds with positional trigger (Dix-Hallpike) = BPPV; continuous days-long vertigo after a viral illness with hearing loss = labyrinthitis (vs vestibular neuritis, which spares hearing).
"Weber to the Worse ear = conductive" (both start with W). In sensorineural loss it swings the other way — to the better/normal ear.
Rinne: normal and sensorineural both keep Air > Bone ("positive" Rinne); only conductive loss flips to Bone > Air.
Sanity check with your own ears: plug one ear and hum — your voice booms louder on the plugged side (the occlusion effect). A conductive block does the same thing, so Weber lateralizes toward the affected ear.
Comparing sensorineural causes
| Cause | Classic vignette | Audiogram / finding | Key step |
|---|---|---|---|
| Presbycusis | Elderly, worse in noisy rooms | Symmetric high-frequency SNHL | Hearing aids |
| Noise-induced | Chronic loud exposure (factory, firearms) | 4000 Hz notch | Ear protection |
| Ménière | Episodic vertigo + fullness + tinnitus | Fluctuating low-frequency SNHL | Low salt + diuretic |
| Vestibular schwannoma | Unilateral loss + tinnitus + imbalance | Asymmetric SNHL, poor discrimination | MRI IAC + gadolinium |
| Ototoxicity | Aminoglycoside / cisplatin / aspirin | Bilateral high-frequency ± tinnitus | Stop the drug |
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