Hearing Loss

Adult hearing loss is usually sensorineural: the hair cells of the cochlea, which do not regenerate in humans, are progressively lost through ageing and cumulative noise exposure. High frequencies go first, which is why the earliest complaint is rarely volume — it is clarity. Speech sounds mumbled, consonants blur, and understanding collapses in restaurants and group conversation while a one-to-one chat in a quiet room still feels fine. Conductive loss is a different mechanism, where sound cannot reach the cochlea because of wax impaction, middle-ear fluid or otosclerosis, and much of it is treatable. The distinction matters, so audiometry with bone conduction is the essential test rather than a phone app. Two things deserve emphasis. First, sudden sensorineural hearing loss in one ear is a medical emergency: steroid treatment within 72 hours substantially improves recovery odds, and delay costs hearing permanently. Second, the Lancet Commission identifies untreated mid-life hearing loss as the single largest modifiable risk factor for dementia, plausibly through cognitive load and social withdrawal, and hearing aid use is associated with slower cognitive decline in at-risk groups. People wait an average of seven to ten years before seeking help, which is a large avoidable cost.

• •Speech sounds mumbled, especially consonants
• •Difficulty following conversation in background noise
• •Turning the television up beyond what others prefer
• •Ringing or hissing tinnitus
• •Fatigue after social events from listening effort
• •Asking for repetition frequently

• •Noise exposure, occupational or recreational
• •Age-related presbycusis
• •Ototoxic medications
• •Earwax impaction or middle-ear fluid
• •Otosclerosis
• •Diabetes, smoking and vascular disease

Cumulative noise exposure damaging cochlear hair cells, age-related presbycusis, ototoxic drugs including aminoglycosides, cisplatin and high-dose loop diuretics, genetic predisposition, chronic middle-ear disease, and vascular risk factors such as diabetes and smoking.