Types of Hearing Loss - A guide to Hearing Loss

There is more than one type of hearing loss which is briefly mentioned in the ‘what is hearing loss?’ section. To recap:

• Sensorineural hearing loss
• Conductive hearing loss
• Mixed hearing loss

Sensorineural hearing loss

Sensorineural hearing loss is a type of hearing loss (or deafness) which is caused by a problem in the inner ear (sensory) or the nerve pathways to the brain (neural). Damage occurs to tiny hairs within the inner ear which are responsible for transmitting sound waves to the brain

Sound waves are transmitted through the outer and middle ear as normal but it is only when they reach the inner ear that problems occur.

This can manifest itself as an inability to hear certain sounds such as women’s and children’s voices which are high pitched compared to other sounds. What tends to happen is that the sufferer becomes embarrassed in social interactions with women and/or children due to their inability to hear what they are saying.

This type of hearing loss can be a result of the ageing process; or caused by prolonged exposure to loud noises, side effects of certain medications or a viral or bacterial infection.

Sensorineural hearing loss can develop over a long period of time or suddenly occur (sudden onset). In the case of the latter, medical help must be sought as sudden onset hearing loss can lead to permanent deafness. It is non-reversible which means that treatment must be sought straightaway to prevent further hearing loss.

In a few rare cases, a benign or malignant tumour can damage the auditory pathways to the brain.

It can also occur at birth, usually as a result of a birth defect during the early development stages and is classed as a congenital disorder.

Conductive hearing loss

This is a type of hearing loss which is caused by a failed transmission of sound waves through the outer ear to the inner ear.

Sound waves do get through but are impaired whilst doing so which reduces their efficiency.

This manifests itself as an inability to hear sounds clearly. The sufferer finds that sounds are quieter in general and that conversations are difficult to follow. This type of hearing loss is temporary or permanent.

It can be caused by excess ear wax, a blockage in the inner ear or fluid discharged as a result of an ear infection. It can also be caused by the presence of a foreign body in the ear (especially in children), colds or sinusitis, adverse reaction to medication or a genetic disorder.

It can also be caused by otosclerosis.

Mixed hearing loss

This is a combination of the other two forms of hearing loss. It can involve damage to the outer, middle and inner ear which can be a result of an accident and injury.

Genetics

Some people are born with moderate to severe hearing loss (or profoundly deaf) due to a genetic disorder. This tends to occur whilst the embryo develops in the womb and is permanent. There is a condition called Usher’s Syndrome in which a person is deaf from birth but loses their site gradually over time. This person is said to be ‘deafblind’ (also known as dual-sensory impairment).

Usher’s syndrome is an inherited condition which starts with hearing loss at birth but then expands to include vision loss. Sight loss usually occurs in late childhood and as a result of retinitis pigmentosa - a group of hereditary eye conditions which affect the retina. Someone with Usher’s syndrome will require a great deal of care and support as they have to adjust to a life with both hearing and sight loss. But an independent life is possible, with the right amount of support.