Types of hearing loss

Liam is 42 and was born profoundly deaf. His mum had rubella when she was pregnant, and Liam lived in a world of silence until last year, when he was given the gift of sound through a cochlear implant.

Donna, her mum Yvonne and her daughter McKenzie all share a genetic condition which resulted in them being deaf. Donna also had Meniere’s disease (a build up of fluid in the inner ear) during her twenties, which is further compounded her hearing difficulties.

Angela contracted a virus which damaged her hearing, and the medication Peter received for a medical condition left him deaf.

All of their hearing loss is known as sensorineural.

This means that the sound messages from the ear are not transmitted to the brain by the auditory nerve. This is the result of the hair cells in the inner ear (cochlea) not working properly.

There are numerous causes of sensorineural hearing loss, ranging from a birth defect, fluid in the inner ear, a virus or infection, noise damage, the aging process or adverse side effects from certain medications.

A cochlear implant often offers a hearing solution for individuals affected by this form of hearing loss.

Below is a diagram highlighting the area of the ear affected and brief overview of what’s wrong, the causes and the amount of hearing loss individuals affected experience.

*Sensorineural hearing loss (damage to the inner ear & hearing nerve)

In contrast, Conductive hearing loss is caused by damage to the hearing mechanisms of the ear (the ear drum or the bones of the middle ear: malleus, incus, stapes).

*Conductive Hearing Loss (damage to the middle ear and the mechanisms of hearing) 

The damage to the mechanisms of the middle ear means it can no longer conduct sound waves through the ear to the auditory nerve.

This form of hearing loss can result from:

  • Glue ear, where the bones in the middle ear and surrounded by fluid build up which decreases the ability of the small bones to move and conduct vibrations
  • Middle ear infections
  • Perforated ear drum
  • Damage to the ear from sudden pressure changes.

Often, there are varying treatments for this form of hearing loss, which is often determined by the cause of the problem.

Cochlear Implants are not a suitable treatment option for conductive hearing loss, as it does not fix the mechanics of the ear.