Hearing for the clinic: conductive and sensorineural loss
- Applied anatomy
Hearing loss is conductive when sound cannot reach the inner ear and sensorineural when the cochlea or nerve is damaged.
What it is
Every hearing complaint starts with one question: where is the block? Conductive loss arises in the ear canal, drum or ossicles (wax, effusion, perforation, otosclerosis); sensorineural loss arises in the cochlea or the auditory nerve (age, noise, ototoxic drugs, sudden idiopathic loss, tumours of the nerve). Tuning forks separate the two at the bedside and the audiogram confirms it. The distinction drives the next step: many conductive losses are treatable, and a sudden sensorineural loss is an emergency.
Applied anatomy
- Conductive pathway: auricle, ear canal, tympanic membrane, ossicles, oval window.
- Sensorineural pathway: cochlea (hair cells), spiral ganglion and cochlear nerve, brainstem nuclei, auditory cortex.
- Mixed loss: both components, for example chronic otitis media that has also damaged the cochlea.
Clinical physiology
- The middle ear matches sound in air to fluid in the cochlea; losing it (perforation, fluid, ossicular fixation) lowers air conduction while bone conduction stays normal.
- In sensorineural loss air and bone conduction fall together, so the Rinne stays positive.
Conductive vs sensorineural loss at the bedside
| Feature | Conductive | Sensorineural |
|---|---|---|
| Site | Canal, drum, ossicles | Cochlea, auditory nerve |
| Rinne in the affected ear | Negative (bone > air) | Positive (air > bone) |
| Weber | To the affected ear | To the better ear |
| Audiogram | Air-bone gap | Air and bone thresholds both reduced, no gap |
| Typical causes | Wax, effusion, perforation, otosclerosis, cholesteatoma | Age, noise, ototoxic drugs, sudden idiopathic loss, Ménière, vestibular schwannoma |
Clinical correlation
- Wax and otitis media with effusion are the most common treatable causes of conductive loss in primary care.
- Age-related loss is bilateral and starts in the high frequencies; patients hear but do not understand speech in noise.
- Asymmetric or unilateral sensorineural loss needs imaging of the internal auditory canal.
- In children, any hearing loss threatens language development: listen to the parents and test early.
Next step / Initial management
- Otoscopy first (wax, effusion, perforation), then Rinne and Weber, then pure-tone audiometry with tympanometry.
- Treatable conductive causes: remove wax, follow effusion, treat infection; offer hearing aids when loss persists.
- Sudden sensorineural loss: same-day referral to ENT for audiometry; corticosteroids work best when started early.
- Refer routinely to ENT: unexplained conductive loss with a normal drum, asymmetric loss, unilateral tinnitus, and any child with suspected hearing loss.
- Occupational noise or ototoxic drug exposure: periodic audiometry and hearing protection.
Test yourself
Think of the answer, then tap the question to see it.
Left ear: Rinne negative; Weber lateralises to the left. What type of loss is this?
Left conductive hearing loss: bone conduction beats air conduction in that ear and the Weber goes to the affected side.
A 30-year-old woman has slowly progressive conductive loss with a normal drum and a mother with the same problem. What is the likely cause?
Otosclerosis: abnormal bone fixes the stapes footplate in the oval window. Audiometry may show a Carhart notch near 2 kHz on bone conduction.
A man wakes with hearing loss in one ear and a normal ear exam. What is the next step?
Treat it as sudden sensorineural hearing loss: same-day ENT referral for audiometry and early corticosteroids, then a search for a cause such as MRI.
Elsewhere in DurgiPedia
Connections
Educational content; it does not replace a medical assessment and is not a clinical instruction. For a real case, follow current guidelines and specialist advice.
Sources: How Do We Hear? (National Institute on Deafness and Other Communication Disorders (NIDCD), NIH, 2022); Deafness and hearing loss (fact sheet) (World Health Organization, 2026); Sudden Deafness (National Institute on Deafness and Other Communication Disorders (NIDCD), NIH, 2018); Primary ear and hearing care: training manual (World Health Organization, 2023).
Spotted a mistake?We are always improving for the community. Tell us what is wrong and our team will review it.Report a mistake
Representative model, for educational purposes only.