Sensorineural hearing loss & its causes
The term sensorineural hearing loss describes two different problems: sensory loss involving the inner ear and neural loss involving the hearing nerve.
What is it?
In the past, sensorineural hearing loss was referred to as “nerve deafness”. We now know that in most cases the problem stems from the inner ear rather than from the hearing nerve. However, we continue to group the two problems together, because the inner ear and the hearing nerve are connected and need to work together.
It’s another reason why hearing loss should be treated promptly - the ‘downstream’ neural parts of the hearing system need input from the ‘upstream’ sensory parts in order to grow and stay healthy.
What are the causes ?
The causes of sensorineural hearing loss are varied but can be generally put into two categories: congenital and acquired.
Congenital hearing loss is present at birth and is the most common problem seen in newborn babies. It can be either inherited or caused by abnormal development in the fetal stages of life. Before the development of a vaccine, maternal rubella or German Measles was a common cause of congenital hearing loss.
Acquired hearing loss, which happens after birth, can be caused by a wide range of factors. These include trauma, presbycusis (age-related hearing loss), noise exposure from machinery or firearms, Meniere’s disease and meningitis. Ototoxic drugs - which damage the ear but may be necessary to treat some life-threatening medical conditions – can also trigger hearing loss. A tumour on the hearing nerve can cause the rarer neural hearing loss.
What are the signs?
When present in both ears, sensorineural hearing loss will mean you may have difficulty understanding, even when speech seems loud enough. When in one ear, you may have difficulty locating sounds or hearing in background noise.
What are the treatments for profound hearing loss?
Treatment for sensorineural hearing loss varies, depending on the severity of your hearing loss and whether you are affected in one ear or both.
Hearing aids can help most people with mild to moderate sensorineural hearing loss in both ears. For more severe levels of hearing loss, sometimes hearing aids just do not help enough. This is because sensorineural hearing loss causes sounds to become distorted. Amplifying sounds through hearing aids makes them sound louder, but not necessarily clearer. Even good quality hearing aids can sound distorted if the inner ear is severely damaged.
If you have severe to profound hearing loss and hearing aids are no longer working for you, you may want to learn more about cochlear implants. A cochlear implant is an electronic device that is surgically implanted - so it bypasses the damaged inner part of the ear to stimulate the hearing nerve directly. Unlike hearing aids which simply amplify sound, cochlear implants convert sound waves to electrical impulses in a way that mimics your natural hearing.
If you have mild to severe sensorineural hearing loss in one ear then a conventional hearing aid is the most common treatment option. However, as hearing aids require some degree of useable hearing, they can’t help in the case of profound hearing loss.
In profound losses, Baha® bone conduction implants can transmit sound through bone, from the damaged ear to the working inner ear on the other side. This makes it easier to understand speech in noisy situations and reduces the attenuation of sounds from the deaf side. If you have normal hearing or mild hearing loss in your good ear, a bone conduction implant may be a good option for you.
Please seek advice from your medical practitioner or health professional about treatments for hearing loss. They will be able to advise on a suitable solution for the hearing loss condition. All products should be used only as directed by your medical practitioner or health professional.
Not all products are available in all countries. Please contact your local Cochlear representative.