Conductive Hearing Loss

Ear infections in children are a common cause of conductive hearing loss. A less common type of hearing loss is conductive hearing loss, which occurs when there is an obstruction or damage to the outer or middle ear that prevents sound from being conducted to the inner ear. Conductive hearing loss may be temporary or permanent, depending on the cause

Causes

The causes of conductive hearing loss can be differentiated by which part of the ear they affect - either the outer or middle ear.

Outer ear

− Stenosis or a narrowing of the ear canal
− Wax impaction
− Exostoses (bone-like protrusions that can develop inside the ear canal and cause potential cause blockages)
− Otitis externa (also known as swimmer’s ear)
− Obstructions caused by foreign bodies inserted into the ear
− Microtia

Middle ear

A breach in the tympanic membrane (ear drum) caused by injury, ear infections or extreme and rapid air pressure changes
− Tympanosclerosis, a thickening of the tympanic membrane
− Otitis media (ear infection) and/or a build-up of fluid in the middle ear
− Blockages in the Eustachian tube, which connects the middle ear to the back of the nose and throat
− Otosclerosis which affects the tiny middle ear bone known as the stapes
− Abnormal growths or tumours that form within the middle ear, such as cholesteatoma or glomus tumours
− Ossicular chain discontinuity, or a break in the connection between the bones of the middle ear, caused by injury or heavy trauma

Symptoms

Because the sensitive inner ear and auditory nerve are intact, an individual suffering from conductive hearing loss primarily has difficulty with the overall loudness of sounds, but not the clarity. Individuals with this kind of loss often find that turning up the volume of the radio or television is all it takes to improve their ability to hear. The following symptoms are also consistent with this type of loss:
− Easier time hearing out of one ear than the other
− Pain in one or both ears
− Sensation of pressure in one or both ears
− Difficulty or frustration with telephone conversations
− A foul odour coming from the ear canal
− A feeling that one's own voice sounds louder or different

Treatment

There are sometimes medical or surgical treatments that can improve the hearing ability for those with conductive hearing loss. For example, conductive losses caused by wax impaction, foreign objects, abnormal growths or ear infections can often be corrected with medical treatments, like extraction of earwax, antibiotics or surgical procedures. These causes usually result in temporary hearing losses. The treating physician and hearing healthcare professional will monitor hearing ability and work with the patient to determine when and if a hearing solution is needed.
Conductive hearing losses caused by other abnormalities, like stenosis of the ear canal, exostoses, otosclerosis and ossicular chain discontinuity are more difficult to treat medically and may be considered a permanent hearing loss. These conductive losses may be treated with either standard hearing aids or bone anchored implantable devices