Low Frequency Hearing Loss Causes and Evaluation

Primary Causes

• Ménière's disease is the classic cause of low frequency hearing loss, presenting with an isolated low-frequency hearing trough on audiometry, characterized by fluctuating hearing loss that may affect one or both sides, with episodes of vertigo 1, 2, 3
• Autoimmune inner ear disease presents with fluctuating bilateral hearing loss that may preferentially affect low frequencies, often accompanied by vertigo in some cases 1, 2, 4
• Conductive pathology, such as cerumen impaction or middle ear fluid, can mimic low frequency hearing loss and must be excluded through otoscopy and tuning fork testing 3, 5

Secondary and Systemic Causes

• Syphilis can cause bilateral fluctuating hearing loss with low frequency involvement 1, 2
• Lyme disease presents with fluctuating bilateral audiovestibular symptoms 1, 2
• Meningitis may cause bilateral hearing loss 1, 2
• MELAS can present with hearing loss affecting various frequencies 1, 2
• Genetic disorders may be syndromic or nonsyndromic, with variable audiometric patterns 1, 2, 6
• Ototoxic medications, such as aminoglycosides and cisplatin, can cause sensorineural hearing loss that may initially affect lower frequencies 1, 2

Clinical Evaluation Approach

• Antecedent fluctuating hearing loss on one or both sides strongly suggests Ménière's disease or autoimmune causes 1, 2, 3
• Recent viral illness, bacterial meningitis, or exposure to ototoxic medications should be considered in the patient's history 7
• Otoscopy is essential to exclude conductive causes such as cerumen impaction or middle ear fluid 3
• Perform Weber and Rinne tuning fork tests to differentiate conductive from sensorineural loss 3, 5

Common Pitfalls

• Failing to remove cerumen before establishing diagnosis can lead to misdiagnosis of sensorineural loss when conductive loss is present 3
• Assuming all low frequency loss is Ménière's disease without considering autoimmune, infectious, or ototoxic causes 1, 2
• Missing bilateral presentation, which should prompt evaluation for systemic causes including autoimmune disease, infection, or ototoxicity 1, 2