Causes 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 Loss
This 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 Mumbling 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 Loss
This occurs when there is a problem with the outer or middle ear. Problems in these areas usually related 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’
- Birth injuries
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 Loss
This 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
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).
Age-related hearing loss
- Age is the biggest single cause of hearing loss. As most of us grow older, the daily wear and tear on our hearing systems gradually reduces their effectiveness. When your hearing starts to weaken, it becomes more difficult to hear soft voices and high-frequency sounds, such as the voices of children and women. Sufferers of age-related hearing loss can also find it very hard to follow conversations in the presence of background noise.
- Because the loss is gradual, you may not realize that you’ve lost some of your ability to hear. Often, family members notice age-related hearing loss before the sufferer becomes aware of it.
