There are three main types of hearing loss:
- Sensorineural hearing loss
- Conductive hearing loss
- Mixed hearing loss.
Sensorineural Hearing Loss:
When someone has sensorineural hearing loss, that means that some of these nerves are missing or damaged. These nerves take sound waves (vibrations in the air) and send it to the brain, so if they’re not completely working then some of that sound won’t be able to get to the brain. Depending on how many of the nerve cells aren’t working, the level of hearing loss can vary from very little to complete deafness.
There are a lot of reasons why sensorineural hearing loss occurs. It can be present from birth, or it might happen at another time early or late in life. This can happen due to:
- Exposure to loud noise
- Head trauma
- Virus or disease
- Autoimmune inner ear disease
- Hearing loss that runs in the family
- Aging (presbycusis)
- Meniere’s Disease
- Otosclerosis – A hereditary disorder in which a bony growth forms around a small bone in the middle ear, preventing it from vibrating when stimulated by sound.
Conductive Hearing Loss:
Conductive hearing loss is a hearing loss that happens when the nerve cells in the cochlea might work fine, but sound waves can’t get to the cochlea.
This is because their cochlea would be able to recognize sound vibrations, but something is blocking the sound waves and therefore these vibrations do not reach the cochlea. Conductive hearing loss makes sounds seem as if the ear is plugged: sounds from the outside can be difficult to hear, but other sounds like your own voice or chewing on food can be heard just fine.
The blockage that causes a conductive hearing loss might be temporary or permanent, and the amount of hearing loss depends on what kind of blockage it is.
Some causes of conductive hearing loss are:
- Impacted earwax
- Malformation of outer ear, ear canal, or middle ear structures
- Fluid in the middle ear from colds
- Ear infection
- Poor Eustachian tube function
- Perforated eardrum
- Benign tumors
- Infection in the ear canal
- Foreign body in the ear
Mixed Hearing Loss:
Mixed hearing loss is a mix of different hearing losses, specifically sensorineural and conductive hearing losses. Therefore the reasons for a mixed hearing loss are a mix of the reasons for both sensorineural and conductive hearing loss.