There are different causes, types and degrees of hearing loss which need to be taken into account when determining the best treatment. Identifying which type of hearing loss you have is the first step in finding an ideal solution.
The types of hearing loss
There are four types of hearing loss, depending on which part of the ear the hearing loss originates: conductive, sensorineural, mixed and neural hearing loss.
There are three parts to the ear: the outer ear, the middle ear and the inner ear. If your hearing loss originates from the outer ear or middle ear, you have a conductive hearing loss.
If your hearing loss stems from a problem in the inner ear, it is referred to as sensorineural hearing loss or inner ear hearing loss.
Some people have a combination of a conductive and sensorineural hearing loss. This is called a mixed hearing loss. Depending on the severity, a hearing aid or hearing implant may help.
If the hearing nerve is damaged or absent, sound cannot reach the brain. This rare type of hearing loss is called neural hearing loss.
What is a conductive hearing loss?
When there is an interruption or blockage in the outer or middle ear, sound cannot take usual way to the inner ear.
Problems with your ear canal, ear drum or the tiny bones in the middle ear called ossicles (hammer, anvil and stirrup) may cause this interruption or blockage, leading to a conductive hearing loss. If you have a conductive hearing loss, everything will sound muffled and too soft.
What are the most common causes of conductive hearing loss?
- Outer ear infections
- Excess earwax in the ear canal
- Fluid in the or middle ear
- Middle ear infections (otitis media)
- Perforation of the eardrum
- Malformed outer or middle ear
- Otosclerosis (bony growth around the ossicles)
A conductive hearing loss is often temporary, with a variety of treatment options. They include medication, surgery, conventional hearing aids and hearing implants.
What is a sensorineural hearing loss?
If your hearing loss stems from a problem in the inner ear, it is referred to as sensorineural hearing loss or inner ear hearing loss. The nerve cells in the hearing organ of the inner ear, the cochlea, are damaged or missing. They look like tiny little hairs, which is why they are termed hair cells. They normally convert incoming sound to electrical pulses and send it on to the hearing nerve and the brain. Depending on how many hair cells are damaged, a sensorineural hearing loss may be mild, moderate, severe or profound.
What are the most common causes of sensorineural hearing loss?
- Accidents involving a blow to the head
- Severe illnesses (e.g. meningitis or mumps)
- Infectious diseases during pregnancy (e.g. rubella)
- Malformations of the inner ear
- Ototoxic drugs
A sensorineural hearing loss is usually permanent. Medication or surgery usually cannot remedy an inner ear hearing loss. Treatment options include hearing aids or cochlear implants, depending on the severity of the hearing loss.
Neural hearing loss
If the hearing nerve is absent or damaged, sound cannot travel from your ear to your brain. People with this condition suffer from a neural hearing loss, which is permanent. They have a profound hearing loss (“deafness”).
What are the most common causes of neural hearing loss?
- Tumors situated on the hearing nerve
- Hearing nerve is malformed or absent since birth
The only treatment option available for neural hearing loss is an auditory brainstem implant, a hearing implant that is implanted into the hearing centre of the brain. Other treatments such as medication, hearing aids or cochlear implants, cannot remedy a neural hearing loss.