Causes of Hearing Loss

Main Causes and Types of Hearing Loss

There are three main types of hearing loss with different causes and features. Each type of hearing loss relates to the specific part of the hearing system where the damage has occurred.

Sensorineural Hearing Loss1 is the most common type of hearing loss. It can also be called ‘nerve deafness’ or ‘perceptive loss’. It occurs when the delicate structures of the inner ear or cochlear and/or its associated nerves are damaged. It is usually permanent and can affect sound clarity and amplification where voices may sound like mumbles or are distorted.

The most common causes of sensorineural hearing loss include:

  • Prolonged exposure to loud noise
  • Age related changes
  • Illnesses such as meningitis, measles, mumps and Menieres disease
  • Inherited factors

Conductive Hearing Loss2 occurs when there is a problem with the outer or middle ear. Problems in these areas usually relate to a mechanical disruption of the pathway of sound through to the inner ear. This results in a decrease in perceived loudness of a sound to the sufferer and can often be treated with surgery or other forms of medical management.

The most common causes of conductive hearing loss include:

Outer ear canal:

  • Blockage by ear wax, or foreign objects
  • Ear canal infection or ‘swimmers ear’
  • Bony growths in the canal known as exostoses or ‘surfers ear’

Middle ear:

  • Middle ear infection or ‘glue ear’ (a build-up of fluid) – most common in children
  • Perforated eardrum that does not heal
  • Damage to the tiny bones that conduct sound. For example Otosclerosis
  • Benign growth in the middle ear (Cholesteatoma)

Mixed Hearing Loss3 is when damage has occurred to both the middle ear and inner ear system. This can happen when there are multiple conditions co-existing or in cases of Otosclerosis.

Other Terms Used to Describe Types of Hearing Loss

Hearing loss can be classified as to:

When it occurred:

Acquired – begins after birth

Congenital – hearing loss present at birth either due to inherited or genetic factors, or other conditions like maternal health problems or birth injury

Whether it is permanent or temporary:

A temporary hearing loss can be caused by a medical condition such as glue ear or by exposure to a very loud noise on a once off basis (known as a temporary threshold shift).

1 American Speech-Language-Hearing-Association. Sensorineural Hearing Loss. [Online] Types of Hearing Loss

2 American Speech-Language-Hearing-Association. Conductive Hearing Loss. [Online] Types of Hearing Loss

3 American Speech-Language-Hearing-Association. Mixed Hearing Loss. [Online] Types of Hearing Loss