What causes hearing loss?

You are not alone: it is estimated that 10% of the world’s population has a hearing loss. Everybody loses some hearing sooner or later. It’s perfectly normal. The hearing loss will however vary in degree and age/cause of onset. In general, we talk about three types of hearing loss:

  • Sensorineural hearing loss
  • Conductive hearing loss
  • Retrocochlear hearing loss

Sensorineural Hearing Loss
Sensorineural hearing loss will likely be present due to some level of damage to the delicate hair cells in the inner ear. As a result of the damage the hair cells are no longer able to convert the sound waves they receive into electrical nerve impulses. This attenuates or decreases the brain’s ability to perceive sound. Hair cell damage can be caused by:

  • Age
  • Genetic disposition
  • Exposure to very loud noises
  • Certain medical treatments such as chemotherapy and radiation
  • Virus infections in the inner ear
  • Increased intracochlear pressure
  • Head Injury

A sensorineural hearing loss can in most cases be remedied with hearing aids.

Conductive Hearing Loss
A conductive hearing loss is caused by an abnormality in function found either in the ear canal, the tympanic membrane (ear drum) and/or the middle ear. This means that sounds from the outside world are not channeled in a normal manner through the ear canal and the middle ear to the inner ear. The most common causes of a conductive hearing loss are:

  • Ear wax or foreign body
  • Perforated ear drum
  • Fluid in the middle ear
  • Middle Ear infections
  • Unusual bone growth in the middle ear
  • Interrupted ossicular chain
  • Missing ear canal

In the case of conductive hearing loss, hearing can in some cases be restored through surgical procedures. This type of hearing loss is very effectively remedied with hearing aids.

Retrocochlear Hearing Loss
A retrocochlear hearing loss is caused by disturbance either in the brain or the auditory nerve. This makes impairs the brain’s ability to perceive sound. Possible causes of Retrococlear hearing loss are:

  • Tumors
  • Brain haemorrhage
  • Fracture