TJ Audiology Training

Ear Pathologies and Audiograms: Part 5 Acoustic Neuroma/ Vestibular Schwannoma

Acoustic neuroma/ vestibular schwannoma, are benign usually slow maturing growths, that develop on the vestibulocochlear/ eighth cranial nerve. This nerve leads from the brain to the inner ear. It consists of the vestibular and cochlear nerves.

Acoustic neuromas (AN) develop from Schwann cells, these cells are a type of glial cell, which are non-neuronal cells that support the function of neurons, and wrap around and support nerve fibres. They can occur on any cranial or peripheral nerve in the body, but in the brain, acoustic neuromas are the most common.

Acoustic neuromas typically begin growing where the central nervous system transitions into the peripheral nervous system. The incident rate is somewhere between 1-3 % in 100,000 people and may increase in older age.

Many acoustic neuromas don’t grow, and many that do grow tend to develop slowly. Occasionally they can grow quickly, but this is rarer. Unlike cancer tumours they don’t generally invade and destroy tissue. What can occur is that they cause symptoms as they grow and push on surrounding structures. This may be where you see effects on the face and eye. Medscape: Acoustic Neuroma- Practice Essentials

Symptoms

The symptoms of an acoustic neuroma are as follows:

Unilateral/asymmetrical hearing loss is the most common symptom that leads a client to attend an audiology appointment. Usually progressive
Tinnitus – Especially if it is unilateral, non-pulsatile
Vertigo and disequilibrium – Uncommon (may come and go) as the tumour grows it may cause dizziness and then the brain habituates and compensates to the change and the dizziness is less.
Headaches – Present in 50-60% of patients at the time of diagnosis
Facial numbness – Occurs in about 25% of patients
Some acoustic neuromas can present as a sudden (idiopathic) hearing loss (this actually happened to a relative of mine). It’s a less typical presentation but it does occur.

Generally, acoustic neuromas cause ear symptoms on one ear only. For example, the individual may suffer with a sensorineural hearing loss or unilateral tinnitus on one side. Although the tumour usually develops on component of the vestibular nerve, vertigo from it is less common for the reasons I mentioned above. Although the facial nerve is also in the internal auditory meatus, an acoustic neuroma causing facial weakness is not as common as hearing loss or tinnitus. This is because motor nerve fibres around the face are resistant to pressure. Whereas the hearing fibres are thin and more likely to be damaged by pressure.

Diagram and symptoms behaviours from : Medscape: Acoustic Neuroma- Practice Essentials

Referral Criteria

Don’t forget unilateral tinnitus or an unexplained increase in tinnitus in the last 6 months as well.

Audiograms Examples

Below are example audiograms for acoustic neuromas (AN) Remember these are examples and there will be variations in audiometric presentation for example where there is already an age-related hearing loss present, this is why you should always look at the onwards referral guidelines for post audiometry to see if the client meets the criteria for either asymmetry or deterioration.

Example 1: Could be an example of an early found AN

Example 2 :Could be on an AN found with a worse hearing loss or watch and wait, where there may have been some progression in hearing loss

Example 3: AN on right ear with age related loss

Speech Testing

Please note that speech testing can also indicate the possibility of an AN present. ‘Roll over’ is often found in clients with AN’s. ‘Roll over’ is when speech sounds are presented at levels where the client should hear well and respond with a good score but instead as the words are presented at louder levels the percentage correct lessens

‘Roll-over’ and is calculated by the following equation:

Roll-over index = (maximum score minus minimum score) divided by maximum score

If roll-over is detected at a certain value (the value is dependent on the word list chosen for testing but is commonly larger than 0.4/0.45 AB word list as an example), then it is considered to be a sign of retro-cochlear pathology. If you look at the graph below the Y axis shows percentage correct and the X access the loudness as you can see for an AN as the sound is made louder there is a drop off in percentage correct rather than a plateau as there is for normal ears, conductive and cochlear loss hearing losses. Speech Audiometry PDF University of Cape Town

Intervention Options

Acoustic neuromas are generally managed in one of the following 3 ways. Which is chosen is dependent on the size and placement of the tumour, the clients/patient’s choices and recommendations by the ENT surgeon:

Watch and wait observation/monitoring with or without hearing aids (this will include ongoing MRI’s to check growth and notification of any changes in symptoms or growth shown on MRI to ENT) This is done more frequently in the below populations

Elderly patients
Patients with small tumours, especially if their hearing is good
Patients with medical conditions that significantly increase the risk from an operation
Patients who refuse treatment
Patients with a tumour on the side of an only hearing ear

Stereotactic radiotherapy uses radiation delivered to a precise point or series of points in order to maximize the amount of radiation delivered to the acoustic neuroma tissue while minimizing the exposure of normal tissues nearby. It is commonly delivered as a single dose or less commonly, as multiple smaller doses. The goal is to stop tumour growth. People will need to be monitored with MRI scans after treatment to assess for any changes in size. In the UK we call this gamma knife and people often have to travel (referred to other centres) for this option.

Surgical removal is another treatment of for AN removal. The surgery can be conducted in different ways to remove the AN. How they approach the surgical removal of the AN depends on the location, size, hearing and facial nerve status as to which way is the best to access it. It is not unusual for surgery to involve Neurosurgeons along with the Ear, Nose and Throat Surgeons

Ear Pathologies and Audiograms Part 4: Meniere’s Disease

For this blog we will be looking at Meniere’s disease. Remember audiograms will differ depending where they are along the pathology pathway. Meniere’s causes a progressive hearing loss in sufferers. I will try and give examples of audiograms early on the disease pathway and later on when the hearing loss has progressed. Once again these are examples, of audiograms taken from clients. Meniere’s disease is very individualistic and the how the different symptoms present and how they affect the sufferer will vary from individual to individual. Because of how complicated Meniere’s can be this will be a very long blog!

Meniere’s

According to the American National Institute on Deafness and Other Communication Disorders ‘Meniere’s disease is a disorder of the inner ear that causes severe dizziness (vertigo), ringing in the ears (tinnitus), hearing loss, and a feeling of fullness or congestion in the ear. Meniere’s disease usually affects only one ear, but in 15% to 25% of people with the disorder, both ears may be affected. Attacks of dizziness may come on suddenly or after a short period of tinnitus or muffled hearing. Some people have single attacks of dizziness separated by long periods of time. Others may experience many attacks close together over several days. Some people with Ménière’s disease have vertigo so extreme that they lose their balance and fall’. https://www.nidcd.nih.gov/health/menieres-disease (I have even seen cases where the individual is unable to get out of bed and function normally, the vertigo is so persistent and severe).

We rarely see it in individuals under 18 years of age. It is most likely to occur in adults between the ages of 40-60 years of age. No one is quite sure what causes Meniere’s disease. Where it occurs in more than one family member it is thought genetic variations may play a part in the origin. About 7-10% of those affected have a family history of the condition. Incidence of Meniere’s is between 1:1000 and 1:2000 of the population. (Meniere’s UK)

What happens in the ear

When you see a picture of the cochlear you will see that it contains a snail like bit called the cochlea and two upwards facing semi-circular canals these are the organs of balance NIDCD explains it as follows ‘(the semi circular canals and otolithic organs) and the cochlea and has two sections: the bony labyrinth and the membranous labyrinth. The membranous labyrinth is filled with a fluid called endolymph that stimulates receptors in the balance organs as the body moves. The receptors then send signals to the brain about the body’s position and movement. In the cochlea, the fluid is compressed in response to sound vibrations. This stimulates sensory cells that send signals to the brain. In people with Meniere’s disease, a build up of endolymph in the labyrinth called endolymphatic hydrops disrupts normal balance and hearing signals between the inner ear and the brain. This disruption is also associated with vertigo and other Meniere’s disease symptoms’ https://www.nidcd.nih.gov/health/menieres-disease.

We think this endolymphatic hydrops causes an increase in the pressure in the endolymphatic space. It is quite likely that this increased pressure is what causes the fullness and reduced hearing. Meniere’s UK explains it quite nicely ‘The sudden release in pressure accounts for the sudden attacks of vertigo. Repeated episodes of high pressure and sudden releases of that pressure damage the delicate structures of the inner ear and the balance structures of the semi-circular canals. This cumulative damage results in a decline in hearing levels over time.’

Symptoms of Meniere’s

Meniere’s is very individualistic; symptoms vary between people and over time. The main symptom is attacks of vertigo with nausea and vomiting. These attacks can last from a few minutes to 24 hours (or longer in some people). During the attack people may also suffer from tinnitus, a feeling of fullness in the affected ear and hearing loss. After the attack the hearing may improve, but generally never to where it was previously. The tinnitus and fullness may go.

For some tinnitus is there all the time with Meniere’s but worsens during the attack. As Meniere’s disease effects the low frequencies initially, many sufferers indicate that the tinnitus sound is often more low frequency in pitch like a rumbling.

Periods of remission between attacks can vary from days to months or even years. For some the vertigo attacks can be severely debilitating causing them to be bed bound; as just raising their head will make the dizziness worse and induce nausea and vomiting. Whilst other individuals may be less affected. As it progresses the vertigo may become less severe. In the later stages tinnitus is often more prominent and the fluctuating hearing loss worsens. Some individuals with Meniere’s will not just have a significant hearing loss but also find that what they are hearing, even with hearing aids in, is severally distorted and may also suffer from sound tolerance issues whilst others may not have this issue at all.

Some people use some of these symptoms as forewarning as to when an attack is about to occur. I have had many clients over the years say that a sudden change in the ear fullness or increase in the tinnitus alerts them to the fact that an attack is imminent.

Lastly whilst stress is not a trigger to Meniere’s we know that it can increase the frequency and intensity of attacks.

Diagnosing Meniere’s disease

GPs cannot diagnose Meniere’s disease. Only Ear, Nose and Throat Surgeons/Otolaryngologists are able to diagnose the disorder after evaluating all the information from testing and medical history. There is no one test that allows for diagnosis. The client’s history, hearing tests, speech understanding tests, blood tests, MRI scans and vestibular testing procedures which check the balance mechanism will be used in order to get a diagnosis. For further information on these visit Visiting ENT, diagnosis and testing | Ménière’s Society

Intervention Options

Hearing Aids

Hearing aids can be helpful for suffers, and many will find it improves their hearing. However, the sufferer needs to have a clear understanding of the limitations also. Speech in noise understanding will still be difficult, and hearing aids will need to be adjusted as the hearing loss changes and in the later stages, discrimination becomes further impeded. You may wish to consider a CROS aid for the affected Meniere’s ear, particularly in the mid to late stages of the disease. For those with hyperacusis issues or severe distortion then hearing aids may be very limited in their benefit or may not work at all for that ear. Hearing aids may also help with the tinnitus. (remember tinnitus therapy is also available on the NHS if this is needed). I would always suggest trying a hearing aid, but both of you must have a clear understanding and discussion about the limitations and benefits and the issues that may occur.

Surgery

Where the balance/vertigo is severely affecting the client’s quality of life is then surgical intervention may be the only option. There are different options here such as intratympanic injections and endolymphatic sac surgery. Surgery | Ménière’s Society

Drugs/Therapy

Medications can be used to help manage vertigo symptoms Medication | Ménière’s Society. Some people also find adjusting their diet and reducing their salt intake helps with symptoms. Also managing stress is very important in helping control the symptoms. Controlling Your_Symptoms_(Nov_2023).pdf. There are also balance rehabilitation exercises that help you manage your symptoms Balancing_Retraining_(Nov_2023).pdf

Audiograms

The “classic” picture of Meniere’s hearing loss is that there is a fluctuating, gradually progressive sensorineural hearing loss. It starts with low frequency hearing loss, and eventually progresses to become “peaked” (both low and high tone), and then flat. Audiograms and description from Hearing loss in Meniere’s disease

Early Meniere’s Disease Left ear : Low Freq are reduced

Mid stage Meniere’s Disease Right Ear: Low Freq worse but flattening out

Late-stage Meniere’s Disease Right ear: Hearing aid likely to be ineffective CROS/BICROS better option

Ear Pathologies and Audiograms Part 3 Otosclerosis

We are onto Part 3 already. This next block will be looking at possible audiograms for pathologies such as Otosclerosis, Meniere’s disease, ototoxic medication etc. Remember audiograms will differ depending where they are along the pathology pathway. Writing this I realised there is too much information to give on each topic; so, we will keep to one pathology for each of the upcoming blogs. As often these losses are progressive, I will try examples of early on the disease pathway and later on when the loss has progressed. Otosclerosis – FRCS ENT Exam Essentials is a video format that also helps explain the below.

Otosclerosis

Bone tissue in the body renews itself by replacing old tissue with new. In Otosclerosis regularly re-laid spongy bone, hardens abnormally and leads to fixation and this impairs the movement of the bone; most commonly the stapes. This affects the conduction of sound from the middle ear to the cochlea, causing a conductive hearing loss. Over 50% of people with otosclerosis, have a family history of the condition. Is an autosomal dominant mode of inheritance. Prevalence in women is twice that of men. We know that pregnancy can worsen the condition (we have yet to understand clearly why). We mostly see it in people of European origin, in people of Asian origin it is less common and even less so in people of African descent. Otosclerosis – StatPearls – NCBI Bookshelf. (Information for your client-Otosclerosis and Stapedotomy | ENT UK)

They will have the following presentation.

Gradual decline in hearing usually seen to start in people in their 20-30’s however it is the most noticeable in their 30’s. It can start as early as 11 yrs of age to 45 yrs old. (earlier presentation in individuals with a family history)
Conductive hearing loss with Carhart’s notch at 2KHz.
Usually starts in one ear and then moves to the other. This loss may appear very gradually. Many people with otosclerosis first notice that they are unable to hear low-pitched sounds or can’t hear a whisper. Some people may also experience dizziness, balance problems, or tinnitus.
Excellent speech discrimination scores (even with cochlear otosclerosis)
Tympanometry wise, normal middle ear pressure and ear canal volume, static compliance is either normal or shows stiffness (0.3 or under)
Absence of middle ear reflexes.
Worsens with pregnancy/ is often first noticed during pregnancy
Menopause, trauma, surgery have also been noted as aggravators of otosclerosis

Audiogram, Otosclerosis. An audiogram showing bilateral mixed hearing loss in a patient with otosclerosis. The typical dip in bone conduction is also present.

Above you will see a dip at 2000hz we call this a Cahart’s notch. This is a mechanical artifact of testing, rather than being a true sensorineural hearing loss. The normal ossicular resonance in humans is around 2000 Hz, which is impaired by stapes fixation. If the client has surgery this notch may disappear.

This is quite different to an audiogram for otitis media

Dr Chris de Souza ENT Specialist Audiological Investigation of Otosclerosis gives the below great explanation of the disease pathway for a client with otosclerosis

Early stages

In the early stages of otosclerosis, audiograms show a conductive hearing loss.

Late stages

As the disease progresses, the hearing loss worsens in the high frequencies and the air-bone gap widens. The audiogram changes from an upward sloping pattern to a flat pattern.

Cochlear involvement

If the disease extends into the cochlea, a sensorineural hearing loss can develop. This is called cochlear otosclerosis.

This is an example on the right of advanced otosclerosis and is post stapes surgery

Intervention Options

Watch and Wait

People progress differently, so in some cases it is a watch and wait. Interesting to note that in women it may decline quicker with each subsequent pregnancy.

Hearing Aids

If there is a loss that can be aided then hearing aids will work well as it is a conduction of sound issue. This may also be the preferred treatment over surgery if the individual has another pathology on the other ear, such as an Acoustic Neuroma or Meniere’s. I have in the past indicated to my clients when progression of the otosclerosis is occurring (sensorineural component is progressing) and they may be getting to the stage where medical intervention will be less effective. This allows them to choose between staying with a hearing aid or going for surgery.

Surgery

The current standard medical treatment is a stapedectomy. A prosthesis is put in to replace the damaged bone. By removing the diseased bone and replacing it with a prosthesis this will allow the vibration of sound in the middle to work effectively again.

Patients with far advanced otosclerosis as discussed in the hearing aid section, and severe hearing loss, can still benefit from stapedectomy surgery but they will still need to use a hearing aid (as shown in the audiogram above). Otosclerosis – Vestibular Disorders Association

Ear Pathologies and Audiograms Part 2 – On the Soap Box

What a strange title to give to part 2 of this series! I have used this title as they are the audiograms that I talk about often, that people either miss or mistake for something else. In all cases except for some of the malingers it led to unnecessary emotional stress for the client’s involved.

Collapsed Ear Canals

Tracy who started TJ Audiology Training and no doubt many others, say that I harp on about this incessantly, and I am happy to admit I do! I think it is a real issue that we miss far too often. One research study on over 300 individuals aged between 3-97 years found that ear canal collapse was observed in 11.4% of their subjects. Prevalence ranged from 6.3% to 36.6%. With the higher percentage score being for the over 75’s. More males than females they found had the problem.

So why is this such an issue for audiograms? Canal collapse will mimic a conductive or a mixed loss. This can then lead to unnecessary ENT appointments and investigations, when all along it was a collapsed canal. This makes us as audiologists look bad if we haven’t seen it. It’s is in some cases an unnecessary referral/cost for MRI’s and ENT time. Even more importantly the personal stress to the client, who is now being investigated for a potential ear pathology cannot be underestimated.

Let’s, talk about how to check for it. Firstly, when we do otoscopy, and you are looking behind the pinna, look also at the opening to the ear canal. Is it narrow? If it is press on the middle part of the pinna. If the canal narrows, you potentially have a collapsed canal.

Client history may also be a dead giveaway! Clients, with collapsed canal will often complain that ear buds don’t stay in or are uncomfortable or they have to use the smallest ear bud. Some will even notice if they press the phone to their ear, they hear worse.

What happens during an audiogram with a collapsed ear canal?

The pressure from the earphone can partially or fully close the ear canal
This can cause increased hearing thresholds, especially at high frequencies
The results can mimic other conditions, like noise-induced hearing loss
Client hears you better than their audiogram would suggest.
If the client already has hearing aids, they will often complain the hearing aids are too loud and/or occluding, and come back for numerous adjustments and the settings of the aids will end up being under target.
They will often have normal tymps despite the conductive loss.

Example 1

Example 2

Above are 2 example audiograms. You can see how in case 1 the higher frequencies have been affected (from Collapsed Ear Canal and Sudden Sensorineural Hearing loss) In case 2 which was a severe canal collapse, it has affected all frequencies. Case 2 is exactly one of those cases where multiple investigations occurred before they realised the issue. (from Bilateral Conductive Hearing Loss due to Collapsed Ear Canals in a 35 Years Old Female – MedCrave online).

As we have said previously mass (a canal collapsing over itself) will affect the higher frequencies which is why we see in case 1, the higher frequencies are down. If masked bone had been done on the supra-aural audiogram there would have been an air bone gap. The audiologist in this case realised it was a collapsed canal and then used inserts hence why there is no masking or BC.

In case 2 it’s a complete collapse causing both stiffness and mass and hence why there is an airbone gap across all frequencies. However, it is worse in the higher frequencies this is another clue!

In both cases tympanometry results were showing normal middle ear movement.

What to do if you don’t have inserts?

Not everywhere has inserts. Some people have used speculum to hold the canal open and then put headphones on top. This can be uncomfortable. I have found using tympanometry tips work best (as big as is comfortable). Cut off the flange part of the tymp tip, tie cotton string through it and knot it; and then insert. The cotton string makes taking it out so much easier. Always note on your audiograms that you have found collapsed canals. This ensures that all individuals attending to this client now and in the future are aware of the issue.

Let’s fool you audiogram

This audiogram occurred when I was working in the NHS. Whilst it is possible that the loss occurred post operatively. I find that unlikely as the previous audiograms hinted the underlying loss.

As it was a child people suspected it was due to slight inattention/boredom during a hearing test (the child was under 7). As you can see pre-operation both sides have a conductive loss. However, the right side is showing a mixed loss at 2000Hz. Staff though this was a false positive. Look at the audiogram below though, there is a hint that this may be sensorineural, even if the BC is incorrect. Why is the AC dip so much worse than the adjacent frequencies at 2000hz on the right? Tymps were flat in this case.

Pre-operative

Post operative

I strongly suspected that I would get the above audiogram as the 2 previous audiograms had shown the dip in AC & BC at 2000Hz to varying degrees. The dip at 2000Hz is out of proportion to the other frequencies around it, yes it can be fake if it isn’t repeatable to some degree. Given that the dip, stayed in all prior audiograms should have alerted to all that there was potentially an underlying sensorineural hearing loss at 2000Hz on the right. The child reported much better hearing post operatively but still some issues in noise. Needless to say, it was a shock to both the mother and the child. This result did not change post grommets falling out or in later tests. Unfortunately, I wasn’t able to find out the probable cause of the sensorineural dip at this frequency.

I always say if it doesn’t look right, it isn’t right. This dip at 2000Hz was consistent. It is rare for people to fake the similar levels of an audiogram well over a series of hearing tests.

The malinger!

Malingering means not giving a true result. There are many different reasons for this. It could be due to attention seeking, psychological issues, misunderstanding instructions, or wanting compensation for their hearing loss. Jerger, in 1981 came up with the below statistics, in brackets are my suggested reasons.

2% of population
7% in children age 6-17 years
Typical mean onset of NOHL = 10-12 years (school stress, sibling has hearing loss)
Rare below 7 years of age (as children under this age seek approval)
Up to 50% of those seeking compensation

So, what type of audiograms would you see?

Observation

PTA response pattern
Audiometric pattern – e.g. flat SNHL or worse than subjective hearing level
Between ear unmasked level difference greater than 70 dB for AC and 10-20 dB for BC
History – a lot can be gained by listening to the patient e.g. sibling with hearing loss, exams coming up, trauma.

The above audiogram’s AC thresholds on the right were not yet masked. Therefore, this a malingering audiogram. This is because it isn’t possible for there to be more than a 70dB difference between ears without the good ear (left) helping the bad ear. Therefore, we would expect better AC results on the right pre masking than what we are given above. True hearing test results on the right would be better around 60-70dB and deteriorate when rule 1 of masking is applied (more than 40db difference between AC thresholds). Also why is the BC so good particularly if there is no history that suggests conductive loss.

This is an easy one to spot. However, taking a verbal history with a client tells a lot. For example, if you a getting a moderate to severe sensorineural hearing loss but they can still hear you speak with no hearing aids when you turn away, well that isn’t possible!

Also flatter audiograms are easier to fake than a sloping loss. So we see these more with malingering audiograms.

Remember the above audiograms are examples, variations to these will occur given clients otological history. But hopefully I have given you a good place to start.

Coming soon: Part 3 – Middle ear pathologies such as otosclerosis

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Ear Pathologies and Audiograms: Part 1 (Frequent Offenders)

Our BSA Audiometry course is a great place to start when you wish to learn how to do a basic audiogram. For those of you that are training to be an audiologist then we offer a masking course too. Please look at our training calendar for dates for these Training Calendar – TJ Audiology Training. We will soon be offering masking theory as an online tutorial, through a portal accessed from our webpage (watch this space)

So, you understand how to do an audiogram but what do the results mean? What are they telling me? When I started audiology 30 years ago, we had a great text book by James Jerger called Clinical Audiology (easier to read than Katz!!) that gave you both audiograms and tympanograms for different types of hearing loss and this helped give you a starting point. Its long out of print now. However, we still regularly use his classifications for our tympanograms.

I am not going to explain an audiogram graph and the different symbols (AC: Air Conduction and BC: Bone Conduction) and degrees of loss, I am assuming that you already have this knowledge! Let’s, start simple and then get more complex (because there is so much information to give this will be an ongoing series). Remember the list is not exhaustive and you will get people that don’t fit the normal pattern. This is why the BAA Onward referral guidance – British Academy of Audiology |British Academy of Audiology has red flags for referral onto ENT, include other audiological issues such as dizziness, tinnitus and facial palsy, not just the audiogram.

Normal Hearing

Please note if hearing is normal but there are other red flags such as dizziness or unilateral or pulsatile tinnitus onwards referral will be required (if these red flags are present for any of the hearing loss below then onwards referral to ENT will still be needed). You would generally expect normal tympanometry results.

Sensorineural Hearing Loss

Sensorineural. The triangles which are the bone conduction results are within 10dB of the air conduction thresholds indicating that this is a mild to moderate sensorineural hearing loss. You would generally expect normal tymps with this loss.

Noise Induced Hearing Loss

With a noise induced loss you will see a dip between 3-6kHz and then upwards improvement and the BC results within 10dB of the AC (only AC shown on these examples). However, as a client ages, then you add an age-related loss on top or increasing noise exposure (as shown in the 2nd graph) then the proportions will change. You would generally expect normal tymps.

Glue Ear

Glue ear is often found in children under the age of 7-9. The eustachian tube is narrower and flatter than in an adult. Children under this age are more likely to suffer from Glue ear/Otitis Media as the eustachian tube is unable to drain as effectively.

The audiogram with show reduced hearing through the headphones (AC), but the bone conduction results (BC) will be within the normal range. (20db or less if there is no underlying sensorineural hearing loss). You will either have a flat tymp or negative middle ear pressure for the reasons explained below.

The audiogram gives a flatter presentation when the middle ear is so fluid filled that both mass (how much mass is there in an object) and stiffness (how stiff the object is) are being affected. Stiffness affects the lower frequencies and mass the higher frequencies. If there was some draining or improvement in the glue ear than you would see the higher frequencies improve. (as there is now less mass). (31) Acute Otitis Media – FRCS ENT Exam Essentials – YouTube explains otitis media. For information sheets please see Glue Ear – Otitis Media with Effusion (OME) | ENT UK

Tympanosclerosis

Tympanosclerosis is scaring on the eardrum. The scarring occurs either from perforations that have healed or from having had grommets. The amount of scarring will be dependent on the amount of irritation and bleeding that has occurred during these events. Scarring will cause the eardrum’s movement to be stiffer. Stiffness as we said earlier will affect the lower frequencies as shown in the audiogram. Tymps may show restricted or shallow movement.

Perforation

Remember this is an example audiogram and your audiograms may differ . In this case the client already has an underlying sensorineural hearing loss (the BC is out of the normal range). The degree of conductive component of the loss will be dependent on how the perforation affects the transmission of sound from the middle ear space to the cochlea. As for tympanometry you will have either a flat tymp with a large canal volume or you will not be able to obtain a seal. Below is another audiogram example for a perforation where the squiggly lines (masked BC are within normal and the AC is down).

Collapsed Ear Canals : Making Earmoulds

Collapsed Ear Canals: Earmould impressions and hearing aid issues

Collapsed ear canals can be problematical when it comes to getting a well-fitting ear mould. The canal can neither be too long or too short. If either, then the earmould will be pushed out of the canal with jaw movement. A study in Brazil from 2017 suggested it occurs in on an average in 11% of clients. Statistically, they found it was between 3% – 36% across age groups with the largest percentage in individuals 75+ . Males are more likely to suffer from canal collapse. Ear canal collapse prevalence & associated factors among users of a centre of prevention and rehabilitation for disabilities

So how do you know if the ear canal is collapsing ? As shown in the 2^nd image above.

Firstly, when doing otoscopy, we always look behind the ear for scars. Then we look straight into the canal. Often without first truly observing the canal and concha. I always tell my students to put some light pressure on the pinna to look to see if the ear canal is still remaining open. A collapsing canal will close further with just a little pressure, it will become a very narrow slit. You then know you have a collapsed canal.

Clients with collapsed canals may be more prone to wax accumulation (as it can’t exit the ear easily) but more importantly they may have issues with keeping hearing aids in their ears.

Open Fits/ Receiver-In-The Ear fittings with collapsing canals?

The client may be new to hearing aids and they wish to try an Open Fit or Receiver-In-The Ear with a dome; if their hearing loss allows. Or they already have hearing aids and prefer this option to an earmould. All you can both do is try and see if this works.

Be aware that you will need to have a trailing arm/tail on the wire to ensure that the wire and dome don’t push themselves out when the client speaks. See below image of what this tail looks like. I always say to these clients that this type of fitting may not work and you may need an earmould if we find it keeps pushing itself out. (This saves them having unrealistic expectations and getting upset when things don’t work)

So, they need an earmould … What advice would I give you?

When it comes to everyday impressions most earmould manufacturers preferred a closed jaw impression (the client doesn’t talk or move their jaw whilst the impression is setting).

This is fine when the client has a normal shaped canal or their canals are not highly mobile. However, as Ahead Simulations chart Earmold Impressions – AHead Simulations shows below you should always consider doing open jaw impressions if you have any of the below issues.

It is strongly advisable to take on open jaw impression for ears with collapsed canals, or highly mobile canals. In fact, I would suggest where you are up to your 3^rd remake, comfort has been an issue or you know the canal is very mobile, then make both open and closed jaw impressions. Then the manufacturer can compare the two.

Also THINK! I made the mistake once of making sleep plugs for a client and not realising that she wore a mouth guard when sleeping. The sleep plugs didn’t work at all! I then made an open jaw impression which was consistent more with the shape of her canal when the mouth guard was in and hey presto it was a good fit! (she brought her mouth guard in to the 2nd appointment)

If the client wants a canal mould for a collapse canal, then the mould requires an anchoring point like a claw/spur as shown below.

How do I take an open jaw impression?

In order to take an open-jaw impression, a client opens their mouth wide using a bite bar before the impression material is injected. Keeps the bite bar in their mouth and this is not taken out till the impression material is fully cured.

A mouth prop can be bought from Impression Bite (25 Pack) – Puretone Shop

The recommended method according to the British Society of Audiology (BSA) is to insert the prop lengthwise in the corner of the mouth at the side the impression is taken as shown above. ‘For this process a dental mouth prop or bite-block should be placed between the subject’s side or rear teeth, after the otostop is inserted. (Reproduced with permission of Starkey Laboratories) A new and clean mouth prop should be used for each subject. The position of the otostop should be checked carefully using an otoscope when the mouth prop is in place to ensure there are no gaps between the otostop and the canal walls. The subject should be given a tissue to deal with any dribbling when the mouth prop is in place. Once the impression is set the mouth prop should be removed first. As the impression is likely to be a tight fit, extra care is required to ensure it is removed safely. With an open jaw it is particularly helpful if the subject moves their jaw gently from side to side during its removal’. (BSA Recommended Procedure 2023 Aural Impression Taking)

What next?

It may be a good idea to also make a closed jaw impression as well so the mould manufacturer can compare the two. Some people also do talking/moving jaw impressions, the thought is that the shape of the canal will be somewhere in between the two and give a more truthful impression of the ear canal.

At the moment it isn’t enough evidence to indicate whether there is a benefit to talking impressions over open jaw, so we are best to stay with the BSA recommendation of doing open jaw.

Basically, the rule of thumb is if they have had issues getting good moulds in the past, have collapsed canals or flatten conchae, or they have overly mobile canals (can check when doing otoscopy or they may have jaw issues that they have told you about) then do an open jaw impression.

Let the mould manufacturer know that is an open jaw impression, write as much information on the impression sticker to let them know of the issues (they don’t have a crystal ball) and then send on, and hopefully you should get a good earmould back that your client is happy with.

Lastly……

At some point soon will be a blog from me on canal collapse and the audiogram. I honestly believe this is an issue that is far too often missed by audiologists and audiometricians, resulting in clients being unnecessarily referred (and embarrassingly so) onto Ear, Nose and Throat Surgeons. Be prepared….. as I will definitely be on the soap box screaming on this subject!

OTITIS EXTERNA

As you know Wax Removal is now one of the courses we run at TJ Audiology Training. This blog is about what Otitis Externa is; how to spot the signs and what to do, if you are removing wax, about to take an impression or to do a hearing test.

What is otitis externa? Firstly, it’s in the name Otitis is Latin for ear and Externa is external ear and it is an inflammation/infection of that area (generally it just the ear canal). Some people call it swimmers’ ear. But be aware this can mean something different depending on the region you live in the UK or what country you are in.

What causes Otitis Externa?

We aren’t exactly sure but some of the possible causes are:

Damage to the skin in the ear canal (caused by cotton buds, scratching or poking) can cause inflammation and infection.
Water can get into the ear canal during swimming. The stagnant water triggers an infection (Remember all water contains pseudomonas bacteria) . This often happens if there is a lot of wax and the water gets stuck behind the wax.
Hot, humid weather makes inflammation of the ear canal more likely to develop.
Skin conditions such as eczema, or psoriasis, can make someone more likely to get problems with the ear canal.
Diabetes, radiotherapy (near the ear) and immune and conditions that effect the immune system can also make the client more prone to infection

How to spot the signs?

In general the first sign your client will complain of is persistent itchiness and dry flaky skin around he canal and their may be some redness too.
Smell – this like off cheese or smelly socks (it stays with you when you smell it!)
A watery discharge from the ear canal (this can change later when its whiter)
Discomfort moving the jaw when chewing or speaking.
The ear canal starting to close up due to swelling and inflammation.
Reduced hearing due to the canal being full of discharge or the canal is completely swollen
Fungal spores are also a form of otitis externa. These will be either white and furry or black (see picture below)

What should you do as an ear care professional?

Firstly, if they are seeing you for ear impressions or a hearing test, then you need to send them away. The swollen canal will prevent an accurate impression and you can’t do a hearing test as the risk of cross infection is too high.

What if they are seeing you for wax removal?

It may be that you can’t see it or smell it till you have removed some wax. If this is the case then remove as much as you can comfortably for the client. This will give any intervention a better chance of working, as you have made the canal clear of as much debris and discharge for antibiotics to work on the skin. Remember the ear may be sore so you may have to work slowly and gently and you not be able to remove all of it. (Please note irrigation is not an option here only microsuction; as water from irrigation will make things worse).

Remind them of good aural hygiene. No water near the ears and no touching of the ears whatsoever.

Once you have removed the wax and discharge, refer the client to the GP. They may prescribe eardrops or spray. Often, it’s a combination of an antibiotic to treat any infection, and a steroid to reduce the inflammation and itching. The treatment usually lasts for 7 to 10 days. They need to follow the prescribed course. If they return to you because the treatment hasn’t worked, then you need to recommend that the nurse or GP take a swab sample, as the antibiotics may be the wrong type for the bacteria present. To understand the prescribing pathway otitis-externa-acute-and-chronic.pdf (Edit 9.1.25)from Nottinghamshire Area Prescribing Committee is a very helpful document.

Edit 9.1.25 Outer ear infection or otitis externa ENT UK is a useful sheet to give to clients.

Lastly

If the canal is swollen shut and the pinna and the concha are also swollen then the otitis externa has developed into cellulitis, this is a rare occurrence/side effect . (This may have occurred due to the client scratching the already infected ear and adding another bacteria). They will require intravenous antibiotics for this, so in this case suggest they attend A+E as this cannot be given at a GP surgery.

Cochlear Anatomy

Personally my mind boggles when it comes to this subject. Cochlear anatomy is amazing and the cochlear itself is so tiny only 36mm in length and yet it does so much. Whilst there are many good explanations out there, anatomist Dr Sam Webster description from Swansea University is one of my favourites. Watch his video below for more information on cochlear anatomy. Be prepared to get a cup of coffee or tea and set 30 minutes aside to watch his explanation!

Whats new with TJ Audiology Training

Its been a long while since we have posted a blog!!!!!!!!

TJ Audiology Training as you may have noticed has changed its name ever so slightly and we now have a new a fantastic new logo. Watch this space for new developments in the next 6-12 months. Like our new wax course Ear Wax Removal/ Aural Care Course

We will be running the wax removal course again on 22nd -23rd January 2025; with volunteer human ears to practice on too! Our students loved the September course which we ran using equipment from Puretone so please get in touch if you would like to know more.

Otis – Audiometry training with virtual patients

Otis the virtual patient (from Innoforce.com) can be use to practice basic audiometry and tympanometry and masking.

We use it in our classes as it is a great way of developing your skills in audiometry without having the pressure of the time or the client’s ability to focus, while getting used to the controls and techniques required. If you’re learning how to carry out masking, it is an invaluable learning and evaluation tool and your don’t need to rely on your supervisor to explain results.

Otis is a little bit like a real person, for example, your client can fall asleep if you take too long or shout if you present sounds that are too loud. You can view your otoscopy, history and tymp data as part of the assessment. There is reference data for masking and symbols.

You have real time evaluation and assessment of your procedure as you do the audiometry – it tracks your accuracy, time and errors. You can also progress from easier audiograms, to more difficult cases.

The structure and function of the ear and its role in hearing and balance

Although the ear is small in size, it is essential for hearing and balance, and problems of the ear can be linked to other conditions. Understanding the structure and function of the ear will help us to pick up problems early and improve the care of patients with ear problems.

Here’s a very helpful article published in the Nursing Times which explains about the ear and its role in hearing.

Images of the ear

Dr. Hawke is a Professor Emeritus, Department of Otolaryngology-Head and Neck Surgery at the University of Toronto. He is known both for his basic and clinical research in diseases of the ear and sinuses. He has travelled the world extensively as an Invited Professor delivering countless lectures and seminars.

He is one of the pioneers in medical photography. His images are captured using telescopic techniques that he also helped pioneer.

We recommend that you look at his documents on the diseases of the ear as they are incredibly useful.

Michael Saunders is a UK based ENT. His images of the ear canal and drum can be found on the ENT Bristol website along with very helpful descriptions.

Dr. Terry W. Owens was a board certified ENT specialist. He describes how to examine the ear, many common ear problems, what to look for, laboratory tests, common treatments and possible prevention. The text is clear, simple and with minimal technical medical terminology. Here is a link to his photobook which will help you to understand ear diseases.