Causes of Hearing Loss
How common is it?
Hearing loss is more common than you think…and unfortunately anyone can be affected.
In fact, 3.55 million Australians have hearing loss and 49.5% of people with a hearing loss are younger than retirement age.
Even in our clinic, we have noticed that compared to 10 years ago, where we mostly saw pensioners and the age groups from 80+, now we are seeing more and more clients who are concerned about their hearing from 40+ age.
It is really important to be proactive about hearing loss and get it tested as early as possible to prevent auditory deprivation
Please see act sooner rather than later page for more interesting information on preserving hair cells and keeping them healthy.
Hearing loss can occur due to damage or problems with any part of the ear. When we test your hearing, we ask you questions about your general health, ear health and hearing history. Once we have completed your hearing test and have tested your hearing using pure tone and speech sounds, we look at the pattern from all results with your history. We can then advise you of where your damage is and the most likely cause of your loss. Please see Adult Hearing Tests for more information.
There are 3 types of hearing loss:
- Conductive loss
- Sensorineural loss
- Mixed hearing loss
Conductive Loss
Conductive loss is generally caused by a problem in the outer or middle ear which stops sound being passed through to the inner ear and nerve fibres. Some causes of conductive loss are listed below.
Wax Blockage
Wax production is a natural process. It basically acts to help protect the ear by trapping any foreign things present in the ear canal. However sometimes wax can build up to the extent that it becomes hard, black and blocks the entire ear canal. This can give a hearing loss of almost up to 40dB. It is almost as though someone has put an ear plug in your ear and reduced the sound. Most of the time, softening the ear wax with olive oil/ wax drops then getting your ears syringed/ vacuumed by your GP/ ear specialist can resolve this type of hearing loss.
Perforated Eardrum
A perforated eardrum is essentially a hole in the eardrum. This means it cannot move properly which can cause hearing loss. Some causes of perforation are:
- As a result of a bad ear infection causing fluid to build up and burst the eardrum
- A very loud sound such as an explosion which makes the eardrum move so violently that it actually perforates
- From something being pushed deep into the ear canal and poking through the eardrum e.g. cotton bud
Sometimes surgery such as a tympanic graft can fix the hole, otherwise a hearing aid may be required. Usually people with perforated eardrums should be very wary of getting water in their ears. We can make custom swim plugs for use with showering or swimming to protect the ear if a perforation is evident. See Ear Protection
Ear Infection
There are two types of ear infections. One is called Otitis Externa which means an infection of the outer ear. This can present as dryness, irritated skin and weeping. Medication, antibiotics or topical cream may be required.
A middle ear infection, called Otitis Media is quite common but can be very painful. Typically the eustachian tube (which is the tube that opens when you are flying in an aeroplane and your ears ‘pop’) jams shut preventing air from getting in to the middle ear cells. The eardrum then gets sucked back so it does not move well and you feel as though you are quite deaf.
If this progresses to the next stage, fluid is then secreted into the middle ear space and the eardrum becomes red, bulging and inflamed. If the fluid pushes too much pressure onto the eardrum, it can then perforate and pus/ fluid then drains into the ear canal.
Medication and antibiotics are usually required, although sometimes a chronic ear infection can remain which has to be monitored and hearing loss helped through a hearing aid.
Otosclerosis
Sometimes a build up of calcium on the middle ear bones can cause them to fuse and then not move as they should to pass the sound on through to the inner ear. This causes a hearing loss.
This is a genetic condition usually affecting women and can occur at times of hormonal changes such as pregnancy or menopause. Generally surgery or a hearing device is required to resolve these hearing issues.
Sensorineural Hearing Loss
Noise Damage
Being exposed to loud noise, especially over extended periods of time can affect the tiny inner ear hair cells of the cochlea. Each time the ear is exposed to loud noise, the little inner ear hair cells get knocked flat by the sheer force of the vibrations that are sent through the eardrum and middle ear bones onto the cochlea. Usually these hair cells can recover and stand upright again. This is called Temporary threshold shift. This is exactly what happens when you have been at a loud concert and afterwards you feel ‘deaf’ with ringing in your ears, but by the next morning, your hearing is back to normal.
However repeated exposures to the loud noise, such as working with machinery, factory noise or tools, the little hair cells can no longer recover. This is called Permanent Threshold shift and the end result is a permanent high frequency hearing loss.
A typical complaint of a person with a high frequency noise induced hearing loss is being able to hear people talking but not all that clearly, particularly in background noise. This is due to the damage to the tiny hair cells which can no longer process sound properly and have trouble if there is competing noise in the background.
The sooner you act on this kind of hearing loss by wearing properly fitted hearing aids, the better you can save your ears by stimulating the remaining hair cells to keep active. See Auditory Deprivation
Also, being very mindful of wearing ear protection in loud noisy places can help protect your hearing (eg Clipsal, concerts). We can make custom ear plugs which allow a pleasant listening experience but at safe levels for your ears. See Ear Protection
If you’re exposed to sounds above 85 dB, you may be putting your hearing at risk. Here is a helpful chart which shows the loudness levels of certain sounds.
Presbyacusis or Age Related Loss
Unfortunately, as we get older our bodies get a little worn out and this includes the ears. Generally the high pitches tends to be lost first as they are the most activated in the first turn of the inner ear. See How We Hear
This usually results in a loss of clarity more than volume. Quite often, you can hear the person talking but it is not clear.
It is really important to stimulate the remaining hair cells to prevent further loss just from Auditory Deprivation.
Meniere’s Disease
Meniere’s Disease is caused by excessive fluid in the inner ear and balance organs of the ear. This can result in quite debilitating symptoms like loss of balance, fluctuating hearing loss, tinnitus and a feeling of fullness in the ears.
Meniere’s Disease can exist for quite a long period of time with varying severity, and eventually reaches the ‘Burnt Out’ phase where symptoms are stable but the hearing is permanently damaged. The actual cause of Meniere’s disease is not known but factors such as genetics, auto immune and viral influences have been linked with Meniere’s Disease.
Usually the hearing loss is a low frequency or flat hearing loss which can make things sound softer overall but also create distortion.
Being checked by an ear, nose and throat specialist is important in this case with hearing rehabilitation through us happening afterwards or alongside medical evaluation.
Sudden Hearing Loss
Quite rarely, hearing can drop suddenly and permanently. The cause is generally unknown although many cases of sudden hearing loss are caused by an interruption of the blood supply to the tiny hair cells of the inner ear. This causes death of the cells and a remaining permanent hearing loss.
If this does occur, you are best off seeing your GP as soon as you possibly can, because in some cases immediate steroid and oxygen use can help. However, there is usually a resulting permanent hearing loss.
Depending on the severity and location of the damage, hearing aids can definitely help.
Ototoxic Medications
There are some medications where a side effect is hearing loss. These are called ototoxic medications and there are about 200 medications currently that are considered ototoxic. Usually the condition that the medicines are used for, such as cancer, heart disease and serious infections are more severe than hearing loss and it is a risk worth taking if indicated by your doctor.
People with hearing loss related to ototoxic medications are usually successful with hearing aids.
Mixed Hearing Loss
A mixed hearing loss can result from a combination of middle ear and inner ear problems, such as a ear infection as well as a noise induced loss. Usually an ear, nose and throat specialist evaluation alongside our tests and a fitting of hearing aids is recommended. This ensures that any medical or surgical intervention can happen as well as hearing aid rehabilitation if needed.
We are happy to write referral reports and do so for any cases we recommend medical checking.
