Conductive hearing loss

Conductive hearing loss is a failure in the efficient conduction of sound waves through the outer ear, tympanic membrane (eardrum) or middle ears (ossicles). This type of hearing loss may occur in conjunction with sensorineural hearing loss or alone.

Common

 * Cerumen (earwax)
 * Otitis externa

Uncommon

 * Foreign body in the external auditory canal
 * Exostoses
 * Tumour of the of canal
 * Congenital atresia

Common

 * Acute otitis media
 * Serous otitis media
 * Tympanic membrane perforation

Uncommon

 * Cholesteatoma
 * Otosclerosis
 * Middle ear tumour
 * Temporal bone trauma

Differentiating conductive and sensorineuronal hearing loss
When a Weber test is carried out, sound localizes to the ear affected by the conductive loss. A Rinne test, in which air conduction is normally greater than bone conduction, is usually negative (abnormal), and shows higher greater bone conduction than air conduction.

Table 1. A table comparing sensorineural hearing loss to conductive