Mixed hearing loss – a combination of conductive and sensori-neural hearing loss

Depending on where you are experiencing problems in your ear will determine what type of hearing loss you have and what help you can get to improve your particular situation. If you have not already done so, you might find it helpful to read my previous posts. If you think a picture of the auditory or hearing system would be helpful while you read this post, simply, type, “anatomy/images of the ear” into your favourite browser and you will see many links to pictures of the ear.

Previous posts have focused on two different types of hearing loss: conductive and sensori-neural. Today’s post will focus post on mixed hearing loss which occurs when a person has a sensori-neural hearing loss but may experience some conductive hearing loss as well.

Generally speaking, sounds are “conducted” from the environment around us down our ear canals (outer ear), causing the ear drums to vibrate. The movement of the ear drums causes the bones in the middle ear to vibrate against the oval windows which sit at the entrance of the inner ear. The inner ear hair cells change the vibrations from the middle ear into electrical impulses which are sent along the auditory nerve to the brain which makes sense of the things we hear around us.

Because the outer and middle ears are responsible for “conducting” sounds to the inner ears, anything that can go wrong with the outer and/or middle ears result in “conductive” hearing loss. Some people say it is like listening under water. They feel like their ears are plugged. As well, people with conductive hearing loss tend to speak softer than usual because they hear their own voice loudly.

Most conductive hearing losses are temporary and are resolved following medical treatment such as medication and/or an operation. Conductive hearing losses can also be permanent and may require hearing aids or implantable bone-anchored hearing implants.

Sensori-neural hearing loss, typically referred to as “nerve deafness”, occurs when damage most often occurs in the “inner” ear but can also occur along the hearing nerve.

Approximately 90% of people who have hearing impairment have sensori-neural hearing loss, making it the most common type of hearing impairment. Generally speaking, sensori-neural hearing loss is permanent and irreversible.

In the vast majority of cases, sensori-neural hearing loss is not medically or surgically treatable. However, most people with sensori-neural loss notice a great deal of benefit from wearing some form of amplification devices (hearing aids, bone-anchored hearing aid (BAHA), cochlear implants, etc.).

A mixed hearing loss occurs when a person experiences a combination of conductive and sensori-neural hearing loss. There may be problems in the outer and/or middle ear as well as the inner ear. One example of a mixed hearing loss is a conductive loss due to a middle-ear infection or wax build up combined with a sensori-neural loss associated with aging.

I have seen several patients over the years who have developed a sensori-neural hearing loss and who wear hearing aids. Occasionally, these individuals develop an ear infection or wax build-up in their ear canals. These conditions may cause more hearing loss. Most often these people will complain that their hearing aids are not loud enough or think that there is something wrong with their hearing aids.

In such instances, I would examine the ear canals and ear drums and perform a battery of tests to check for any changes. Typically my tests would indicate that there is a conductive component to their hearing loss.

I would recommend them to their family physician with a copy of my most recent results.The doctor would review my results and check the patient’s ears for any sign of ear infection or wax. Some of the clients may be referred to an ear, nose and throat doctor.

Typically, the hearing loss associated with these conditions is temporary and would return to where it was before the conductive portion of the hearing loss. Once the conductive portion of the hearing loss is gone, the hearing aids would perform the way they did before the condition. The person would still have the sensori-neural portion of the hearing loss but the conductive hearing loss would be gone.

Treating any hearing loss depends on prompt diagnosis and treatment. Whenever a person experiences some form of hearing loss, they should be evaluated as soon as possible by an audiologist and physician to explore all potential treatment options.

Glen Sutherland, MCISc
Audiologist

Disclaimer
Please note that the information in this blog is presented for the purpose of providing information and should not be used for medical diagnosis or treatment nor should it be used in place of medical advice from your doctor or hearing health care professional.

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2 responses to “Mixed hearing loss – a combination of conductive and sensori-neural hearing loss

  1. Many Thanks, Rosemary. The information presented on your blog is so lucid and so very well presented. I am enjoying the ”learning” curve: the understanding of the ear’s anatomy and our hearing capabilities. I will be having my hearing tested within the next two months, so thanks again.

  2. Thank you… am becoming a veritable fount of knowledge. It is all interesting and helpful.

    Shirley

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