Hearing Loss (SNHL / CHL) and Tinnitus

Differential Diagnoses

Sensorineural Hearing Loss (SNHL)

• Presbycusis (often bilateral, high-frequency loss)

• Noise-induced hearing loss (occupational or recreational exposure)

• Ototoxic medications (aminoglycosides, loop diuretics, chemotherapy agents)

• Idiopathic sudden sensorineural hearing loss (urgent ENT referral if within 72 hours)

• Hereditary SNHL (family history)

• Cerebrovascular ischaemia (e.g. anterior inferior cerebellar artery involvement)

• Barotrauma or head trauma (may also cause conductive component)

• Ménière’s disease (episodic vertigo, tinnitus, fluctuating hearing loss)

• Acoustic neuroma (vestibular schwannoma, often unilateral tinnitus/HL)

Conductive Hearing Loss (CHL)

• Outer Ear

  • Cerumen impaction (common, easily treated)

  • Exostosis (surfer’s ear)

  • Squamous cell carcinoma (rare)

• Middle Ear

  • Eustachian tube dysfunction (URTI, sinusitis, allergies)

  • Otitis media (serous, acute, or chronic suppurative)

  • Otosclerosis (bony overgrowth at stapes footplate, classically bilateral)

  • Cholesteatoma (erosive growth, can be mixed CHL/SNHL)

  • Head trauma causing ossicular disruption

  • Tympanic membrane perforation

Tinnitus

• Primary (Idiopathic)

  • May or may not have SNHL, but typically not CHL

  • Often bilateral, high-pitched

• Secondary

  • Can co-exist with CHL or SNHL

  • Caused by underlying conditions (otosclerosis, Ménière’s, cholesteatoma, head trauma)

  • Pulsatile tinnitus suggests possible vascular lesion (glomus tumour, arteriovenous malformation)

• When to Image

  • Pulsatile tinnitus

  • Unilateral hearing loss or unilateral tinnitus

  • Suspected middle ear pathology (otosclerosis, cholesteatoma)

  • Significant head trauma

History

• Onset (acute vs gradual), unilateral or bilateral

• Noise exposure (occupational or recreational)

• Family history of early hearing loss

• Medications (e.g. aminoglycosides, diuretics, chemotherapy agents, salicylates)

• Trauma (head or barotrauma)

• Associated Symptoms

  • Otalgia, otorrhoea (infection or trauma)

  • Vertigo or imbalance (Ménière’s, labyrinthitis, vestibular schwannoma)

  • Aural fullness or pressure

  • Facial numbness or hemiparesis (suspect acoustic neuroma or intracranial lesion)

Examination

• Otoscopy (look for cerumen impaction, exostoses, perforation, cholesteatoma)

• Pneumatic Otoscopy (assesses TM mobility if effusion suspected)

• Tuning Fork Tests

  • Rinne (AC > BC is normal or SNHL, BC > AC is CHL in that ear)

  • Weber (lateralises to the affected ear in CHL and to the better ear in SNHL)

• Cranial Nerves (especially CN VII and CN VIII)

• Audiometry (confirm type and degree of hearing loss, including speech discrimination)

Investigations

• Formal Audiological Assessment

  • Pure tone audiometry and speech audiometry

  • Tympanometry (middle ear pressure and compliance)

• Imaging

  • CT temporal bone (otosclerosis, cholesteatoma, trauma)

  • MRI internal acoustic meatus if acoustic neuroma suspected or unexplained unilateral SNHL/tinnitus

• Laboratory Tests if systemic causes suspected (e.g. autoimmune markers, syphilis serology, etc)

Tinnitus Management

• Evaluate for Anxiety or Depression (common comorbidities)

• Address Underlying Cause

  • Remove cerumen, treat otitis media, manage Ménière’s, or review medication list

• Audiology Referral

  • Hearing aids if coexistent hearing loss

  • Sound therapy or masking devices (white noise machines, hearing aid noise generators)

• Counselling and Psychological Support

  • Cognitive behavioural therapy (CBT) can reduce distress

• Lifestyle Modifications

  • Limit caffeine, alcohol, nicotine

  • Avoid loud environments or use ear protection

• Other Interventions

  • Relaxation techniques, mindfulness, stress management

Notes:

• Presbycusis and noise-induced SNHL are the most common adult SNHL causes

• Cerumen impaction is a frequent reversible cause of CHL

• Sudden SNHL is an ENT emergency (initiate high-dose corticosteroids if no contraindication)

• Pulsatile tinnitus or unilateral tinnitus/hearing loss warrants imaging to exclude vascular or retrocochlear lesion

• Tinnitus management focuses on education, addressing treatable causes, and minimising the impact on quality of life through sound therapy and psychological support

• Hearing aid fitting can alleviate tinnitus by improving external sound perception