Any disease process which interferes with the conduction
of sound t0 reach the cochlea causes conductive hearing loss.
loss. The lesion may lie in the external ear and tympanic
membrane, middle ear or ossisicles up to stapediovestibular joint.
The characteristics of conductive hearing loss are:
1. Negative Rinne test i.e. BC> AC.
2. Weber lateralized to poorer ear.
3. Normal absolute bone conduction.
4. Low frequencies affected more.
5. Audiometry shows bone conduction better than air
conduction with air-bone gap. Greater the air-bone
gap, more is the conductive loss
6. Loss is not more than 60 dB.
7. Speech discrimination is good.
- Meatal atresia
- Fixation of stapes footplate
- Fixation of malleus head
- Ossicular discontinuity
- Congenital cholesteatoma
External Ear: Any obstruction in the ear canal eg., wax, foreign body, furuncle, acute inflammatory swelling, benign or malignant tumour or atresia of the ear canal.
- Perforation of tympanic membrane: traumatic or infective
- Fluid in the middle ear eg., ASOM, serous otitis media or haemotympanum
- Mass in the middle ear eg., benign or malignant tumour
- Disruption of ossicles eg., trauma to ossicles, CSOM, cholesteatoma
- Fixation of ossicles eg., otosclerosis, tympanosclerosis, adhesive otitis media
- Eustachian tube blockage eg., retracted tympanic membrane, serous otitis media
Most cases of conductive hearing loss can be managed by
medical or surgical means. It consists of:
1. Removal of canal obstructions, e.g. Impacted wax,
foreign body, osteoma or exostosis, keratotic mass,
benign or malignant tumours, meatal atresia.
2. Removal of fluid. Myringotomy with or without
3. Removal of mass from middle ear. Tympanotomy
and removal of small middle ear tumours or
cholesteatoma behind an intact drum.
4. Stapedectomy, as in otosclerotic fixation of stapes
S. Tympanoplasty. Repair of perforation , ossicular
chain or both.
6. Hearing aid. In cases where surgery is not possible,
refused or has failed.