Hearing Loss Diagnosis and Management

Anatomical Differences

Conductive hearing loss occurs when sound cannot properly travel through the external ear canal to the eardrum and the tiny bones (ossicles) of the middle ear, affecting structures that "conduct" sound waves to the cochlea 1
Sensorineural hearing loss involves damage to the inner ear (cochlea) or the nerve pathways from the inner ear to the brain, sometimes referred to colloquially as "nerve hearing loss" 3
Mixed hearing loss is a combination of both conductive and sensorineural components occurring in the same ear 1

Otoscopic examination is crucial - patients with SNHL will almost always have a normal otoscopic examination, whereas examination of patients with CHL will often show abnormalities 1
Weber and Rinne tuning fork tests are traditional methods to differentiate between CHL and SNHL 1
In Weber test, sound lateralizes to the ear with CHL or away from the ear with SNHL 1
In Rinne test, air conduction is normally better than bone conduction; if bone conduction is better, CHL is present 1

Patients cannot accurately distinguish subjective hearing loss as either CHL or SNHL based on symptoms alone 1
Patients with SSNHL often report tinnitus, ear fullness or pressure, and vertigo, though these symptoms may also be present in CHL 1
CHL may present with identifiable causes such as cerumen impaction, middle ear fluid, otitis media, foreign bodies, perforated tympanic membrane, canal edema from otitis externa, otosclerosis, trauma, or cholesteatoma 1

CHL and SNHL have markedly different management strategies, making proper differentiation essential 1, 2
Many causes of CHL can be treated effectively, such as removal of cerumen impaction, which can be potentially curative 1
SNHL is usually permanent and treatment focuses on audiologic rehabilitation and hearing amplification 3

Beyond communication difficulties, untreated hearing loss is associated with increased risk of dementia, depression, cardiovascular disease, and falls 6

Understanding these differences is crucial for proper diagnosis and management, as misdiagnosis may result in delayed or inappropriate treatment, potentially leading to permanent hearing loss and reduced quality of life 1