Types of deafness
The ear is very sensitive and is made up of many different parts. Sound is collected by the outer ear then converted into vibrations by the ear drum. These vibrations then travel through the middle ear and into the inner ear. The cochlea (a small spiral like structure) then converts these vibrations into electrical impulses, which are sent through nerves to the brain for processing.
The different types of deafness
Studies suggest that of the 10 million people in the UK who have a level of hearing loss and over 800,000 of us are severely or profoundly deaf. However, no two people experience deafness in the same way as there are many different types and ranges of hearing loss.
There are many reasons why a person is unable to hear or understand sounds. It can be caused by problems with the sound travelling into the inner ear, or it could be a nerve complication that means the inner ear can no process sounds or send information to the brain.
There are two reasons why someone may be deaf, and people will have a different experience of deafness depending on how they lost their hearing.
1. Deaf from birth
- This is a term we use for someone who has never had hearing – they may be born deaf due to a hereditary reason or because of infections or complications during pregnancy
- Depending on circumstances, they may use British Sign Language as their first language, or need extra support (like speech and language therapy) to acquire and use written and spoken English
- Generally (depending on their experiences and upbringing) people that are born deaf prefer to see themselves as a linguistic minority rather than disabled.
2. Deafened (or acquired profound hearing loss)
- This is used for someone who has grown up with normal hearing, but may have lost it due to a medical or other physical reason. Sometimes, it can just happen overnight.
- They usually communicate through written and spoken English as first language
- Sometimes, deafened people find themselves isolated as they have to adapt very quickly to using other forms of communication – like lip-reading
- Deafened people often rely on equipment that can help them to hear small fragments of the world around them, which can make it easier to communicate.
The range of deafness
Have you ever spoken to someone who is deaf and been surprised how well they can communicate? Most forms of deafness allow people to grasp a fraction of the conversations around them. There is a range of how much deafness affects different people.
- Mild deafness: People who are hard of hearing who can pick up most of the conversations around them in the right environment. In a place with a lot of background noise it is harder to focus their attention on one particular place.
- Moderate deafness: Those with moderate deafness find it hard to follow speech in most environments, although hearing loss equipment like hearing aids can really improve their understanding.
- Severe deafness: People with this form of deafness are usually unable to hear any speech unless they are using a hearing aid.
- Profound deafness: Profoundly deaf people will hear no speech, even with the help of having a hearing aid.