Types of Hearing Loss

There are four types of hearing loss:

•   Conductive hearing loss
•   Sensorineural hearing loss
•   Mixed hearing loss and
•   Auditory Neuropathy

Conductive hearing loss can occur when there is damage or a blockage in the outer and/or middle ear. This can result in sound not being conducted adequately through the ear canal to the eardrum, or from the eardrum via the ossicles of the middle ear to the inner ear. It can be caused by earwax, a perforated eardrum, a build up of fluid in the middle ear from a cold or flu, (often referred to as ‘glue ear’), abnormal bone growth involving the ossicles, repeated ear infections and allergies. It is more common in children and indigenous populations. Medical interventions and technologies are often used to treat conductive hearing loss.

Sensorineural hearing loss occurs when there is damage or malfunction of the hair cells in the cochlear. Sensorineural hearing loss is the most common type of permanent hearing loss. Assistive technologies can help reduce the effects of sensorineural hearing loss.

A mixed hearing loss occurs when both conductive and sensorineural hearing losses are present. The sensorineural component of the hearing loss is permanent, while the conductive component may be permanent or temporary.

Auditory Neuropathy occurs when there is a problem with the auditory nerve transmitting the signal from the cochlea to the brain. The hearing loss can vary from normal to profound and hearing levels may fluctuate. Understanding speech in background noise can be a particular difficulty. The cause of auditory neuropathy includes lack of oxygen or jaundice at birth, or some neurological conditions. Assistive technologies can usually help reduce the effects of auditory neuropathy.