Hearing Problems
Conductive Hearing Loss
If there is a problem in the outer or middle part of the ears, this affects the way sound is carried, or conducted, through to the inner ear and the rest of the auditory system.
Hearing loss that results from damage to or disorders of the outer and middle ear is therefore referred to as conductive hearing loss. Causes of conductive hearing loss that arise from the outer ear include:
- stenosis (narrowing of the ear canal)
- wax impaction
- exostoses (bony growths in the ear canal) when they are large enough to completely block the canal
- otitis externa (swimmer's or tropical ear) when it causes sufficient swelling to block the ear canal
Causes of conductive hearing loss that arise from the middle ear include:
- perforation of the tympanic membrane (eardrum), which may result from trauma, ear infections, or rapid changes in air pressure
- tympanosclerosis (thickening of the tympanic membrane)
- otitis media (a buildup of fluid in the middle ear, which may or may not be infected)
- Eustachian tube dysfunction (blockage of the tube that runs from the middle ear to the back of the nose and throat)
- otosclerosis (a medical condition that causes thickening of the three tiny bones of the middle ear)
- choleasteatoma or glomus tumours (abnormal growths in the middle ear)
- ossicular chain discontinuity (a break in the connection between the bones of the middle ear, usually caused by trauma)
Conductive hearing loss is often treated medically or surgically. However, in cases where medical or surgical intervention is not appropriate, individuals with conductive hearing loss may be managed with hearing aids, including such special devices as bone-anchored hearing aids (BAHA) or bone conductor hearing aids.
The most common cause of conductive hearing loss, which mainly affects children, is otitis media. This is often associated with temporary or fluctuating hearing loss. This in turn can affect a child's learning, language development, and behaviour. Although it is usually easily treatable, the incidence of otitis media is significantly higher among Indigenous children, for whom it represents a serious health and educational issue. Parents who have concerns about their child's responsiveness to sound, language development, or behaviour should talk to their doctor.
