The Reasons for Hearing Loss
Reasons behind Hearing Loss
In this section we will go through some of the more common reasons for hearing loss. We will have an overview of some of the less common causes as well. Don’t forget to read the how hearing works page first to get a better understanding of your hearing. These may not relate to your hearing in every case and some symptoms may be similar to other conditions, however if anything you read in this section relates to yourself please seek medical advice.
Hearing loss may have several different causes. We have come up with a fairly comprehensive list of what we believe to be the most common causes of hearing loss. Hearing loss can be classified into a couple of main groups; Sensorineural hearing loss and Conductive hearing loss. We will focus first with sensorineural loss
Ageing is fairly self-explanatory, as we grow older the cells in our body decompose a quicker rate. This decline generally will see a failing of certain areas such as our eyes and ears. Unfortunately, this is something we cannot yet get away from and it will happen eventually to all of us.
Again, this is pretty straight forward. From time to time we may be involved in an accident of sorts. If you are unlucky enough to really hit your head, you may have dislodged or broken a part of the hearing system.
Excessive noise exposure
This is normally overlooked as being an issue. Noise exposure is usually one of the bigger causes of hearing damage. It is due to when the loud noises hit the hair cells in the inner ear. If the sound is over 85dB in the work place they should provide ear protection. However, if the noise still exceeds 87dB while wearing hearing protection you should not be in that environment. Unfortunately, this is not heavily regulated meaning a lot of people still do not wear ear defenders even in the harshest of noises meaning constant damage to the ears.
Viral infections (such as measles or mumps)
Most people are aware of some of the worst effects of viral infections, but not many know it can be a cause of hearing loss. The reason it can affect your hearing is due because the brain can swell which, can damage the cochlear and auditory pathways. In turn, it kills the hair cells meaning a hearing loss will be likely. Although this is more common in infections such as measles and mumps, it does not mean you will definitely get a hearing loss.
Shingles essentially is an issue with the facial nerve. When you get shingles the are many things that happen and it can be very painful. On top of this the hearing system can also be affected meaning a potential hearing loss. Strokes can work very similarly to this.
Ototoxic drugs (medications that damage hearing)
Ototoxic means, to have a toxic effect on the ear. So, any medication or drugs that have ototoxicity can and normally will damage your hearing. This is something to consider discussing with your GP as they should know which one can cause this. Normally, you will find ototoxic properties in: antibiotics such as gentamicin, streptomycin, tobramycin, loop diuretics such as furosemide and platinum-based chemotherapy agents such as cisplatin, carboplatin, and vincristine. Also, a number of nonsteroidal anti-inflammatory can be found to be ototoxic.
This is a disorder that happen in the inner ear. In the cochlear you have three separate compartments. Two of the three compartments have an endolymph fluid and the other has a perilymph fluid. When mixed together these become poisonous to our hearing system. Normally these fluids will never mix, however, some people are not so lucky. What happens, is sometimes there is a weakness in the wall of the cochlear that eventually breaks. When this breaks the two fluids mix. This causes the person to become very sick and dizzy. The person will also experience an imbalance and tinnitus on just one side. Once the episode is over the hearing cells have been poisoned which means they do not work as effectively as before.
Another straight forward reason for hearing loss. Sometimes its just in the genes. If all of the women in the family have a hearing loss and you are the youngest woman. You are likely to develop a hearing loss. This could happen from birth or at any point in your life. If this is you make sure you get your hearing checked regularly.
This is an area most people do not think about. The reason this can result in a hearing loss is due to the amount of blood and oxygen received into the hearing system. If there is excess fat build up in the capillaries there will be less oxygen reaching the hearing system causing a loss. Diabetes will also work in a similar fashion to cause hearing loss. This is also true of smoking and hypertension.
Otherwise known as a vestibular schwannoma. This is a tumour that is attached to the auditory nerve leading to the brain. These are generally very rare. They will stop the hearing from getting to the brain as the tumour grows. It is because as it grows it constricts and squeezes the nerve stopping the signals from getting past. Eventually if left untreated can cause serious complications and death. If caught early enough they can sometimes get rid of this by using a gamma treatment. Otherwise, they will cut the nerve completely meaning a complete hearing loss on one side.
Conductive Hearing Loss
Conductive hearing loss typically works in a different manner it normally involves some sort of obstruction. Conductive losses as a majority are able to be treated and fixed. We have outlined the most common below.
These can be either in the outer ear (canal) or middle ear. The outer ear infections will typically cause a build up of puss. It can cause the ear drum to react differently like hitting a drum under water. While the middle ear infections again tend to have a build up of puss/mucus. This will make the eardrum act differently like hitting a drum full of water. In most cases a simple antibiotic will clear these infections and bring your hearing back to normal.
Perforation or scarring of the eardrum
A perforation is when the eardrum has a hole in it. Perforations usually heal by them selves but can cause the ear drum to scar. If you have a perforation you will not be hearing as well due to the hole. Think about hitting a drum with a big hole in it. Scarring on the eardrum is slightly different. It will normally thicken the eardrum making it less supple and dampening the sound. Most people with scarring on the ear drum will normally not notice the difference.
Very simple yet can have a huge impact. Wax is meant to be in your ear. Period. However, sometimes we can have an overproduction of wax. There is no particular reason as to why this happens, but it is an aggravation. When it does happen, it can cause an up to 40dB loss meaning you will not hear normal speech. It is however, very easy to remove. This can be done by a lot of audiologists or nurses via micro suction or syringing. We always recommend the former as it is much safer.
Dislocation of the middle ear bones
Dislodging the middle ear bones tend to come form an injury to the head. It would normally be due to a fall in older generations. However, it can happen to those involved in sporting injuries and accidents too. It can be fixed in most cases with surgery but depending on the age of the person.
Foreign objects in the ear canal
Children are those that can often end up with foreign objects in their ears. Normally it is because of their inquisitive nature. Others that can end up with objects in the ear, are those who use cotton buds. Sometime the cotton end can fall off leaving it in the canal. Lastly, would be insects, this is less common than the others but can still occur. With the first two it is fairly simple to fix by pulling the object out. Unfortunately, this is not always the case with insects in the ear. It can take a little while for the insect to appear and it may need to be killed before extraction. If the intruder is left in the I may tear through the ear drum and then dislodge the middle ear bones.
Otosclerosis is when the smallest of the three middle ear bones, ‘the stapes’ fuses with the cochlear. This is a fairly common thing in young adults and more so in women. It can occur due to an imbalance of hormones. It is able to be fixed by using a hearing aid or by surgery. The surgery option known as stapedotomy or stapedectomy is where they cut in between the stapes and cochlear to free the movement of the middle ear bones.
The most comment growths you will find are cysts. These can form inside the ear canal, behind the ear or on the lobe. Cysts are thought to appear because of an over production of oil which is unable to be released. They are not normally considered dangerous. Bony tumours otherwise known as exostoses and osteomas are also common in ears. People often refer to this as swimmers’ ear. It has been called swimmers ear because repeated exposure to cold water will increase your chances of getting these. Again, these are not normally seen to be dangerous and, in most cases, don’t cause hearing loss. If, however they do cause a hearing loss they can be surgically removed. Lastly on this list is cholesteatoma. A cholesteatoma is a build up of dead skin cells that form in a sack like structure coming off the ear drum. These tend to be very rare. They are normally managed rather than fixed. They do this by sucking out the dead skin from the sack on a regular basis. However, it can be operated on if absolutely necessary.