There are different types of hearing loss you may come across, we’ve produced this handy guide to help you understand them
There are two types of hearing loss, with different underlying causes :
These can cause different levels of hearing loss:
We take you through these terms below
Conductive hearing loss
Conductive hearing loss is the result of sounds not being able to pass freely to the inner ear. This usually results from a blockage in the outer or middle ear, such as a build-up of excess ear wax or fluid from an ear infection (especially common in children). It can also happen as a result of some abnormality in the structure of the outer ear, ear canal or middle ear – or be due to a ruptured eardrum.
The result of this type of hearing loss is that sounds become quieter, although not usually distorted. Depending on its cause, a conductive hearing loss can either be temporary or permanent.
Conductive hearing losses can often be corrected with medical management, or minor surgery.
Sensori-neural hearing loss
This type of hearing loss occurs within the inner ear.
A permanent sensorineural hearing loss is the result of damage to the hair cells within the cochlea or the hearing nerve (or both). Damage to the cochlea occurs naturally as part of the ageing process or babies can be born without fully developed hair cells resulting in a sensori-neural loss. – there are also many other things that cause sensorineural hearing loss, or add to it, such as:
- Regular and prolonged exposure to loud sounds. These sounds do not necessarily have to be unpleasant – for example, exposure to loud music can be just as harmful as exposure to loud machinery. Even short term exposure to loud sound can cause temporary deafness.
- Ototoxic drugs – some medicines are harmful to the cochlea and/or hearing nerve. These include drugs that are used in the treatment of serious diseases such as cancer but also include certain types of antibiotics
- Certain infectious diseases, including Rubella
- Complications at birth
- Injury to the head
- Benign tumours on the auditory nerve – although rare, these can cause hearing loss
- Genetic predisposition – some people are especially prone to hearing loss.
Sensorineural hearing loss not only changes our ability to hear quiet sounds, but it also reduces the quality of the sound that is heard, meaning that individuals with this type of hearing loss will often struggle to understand speech. Once the cochlea hair cells become damaged, they will remain damaged for the rest of a person’s life. Therefore sensorineural hearing loss is irreversible and cannot be cured – at least at the present time.
Hearing loss can be categorised in to 4 main levels of deafness – mild, moderate, severe or profound. These levels are determined according to the quietest sound, measured in decibels, which you can hear without the aid of a hearing device, such as, hearing aids. (learn more)
Mild hearing loss
The quietest sounds people with mild hearing loss can hear are 25-39 decibels. If you have a mild hearing loss you will find it difficult following speech in noisy environments.
Moderate hearing loss
The quietest sounds people with a moderate hearing loss can hear are 40-69 decibels. If you have a moderate hearing loss you may need to use hearing aids in order to be able to hear speech clearly and may still struggle in noisy environments.
Severe hearing loss
The quietest sounds people with a severe hearing loss can hear are 70-94 decibels. If you have a severe hearing loss you will need hearing aids to access speech and you may also rely on lipreading.
Profound hearing loss
The quietest sound people with a profound hearing loss can hear are 95 decibels or more. If you have a profound hearing loss BSL is likely to be your first or preferred language. Some profoundly deaf people may opt for a cochlear implant which allows for access to speech.