Sensorineural vs. Conductive Hearing Loss | Knowing the Difference

If you are experiencing a hearing loss, you are usually more worried about getting your hearing back than you are about which type of hearing loss you have. 

However, knowing which form of hearing loss you are experiencing is an important part of how your hearing loss is treated. In some cases, hearing aids are the right solution, but in others, procedures like earwax removal or more complex surgical procedures might be the answer to restoring your capacity to hear. 

At Hear In Texas we have successfully diagnosed and treated both conductive hearing loss and sensorineural hearing loss for thousands of patients in New Braunfels and the surrounding communities. 

Let’s start off by defining each of the two types of hearing loss.

Defining Conductive Hearing Loss 

To remember this kind of hearing loss, think of what the word conduction means: passing through. It is most often used when talking about electricity being able to pass through a substance like copper.  

When you are experiencing a conductive hearing loss, sound does not pass through the auditory pathway, or the pathway where sound enters your outer ear, continue through the ear canal to the middle ear, and into the inner ear, where it is transformed into sound signals and transmitted to the brain. 

Essentially, with conductive hearing loss, something along the pathway is preventing the conduction of sound from passing through. In many cases, the removal of the obstruction allows hearing restoration. 

Typically, hearing aids are not an effective treatment for conductive hearing loss because even the amplified sounds they produce cannot penetrate through whatever is already interrupting or blocking sounds from passing through the auditory pathway. 

What causes conductive hearing loss? 

A blockage along the auditory pathway causing conductive hearing loss typically stems from one or a combination of the following circumstances: 

• Blockage by earwax or a foreign object in the ear canal 

• The presence of fluid, infection, or bone abnormality in the middle ear space 

• An injury to the eardrum 

Defining Sensorineural Hearing Loss 

In contrast to conductive hearing loss, sensorineural hearing loss is related to the neural or nerve part of the auditory pathway, most specifically the outer nerve cells in the Corti or the nerve cells inside the cochlea that transform sound into electronic signals the brain can interpret as sound. 

When these nerve cells become damaged or deteriorate due to aging, known as presbycusis, they are permanently unable to provide the sound signals your brain needs to interpret or hear sounds. 

With sensorineural hearing loss, hearing aids are the most likely solution to help with hearing, but they cannot cure it. When hearing aids do not provide an adequate solution, electronic implants, or cochlear implants, are sometimes used to assist patients with a profound hearing loss. 

What causes sensorineural hearing loss? 

Sensorineural hearing loss typically develops gradually due to one or more of the following conditions: 

• Age deterioration (presbycusis) – most common 

• Exposure to loud noise (noise-induced hearing loss or NIHL) – second most common 

• Traumatic injury to the inner ear or auditory nerve system 

• Diseases that affect the nervous system 

• Ototoxic drugs that damage nerve cells 

• Genetic condition 

Mixed Hearing Loss 

Although there are only two types of hearing loss, some people can have both of them at the same time. There are three ways to develop a mixed hearing loss: 

• The person already had a sensorineural hearing loss and developed a conductive hearing loss afterward. 

• The person already had a conductive hearing loss and developed a sensorineural hearing loss afterward. 

• There is simultaneous development of both types due to a genetic condition or traumatic injury. 

Addressing mixed hearing loss is particularly challenging because even amplified sound from a hearing aid cannot penetrate through a blocked or obstructed auditory pathway. In most cases, conductive hearing loss is treated first in order for hearing aids to be effective in the treatment of the sensorineural hearing loss. 

An Accurate Diagnosis Is Critical for Proper Treatment 

One of the biggest drawbacks of being able to self-diagnose and treat your hearing challenges on the internet is the fact that a simple pure tone test cannot identify which of the two types of hearing loss you are experiencing. 

Unfortunately, many self-diagnose hearing loss and spend money on expensive over-the-counter or direct-to-consumer hearing aids that do not adequately treat their specific type and severity of hearing loss. 

Identifying the type and severity accurately requires a comprehensive hearing assessment by a hearing care professional. So, you can understand the difference, here is a basic outline of what is typically included in a comprehensive hearing assessment: 

1. A discussion about the symptoms of your condition, your medical and family history, your lifestyle, occupation, and the activities you participate in. 

2. A physical examination of your ears. This is one of the most significant steps in the process because it often identifies an obstruction from earwax, a foreign object, or a growth or inflammation that could be blocking the conduction of sound through the ear canal. 

3. Besides the typical pure-tone hearing tests, a comprehensive hearing assessment also includes a tympanometry and a bone conduction hearing test. Tympanometry measures the capacity of the middle ear to pass sounds from the outer ear to the inner ear, and a bone conduction test bypasses the auditory pathway to evaluate the condition of the inner ear. 

4. Additional tests may be used to further clarify the severity of your condition as well.

This testing process allows your hearing care professional to not only diagnose which type of hearing loss you are experiencing but also its level of severity and the proper course of treatment to either fix the conduction issue or help enhance your hearing capacity with hearing aids. 

Common Symptoms of Hearing Loss 

In general, it is difficult to tell whether you are experiencing a conductive or sensorineural hearing loss without testing. However, here are the most common symptoms of hearing loss: 

• Muffled speech and other sounds 

• Trouble understanding words, especially in a noisy place 

• Trouble distinguishing certain consonants 

• Often asking others to speak more slowly, clearly, and loudly 

• The need to turn up the volume of the television or radio 

• Avoidance of some social settings 

• Being bothered by background noise or sudden noises (hyperacusis) 

• Ringing in the ears, aka tinnitus 

• Unsteadiness on your feet, especially navigating down a flight of stairs or over uneven terrain 

• Stuffiness in your ears, dizziness, and vertigo 

Sudden Sensorineural Hearing Loss or Sudden Deafness  

Sudden sensorineural (“inner ear”) hearing loss (SSHL), commonly known as sudden deafness, is an unexplained, rapid loss of hearing either all at once or over the course of a few days, typically in just one ear. 

People often discover SSHL upon waking up in the morning, but others recognize it when they use the deafened ear, like when talking on the phone. In some cases, there is a loud “pop” before your hearing disappears.  

Symptoms of SSHL typically include: 

• Ear fullness or ache 

• Dizziness 

• Ringing in the ear 

To achieve the best treatment outcomes, SSHL must be treated within two weeks of onset. About half of people with a sudden sensorineural hearing loss recover some or all of their hearing spontaneously, but delaying diagnosis and treatment can decrease treatment effectiveness. Seeking treatment within the first 72 hours provides your best opportunity to respond positively to treatment. 

When Should You Contact an Audiologist? 

In the case of sudden sensorineural hearing loss, contacting an audiologist ASAP is critical.  

If you are experiencing any of the hearing loss symptoms listed in this publication, scheduling a comprehensive hearing assessment with an audiologist will not only provide a more accurate diagnosis but also allow for the proper treatment rather than simply assuming you need to buy a hearing aid. 

In the case of sensorineural hearing loss, if you are frequently exposed to loud noise or have gone through chemotherapy treatment, you are at an increased risk of developing the condition and should schedule a hearing assessment to monitor your condition. 

In addition, if you are over the age of fifty, you should begin scheduling frequent hearing tests to monitor the progress of age-related hearing loss.