What are the causes of Sensorineural Hearing Loss
Approximately one in six Australians suffer from some type of hearing loss. Sensorineural hearing loss is the most common type of hearing loss to be diagnosed. Its prevalence is exceptionally high amongst adults over 65 years of age. Understanding what causes sensorineural hearing loss can help manage your hearing health effectively.
Types of Hearing Loss
There are three main types of hearing loss that an individual can be diagnosed with through comprehensive audiological assessment, this includes:
- Sensorineural hearing loss
- Conductive hearing loss
- And mixed hearing loss
Today, we will focus on sensorineural hearing loss. First, however, it is crucial to understand the other types of hearing impairments that could affect you.
Conductive hearing loss
Conductive hearing loss refers to a hearing loss caused by physical obstruction of the middle or outer ear. This can include hearing loss caused by ear infections, poor Eustachian tube function, occluded earwax, eardrum perforation and so on.
It is essential to consult your Audiologist and medical practitioner for the appropriate diagnosis and treatment for your condition. For example, if you have been diagnosed with conductive hearing loss, the treatment options may look different from sensorineural hearing loss or mixed hearing loss.
Sensorineural hearing loss
On the other hand, sensorineural hearing loss refers to damage to the inner ears and is commonly referred to as nerve-related hearing loss. In most cases, this is permanent. However, this may not necessarily apply to all patients. Therefore, it is essential to consult your Audiologist and GP to ensure the appropriate diagnosis of sensorineural hearing loss. Then, you can discuss the different types of treatments available to you, including hearing aids and Cochlear implants.
Mixed hearing loss
Mixed hearing loss is a combination of both conductive and sensorineural hearing loss. It involves an obstruction of the outer or middle ear and damage to the inner ear. Individuals diagnosed with mixed hearing loss should always seek consultation and advice from their Audiologist and medical specialists to resolve the conductive component of the hearing loss first, then seek treatment options for the underlying sensorineural part of the hearing loss.
The Mechanisms of Sensorineural Hearing Loss
One of the most common causes of sensorineural hearing loss is losing hair cells in the inner ear. These hair cells, known as Cochlear sensory cells or stereocilia, play a vital role in the mechanism of hearing. They detect sounds and transmit information through to the auditory nerve running up to the brain.
In most cases of sensorineural hearing loss, irreversible damage has been done to the hair cells, which have limited repair capacity, resulting in permanent damage to the cochlea. Hence, sensorineural hearing loss is often permanent.
Causes of Sensorineural Hearing Loss
Causes of sensorineural hearing loss are split into two categories, including acquired or congenital.
Causes of acquired sensorineural hearing loss
Acquired sensorineural hearing loss refers to hearing loss that is developed after the individual was born and usually occurred later in life, depending on other factors involved. Some of the most common causes are listed below:
Age-related sensorineural hearing loss is referred to as presbycusis. This is a common condition, especially in populations over 65 years of age. However, age-related hearing loss tends to be diagnosed much later than other types of sensorineural hearing loss due to the gradual nature of the hearing loss, occurring typically in both ears. As a result, the symptoms often go unnoticed or neglected for years. Some of the early signs of presbycusis include experiencing difficulties hearing in a crowd or a noisy environment.
Exposure to loud noise
Sensorineural hearing loss caused by exposure to loud noise is referred to as noise-induced hearing loss. The individual does not have to be exposed to prolonged or extended periods of exposure to cause damage to the cochlea. Noise-induced hearing loss can be caused by a one-time exposure to sudden loud noise or noise over 85 decibels.
This can include exposure to gunfires, explosions, and loud blasts of sounds. Listening to any loud noise over 85 decibels is harmful to the inner ears, but the risk of noise-induced hearing loss increases with the period of exposure.
There are many other causes of acquired sensorineural hearing loss. This can include:
- Head trauma
- Autoimmune disease
- Viral infections
- And ototoxic medications
Causes of congenital sensorineural hearing loss
Congenital hearing loss, on the other hand, has a much lower prevalence in the Australian population. It refers to hearing loss developed from pregnancy or birth. In most cases, this is detected early on through newborn hearing screening, which allows for early intervention through hearing aids and implants to prevent any impact on speech and language development.
The causes of congenital hearing loss can range from infectious diseases during pregnancy, including measles, mumps and rubella, genetic compositions, prematurity, and CHARGE syndromes.
Preventing Further Damage to the Inner Ear
Some causes of acquired sensorineural hearing loss can be prevented, including noise-induced hearing loss. Existing damage may be irreversible; however, further damage can be avoided with the proper preventative measures. Some preventative measures include:
Being conscious of loud noise consumption
Be aware of your surroundings and listening environment. If you find yourself in an environment where you have to raise your voice to speak to someone who’s just a meter apart, the listening environment is likely to be above 85 decibels. Whenever possible, make sure to turn down the volume of music, television, radio or speakers to a safe listening level below 80 decibels.
Using hearing protection whenever necessary
Hearing protection aims to reduce the surrounding noise from a potentially dangerous level to a safe listening level for you to prevent noise-induced hearing loss. It is essential to ensure these are implemented in work environments with high levels of noise, such as construction sites, mining and shooting ranges.
Taking a break from loud noise
Ensure that your ears are given a rest, from noisy activities to quieter listening situations or activities. The duration of the noise exposure can significantly increase the risk of noise-induced hearing loss. Hence, it is crucial to implement breaks in between exposure to loud noise.
Sensorineural hearing loss is a common hearing impairment amongst Australians – especially those over 65. Undergoing a comprehensive audiological assessment will help you better understand the type and severity of any hearing loss you may have. This will allow you to take charge of your hearing health and move forward with the appropriate treatment methods.
Attune’s accredited Audiologists offer access to the full range of medical hearing services and provide professional care in a relaxed environment. If you’re ready for your annual hearing checkup, give us a call at 1300 736 702 or book your hearing test online with one of our Audiology clinics near you.