The Different Types of Hearing Loss & How They Occur

Different Types of Hearing Loss

Hearing loss affects 400 million people worldwide and one in every six Australians

Depending on the type of hearing loss you have, it may affect your day to day life differently. 

Today we will be discussing the different types of hearing loss, how they occur and the risk factors associated with each.

If you think you or someone you know may be experiencing hearing loss, continue reading.

What is Normal Hearing?

To understand hearing loss, we first need to learn what constitutes normal hearing. 

To hear sound accurately, all three parts of the hearing system (inner, middle and outer ear) need to be intact and unimpeded to function properly. 

Normal hearing is considered to be 20dBHL. Therefore, when any part of an individuals hearing sits above that threshold, they have a hearing loss.

Hearing is assessed across frequencies, typically from 250Hz (low frequency) to 8000Hz (high frequency). 

What Are the Different Types of Hearing Loss?

Hearing loss can be present for many reasons, and as a result, the configuration, type and degree of hearing loss can vary significantly. 

There are three different types of hearing loss, and they can differ in severity from mild to profound. 

The types of hearing loss include:

  • Sensorineural Hearing Loss: This hearing loss occurs when there is damage in the cochlea due to injury to the hair cells or hearing nerve. This is the most common type of hearing loss found in adults.
  • Conductive Hearing Loss: This hearing loss is caused by problems in the ear canal or middle ear, which prevent sound from passing through the outer and middle ear. This hearing loss can be short or long-term, depending on the recurrent nature and medical treatment. 
  • Mixed Hearing Loss: This term is used when both sensorineural and conductive hearing loss is found in the same ear.

What Factors Contribute to Hearing Loss?

Several factors can contribute to hearing loss, such as: 

  • Medical: This can include genetics, meningitis and other infections, complications at birth, otosclerosis, otitis media, perinatal morbidities, hyperbilirubinemia and ototoxic medicines
  • Lifestyle & Environment: This can include smoking, exposure to loud sounds, age-related sensorineural degeneration, nutritional deficiencies, trauma to the ear or head and work-related ototoxic chemicals. 

outcome of our hearing

So, how do these factors impact the outcome of our hearing?

  • Genetic characteristics are seen in congenital sensorineural hearing loss and middle ear conditions. 
  • Biological factors, such as recurrent ear infections or health conditions like diabetes, can increase the severity of hearing loss.
  • Lifestyle choices, such as smoking and exposure to loud noises, can impact the severity of hearing loss. 

Causes of hearing loss can happen at any stage of life, but people are most vulnerable when they are very young or above 65.

Children are most at risk before birth and in infancy because it’s a critical development period for the hearing system and acquiring speech and language. 

In order adults, the risk factors are compounded by the deterioration of cognitive function. The amount and type of hearing loss in adults are also influenced by health, genetics and lifestyle over a lifetime.

What is the Most Common Type of Hearing Loss?

The most common types of hearing loss Audiologists tend to see in a clinical setting are age-related sensorineural hearing loss in adults and conductive hearing loss in children. 

The World Health Organisation (WHO) found a high percentage of age-related hearing loss (presbycusis), noise-induced hearing loss (NIHL) and otitis media (OM) in communities globally. As a result, they consider these causes of hearing loss to be particularly important to public health and identify their ability to be treated medically and through rehabilitation.

Let’s take a look at the conditions below

1. Otitis Media

Otitis media is the inflammation of the middle ear and includes a range of suppurative (infection) and nonsuppurative (no infection) ear conditions. This condition is quite common in children under two years of age and is usually resolved with medical attention (ASHA). 

However, the build-up of fluid or pus in the middle ear cavity can lead to perforation of the eardrum, and long-term exposure to infection can cause erosion of the ossicle bones. This can result in life-threatening complications, sensorineural hearing loss or a more significant hearing loss. 

Otitis media produces a reduction in the volume and clarity of the sound it receives. Therefore, it sounds dull or muffled, which is problematic for children developing speech and language. Suppurative otitis media is estimated to cause hearing loss in over 98.7 million people. 

2. Age-Related Hearing Loss (presbycusis) 

Age-related hearing loss, or presbycusis, occurs over a lifetime due to causes such as noise exposure, genetics, and ageing. This hearing loss is very common in people over 60. 

A significant concern for the senior adult population is that they’re at higher risk of dementia if their hearing loss is left untreated. 

3. Noise-Induced Hearing Loss

Noise-induced hearing loss (NIHL) results from permanent damage to the eardrum or cochlea due to exposure to loud sounds. NIHL can occur through: 

  • Recreation (concerts, shooting guns). Hazardous levels of sound during leisure activities are estimated to be responsible for 50% of people aged 12-35 years being at risk of hearing loss. 
  • Occupation (pilots, carpenters). Dangerous levels of sound in the workplace are responsible for up to 21% of hearing loss in adults. 
  • Environment (living next to a train). 

In addition to exposure, the volume of the sound, length of time exposed and how close you are to the source of the sound impacts the amount of damage that can occur (ASHA). 

To Sum it Up 

Regardless of the severity or type of hearing loss, the effect on people’s lives depends on whether it’s successfully treated medically or with rehabilitation, such as hearing aids. 

There is much evidence identifying that untreated hearing loss negatively affects people’s daily lives. The impact includes poor quality of life, social isolation and physical and mental deterioration. In addition, it also affects the relationships with family and friends.

If you or someone you know has been diagnosed with hearing loss and suggested hearing aids, check out the range at EarDeals. We offer a variety of different hearing aids at affordable prices.

Visit our website or email us for more information. 

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