Hearing loss can be categorized into 3 types:
Conductive hearing loss
Conductive hearing loss occurs when sound cannot be conducted to the inner ear (the hearing nerve) properly. Causes include:
- A build-up of earwax
- A build-up of fluid in the middle ear
- Middle ear infection
- Perforated eardrum
- A foreign body
- Abnormal bone growth in the middle ear (otosclerosis)
These conditions may affect one or both ears and can often be cured by medicine or surgery.
Sensorineural hearing loss
This is the most common form of hearing loss and occurs when there is deterioration of the hair cells in the inner ear. It can be caused by a wide range of conditions but most commonly by the aging process.
Sensorineural hearing loss is a natural part of aging, but other factors may include:
- Traumatic exposure to noise
- Head injury
- Viral infections of the inner ear and auditory nerve
- Some drug treatments
- Family history
This type of hearing loss is permanent and usually affects both ears.
Mixed hearing loss
Mixed hearing loss is a combination of both conductive and sensorineural hearing loss.