Otorhinolaryngology (ENT)
Hearing Loss and Deafness
Hearing loss for MBBS ENT: conductive versus sensorineural, presbycusis, noise and ototoxic damage, sudden and congenital deafness, hearing aids and cochlear implants, NMC codes EN4.
MedNext Academy | 3 min read
Hearing Loss and Deafness
Hearing loss for MBBS ENT: conductive versus sensorineural, presbycusis, noise and ototoxic damage, sudden and congenital deafness, hearing aids and cochlear implants, NMC codes EN4.
This chapter organises the causes of hearing loss and their management. It distinguishes conductive from sensorineural loss, covers presbycusis, noise and ototoxic damage, sudden and congenital deafness, and sets out rehabilitation from hearing aids to cochlear implants, with emphasis on early detection in children.
High-yield: Hearing Loss and Deafness
- Hearing loss is broadly conductive, sensorineural or mixed; the tuning fork tests and audiogram separate the first two.
- Conductive loss arises from the external or middle ear, for example wax, perforation, effusion or otosclerosis.
- Sensorineural loss arises from the cochlea or auditory nerve, for example presbycusis, noise damage, ototoxic drugs or Meniere disease.
- Presbycusis is age-related sensorineural loss that affects high frequencies first and impairs speech discrimination.
- Noise-induced hearing loss classically produces a notch at 4 kilohertz and is preventable with ear protection.
- Aminoglycosides, cisplatin, loop diuretics and high-dose aspirin are important ototoxic agents.
- Sudden sensorineural hearing loss is an emergency and is treated with corticosteroids after excluding other causes.
- Congenital hearing loss may be genetic or acquired; the TORCH infections, especially rubella and cytomegalovirus, are important prenatal causes.
- Universal newborn hearing screening allows early detection and rehabilitation, ideally in the first months of life.
- Hearing aids amplify sound for most sensorineural and some conductive losses that are not surgically correctable.
- Cochlear implants bypass damaged hair cells and directly stimulate the auditory nerve in severe to profound sensorineural loss.
- Early intervention in childhood deafness is critical because it affects speech and language development.
- A retrocochlear lesion such as an acoustic neuroma should be considered in asymmetrical sensorineural loss with poor speech discrimination.
- Wax impaction is a common and easily reversible cause of conductive hearing loss.
Conductive versus sensorineural loss
- **Conductive:** External or middle ear. Wax, perforation, effusion, otosclerosis. Air-bone gap on audiogram.
- **Sensorineural:** Cochlea or nerve. Presbycusis, noise, ototoxic drugs, Meniere. No air-bone gap.
- **Ototoxic drugs:** Aminoglycosides, cisplatin, loop diuretics, high-dose aspirin.
- **Rehabilitation:** Hearing aid for most losses; cochlear implant for severe to profound sensorineural loss.
NMC competencies in this chapter
- **EN4.12:** Types and causes of hearing loss
- **EN4.13:** Conductive hearing loss: causes and management
- **EN4.14:** Sensorineural hearing loss: causes and management
- **EN4.15:** Presbycusis, noise-induced and ototoxic hearing loss
- **EN4.16:** Newborn hearing screening and early identification of deafness
- **EN4.17:** Rehabilitation: hearing aids and cochlear implants
- **EN4.18:** Sudden sensorineural hearing loss and its management
Frequently Asked Questions
What is the difference between conductive and sensorineural hearing loss?
Conductive loss comes from the external or middle ear and shows an air-bone gap on the audiogram. Sensorineural loss comes from the cochlea or auditory nerve and shows no air-bone gap.
Which drugs damage hearing?
Aminoglycoside antibiotics, cisplatin, loop diuretics and high-dose aspirin are the classic ototoxic agents, and hearing should be monitored when they are used.
Why is sudden hearing loss an emergency?
Sudden sensorineural hearing loss can be permanent if untreated. Prompt corticosteroids give the best chance of recovery, so it needs urgent assessment.
When is a cochlear implant used instead of a hearing aid?
A cochlear implant is used for severe to profound sensorineural loss that a hearing aid cannot help, because it bypasses damaged hair cells and stimulates the auditory nerve directly.
Continue reading
MBBSAll Otorhinolaryngology (ENT) chapters
Continue through the Otorhinolaryngology (ENT) chapter map.
Continue studying Otorhinolaryngology (ENT)
Explore clinician-written learning resources, structured revision and practice across the MedNext platform.
Open in the MedNext appSee plans

