News & Reviews

It’s just a mild hearing loss…

Posted 11th June 2018 by Adam Chell

A review of clinical practice in relation to mild hearing loss

I recently saw an individual in my clinic. They attended on their own for a free ear health check. They described how they had difficulties hearing in background noise and it had impacted enough on their quality of life to consider having their hearing tested.

mild hearing loss

You have a mild hearing loss

I explained to the client that they have a mild hearing loss in both ears. Their response was, ‘oh, that’s not too bad then’. I then advised that given the difficulties described and the mild hearing loss presented it may or may not be beneficial to trial a hearing aid. The individual decided not to proceed with a trial of a hearing aid and instead will monitor their hearing annually. It got me thinking, ‘Would my approach or their reaction be different if I didn’t classify their hearing loss as mild?’

On reflection, I was very reserved in my recommendation, almost casual. My fear was, ‘Am I making the right decision?’. The reason I had this doubt is because I’m an independent audiologist. For people to go ahead with hearing aids from me, they would need to make a financial investment.

Commercial sensitivity is a strange thing and a high level of trust is required between the patient and the clinician. If I was to advise that, ‘Yes, you have hearing loss and would benefit from a hearing aid’, they may then get a second opinion from the NHS or elsewhere. The advice from them may be that they have a mild hearing loss (just like I did) and that doesn’t require intervention. This may impact negatively on their opinion of me as a clinician and they would be unlikely to return.

This thought may seem unreasonable, but it was only last year North Staffordshire NHS trust made the decision to cut hearing aid provision for individuals with mild hearing loss. What message does that send to the population? That their hearing loss is nothing to worry about?

I was left mulling over this appointment. In the interest of self-improvement I decided to get advice from my LinkedIn network. I’m glad I did. The discussion I had with my peers was enlightening. From the information exchanged, specifically by Priya Singh of Kent Hearing, UK and Marjolijn Kindt, Sivantos Group ANZ, I read deeper on hidden hearing loss, and auditory deprivation.

Auditory Deprivation

In 2017, Glick and Sharma1 published their review on auditory deprivation, or more specifically the effect of hearing loss on cross-modal plasticity in developmental and age-related hearing loss. I had to read the abstract a couple of times to get my head around the language. I will try to portray it in a way that I now understand.

If you have a hearing loss the brain changes. The brain recognises that the quality of information from the ears has deteriorated. As a result, the brain pulls in resources from other areas. More specifically it taps in to the visual part of the brain.

You hear with your eyes

They proved that auditory areas of the brain were stimulated with a visual only stimulus in people with hearing loss. In simple terms it means people with hearing loss also hear with their eyes. They likely rely on visual context such as lip or behavioural patterns to hear.

They also showed that the frontal and pre-frontal areas of the brain become more active when sounds are made quieter which means people with hearing loss extend more effort in to listening.

The result of all of this is that when you have a hearing loss, more parts of your brain are active and you have to use more energy to listen. This makes you more tired and will likely struggle more in social situations.

What is most interesting about this study is that they have shown it happens even with mild hearing loss, such as in the client I saw.

Hidden Hearing Loss

Hidden hearing loss is something every audiologist has encountered. An individual attends the clinic saying they really struggle to hear, particularly in noisy situations. We do our audiogram and a basic speech test and we say, ‘your hearing is within normal limits’ knowing this doesn’t fit with their medical history or reported experience.

Recent research is now proving what we have always known to be true, that this is an incomplete and inaccurate summary of their hearing profile.

Liberman and Kujawa2 describe that in animal models, before hearing loss presents itself overtly, over exposure to noise can result in an interruption of communication between inner hair cells and cochlear nerve fibres. This is called cochlear synaptopathy. They predict that this disruption is a probable cause of speech in noise difficulties, tinnitus and hyperacusis.

The National Acoustic Laboratories have also performed a large study on cochlear synaptopathy3. Their results contribute to a growing body of evidence to show that in humans, it is a highly variable phenomenon. It is likely to be just one among several factors that affect an individual’s ability to hear speech in noise.

This leaves us in a bit of a grey area. The research is in its infancy stages but at present it is suspected that it is likely to be just one of many causes that may result in processing difficulties in noise. We can only make assumptions about the impact this may have on individuals until further research in this area is published.

Using the data

We now know that auditory deprivation and hidden hearing loss are real. So now I needed to spend time thinking about how I can change my clinical practice in real ways to adapt to this new evidence.

I could go to the extreme and say that I should be performing full medical history, high frequency audiometry, tympanometry, speech in noise, otoacoustic emissions, and measuring wave 1 on an ABR for every patient. However, like most independent audiologists, I do not have access to this specialist equipment nor is it practical or realistic.

When developing my change in local protocol I had this question at the forefront of my mind for every test, ‘Will this change the clinical outcome for the patient?’. If the answer is no, then I didn’t include it. So let’s go through the checklist:

Before the appointment

Family Centred Care

Encourage family members to attend the appointment if possible. Family centred care can help with the following:

  • Individuals more likely to seek help with hearing loss if family members are perceived to be supportive4
  • Adults with support from family members are more likely to be successful hearing aid users5

As well as this but the spouse of the individual with hearing loss is likely to have a third-party disability. This means that although the spouse does not have a health condition, they may experience activity limitations and participation restrictions as a result of the health condition of their significant other6.

During the Appointment

Medical history

Probably the most important part of the appointment. This gives you the opportunity to get to know the patient and their motivations and goals. It also highlights any risk factors that may affect any future clinical decision.

Protocol for medical history

  • Follow BSHAA guidance on Professional Practice for Hearing Aid Audiologists – this ultimately ensures I am practicing safely
  • Identify Specific Needs using the Client Oriented Scale of Improvement (COSI) – This helps me get to the root of their concerns and highlights where they wish to improve their quality of life. It is a simplistic form which is easily and quickly incorporated in to the clinical history.
  • Have an informal discussion about whether they attended off their own back or was it the family that encouraged the appointment. Their work and lifestyle can later influence the decisions I make when recommending appropriate intervention.

All of the above is critical for the appointment and every answer can influence the treatment I give later so it has to be included in every appointment. Marjolijn, my peer on LinkedIn, astutely said ‘the true degree or severity (of hearing loss) depends on personal perception in the first place; just like pain, (hearing loss) is subjective’.

Audiological Testing

Otoscopy

This is the bread and butter of audiology. It should always be performed at any appointment. The results of the examination can certainly change clinical decisions and so has to be included.

Audiometry

Follow BSA guidelines on performing audiometry and also ensuring that BSHAA guidance for hearing aid audiologists is followed. If they have been booked in for a short ear health check, then AC only is ok but if ANY hearing loss or other contraindication is apparent, then recommend they attend for a full diagnostic assessment or GP if appropriate.

As well as this, to account for hidden hearing loss, if they have identified difficulties hearing in noise from their medical history recommend they attend for a more thorough assessment. Use the following statement adapted from James Hall7 as an example:

“The results of a simple hearing test were within normal limits. However, given the concerns you mention, I would recommend you attend another appointment for us to conduct a comprehensive evaluation of your hearing, including tests that measure how your ears and your brain process sound.”

Tympanometry

Perform tympanometry if there is any indication of middle ear pathology from medical history or examination. However, as it only takes a couple of seconds to complete it can add to the overall picture for any patient.

Speech In Noise Testing

QuickSIN is my go to test. It is quickly administered within a clinical setting and is often built-in to verification equipment. This can help to make an appropriate recommendation for hearing aid technology. For people with speech in noise difficulties we know that hearing aids with directional microphones are more beneficial.

Explaining the Results

This is where it gets interesting and everyone will do it differently. I’ve been explaining hearing test results for over 10 years now and although the explanation varies from person to person it is easy to get stuck in a routine. I have always used the traditional classification system of mild, moderate, severe etc. This is what I was taught at university and I certainly know I’m not the only one still using it today.

However, with the discovery of hidden hearing loss I will be moving away from these classifications because they over-simplify a complex situation.  They can also undermine the medical history which may indicate a more severe difficulty in background noise.

Avoid negative words

The results of the assessment should not be described as a loss, or an impairment. These are negative words and will likely worsen the process of grief that the individual will inevitably go through. Instead I will now talk about how much they may gain from intervention. For a ‘mild’ hearing loss I will likely use a variation on the below:

“Today’s results are consistent with the concerns you described with your hearing at the beginning of the appointment (be more specific here and demonstrate active listening). It is great that you recognised these signs and took the initiative to seek advice. With early intervention using hearing technology we can look to improve your quality of life and reduce your listening effort.”

“Modern hearing technology can sit comfortably in or behind your ear without you really noticing it. However, what we hope will be noticeable is your improved ability to hear in the social situations you described.”

“We offer a trial period because the benefit from wearing a hearing aid varies from person to person. The ability to hear, particularly in noise, is a very individual experience. The only way to measure the benefit you may get is by trialling the technology. This is at no risk to you. You will be entitled to a full refund should you decide that the improvement in your hearing is not significant.”

When coming up with the above explanation I tried not to talk about loss, I feel I was still able to fully inform the individual of their results whilst affirming their original concerns. I think I was also able to realistically recommend the hearing technology without over or under promising on results.

I realise that it is impossible to create a blanket explanation for every individual but I wanted to construct the language I would use to reinforce new behaviours. Without writing it down in a generic form, I think I will find it difficult to articulate in the real world. What would your explanation be? Would it be similar? Please feel free to send in your comments or questions.

Summary

By changing nothing, nothing changes. Tony Robbins

From the result of a 15 minute appointment I have completely re-evaluated my approach to assessing and explaining hearing loss, particularly ‘mild’. It highlights that doing what we have always done for our clients isn’t always going to be the best for them. By adapting to new research we can keep on striving to deliver gold standard care to achieve the best outcome for our clients.

References

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