What does it mean to have a mild hearing loss?
Many patients who are seen for an audiological assessment may be diagnosed with a mild hearing loss, and they often wonder if hearing aids are necessary (or even helpful) for this. To answer this question, it is first important to better understand what a “mild” hearing loss means. In a future article, I plan to discuss the audiogram (the graph that displays the results of a hearing test) more in depth and how to interpret this, but for the purposes of this article, I will focus specifically on what a mild hearing loss is. Contrary to popular belief, we do not calculate hearing loss as a “percentage”; in other words, we do not diagnose someone as, for example, having a 30% hearing loss, or 60% hearing loss. Rather, we talk about hearing loss in terms of “degree of severity”. This means that a hearing loss will be referred to as either mild, moderate, severe, or profound.
To make things a bit more complicated, a patient may have a hearing loss that ranges in severity. For example, someone may have a hearing loss that is categorised as a “mild to severe hearing loss”. This is because the degree of hearing loss depends on the frequency of sound that was assessed. If you’ve had a hearing test before, you probably noticed that you heard beeps of varying pitches. Some of the beeps were low pitched, others were higher pitched. A person may have only a mild degree of hearing loss for low pitched sounds, but a severe degree of hearing loss in the high pitches. Indeed, most often, patients will have a hearing loss that ranges in severity to some extent or another. This is due to how the inner ear organ primarily responsible for hearing—the cochlea—is arranged and processes sound—and consequently where damage to this organ will affect certain frequencies of sound more easily than others.
Now, suppose someone is diagnosed with a mild hearing loss. Not a mild to severe hearing loss, not even mild to moderate—but just “mild”. The cut off between “normal” hearing ability and hearing loss is at around 25 decibels. A mild hearing loss begins if sound is required to be at least 25-30 decibels for you to just barely hear it. If you can hear sounds softer than this, then that would be considered “normal”. Alternatively, if sounds need to be even louder than this; for example, more than 40 decibels, then the degree of hearing loss would begin to cross over from “mild” into “moderate”. If someone is diagnosed with a mild hearing loss, then we still need to know one more piece of information—what frequencies (essentially “pitches”) are affected? For example, someone may have a mild hearing loss that just affects the highest frequencies that are routinely assessed, and can hear all other frequencies within normal limits. Someone else may have a mild hearing loss that affects all the frequencies tested; ranging from the lowest pitches to the highest pitches.
How does a mild hearing loss affect people?
Low frequencies tend to affect your perception of loudness, while high frequencies tend to affect your perception of clarity. Someone with a mild hearing loss affecting both low and high frequencies will probably feel more impacted by the hearing loss on a day-to-day basis, than someone with a mild hearing loss only affecting the high frequencies. Someone with the latter type of hearing loss may only notice difficulties occasionally, perhaps misunderstanding people at times, especially if there is lots of background noise or multiple conversations. On the other hand, someone with the former type of hearing loss may feel that they strain to hear conversations daily, and this becomes increasingly difficult the more complex and busy the environment becomes. However, it is important to note that the experience of hearing loss can be highly subjective and variable and can be based on many different factors beyond just the results of a hearing test. There are people with mild hearing losses that may be completely unaware of any hearing or communication difficulties at all; while others with a similar hearing loss may feel that they really struggle to hear and communicate, and that it is affecting their quality of life and relationships.
So how about hearing aids for a mild hearing loss?
Hearing aids can work very well for people with a mild hearing loss and are routinely recommended for patients with this degree of hearing loss. Hearing losses that arise from the inner ear (the type of hearing loss most typically associated with ageing and noise exposure) generally decline further with age. Hearing aids take some time to get used to, in terms of how they physically feel, but more importantly, in terms of how they sound. If your hearing loss is mild, that process will be much easier than waiting until your hearing worsens. Hearing really happens in the brain, rather than the ears. The brain essentially must relearn and retrain itself on hearing properly again—the greater the degree of hearing loss, the more the brain will have to learn and adapt to once it is receiving stimulation via sound again.
Will I become reliant on hearing aids earlier than I need to?
A common question that I often hear in the clinic, is “won’t hearing aids make my hearing worse”? The expressed concern, particularly with a mild hearing loss, is that by wearing hearing aids, one will become reliant on needing them to hear better, and thus making the person’s hearing ability less sharp than it would be, had they not begun to wear hearing aids in the first place. It is really the exact opposite! Research has suggested that hearing aids can help slow down the negative effects that hearing loss has on your ability to comprehend speech and interpret sound. Again, hearing really happens in the brain, rather than the ear. The hearing nerve sends sound to the auditory cortex in the brain for processing. If the brain is not receiving adequate stimulation, it can weaken and gradually lose the ability to make sense of the sounds it does eventually hear. This concept is referred to as “auditory deprivation”, where the auditory system gets deprived of sound stimulation for an extended period. That means that if someone has a hearing loss that remains untreated for a long time, that individual may struggle to make sense of the sounds and speech they do hear once they finally begin to wear hearing aids. This can often lead to frustration and a sense that the hearing aids aren’t really helping. However, if the same individual began wearing hearing aids earlier on, perhaps when their hearing loss was milder, they may well have had a better treatment outcome with their hearing aids.
What about all these articles that I see linking untreated hearing loss with dementia?
Audiologists frequently point to research that suggests a link between untreated hearing loss and an increased risk of cognitive decline and dementia, and there is certainly truth to this. This is related to the problem of auditory deprivation discussed above. The theory is that when individuals have difficulty hearing and understanding speech due to untreated hearing loss, it can lead to reduced cognitive stimulation and increased cognitive load. In other words, the brain isn’t getting enough information and stimulation from its environment and is having to direct more of its resources to understand speech and other sounds. This can lead to increased mental fatigue and reduced cognitive capacity for other tasks. This may, over time, contribute to changes in brain structure and function that are associated with cognitive decline and an increased risk of developing dementia. Furthermore, untreated hearing loss can lead to social and emotional isolation, which has also been shown to be associated with dementia.
However, in scientific research, we make an important distinction between “correlation” and “causation”. So, just because untreated hearing loss has been found to be associated (i.e. correlated) with dementia, does not necessarily mean that it causes dementia. A landmark study recently released in a July 2023 issue of the medical journal The Lancet sought to investigate, via a randomised trial, if the use of hearing aids could indeed reduce cognitive decline in older adults with hearing loss. The study found that for people who were already at risk of cognitive decline, a 48% reduction in this decline was seen over a three year period after being fitted with hearing aids. These are some very encouraging results regarding the potential benefits of hearing aids in reducing cognitive decline. The relationship between the two, is still being studied though, and more research would be required to make any definitive conclusions about this association. An excellent article released from the Hearing Journal looks at this relationship in more detail, and explores some of its misconceptions.
Isn’t a mild hearing loss just normal for my age?
Hearing loss that is associated with ageing is referred to as presbycusis, and this is what we would classify as a sensorineural hearing loss, which most typically arises from problems with the functioning of the cochlea in the inner ear. The degree of hearing loss seen for different age groups can range quite dramatically. Suppose you are 65 years old and have recently been diagnosed with a mild hearing loss. Indeed, many other people who are around your age may have a similar degree of hearing loss. And many others may have hearing that is completely within normal limits. And yet others will have a much more severe hearing loss—still predominantly due to ageing.
It would therefore be difficult to provide an “average” level of hearing loss that provides a good, genuine reflection of what degree of hearing loss can be expected at a certain age. It also isn’t particularly helpful to think of a hearing loss as being “normal” for one’s age. This is because lots of conditions are associated with ageing, yet that doesn’t mean they should be ignored. For example, you may also have been diagnosed with high blood pressure and have started taking medication for this. You may also notice that many other people in your age group are doing the same. That’s because it is an important health condition that needs to be addressed, whether it’s common for your age or not. I would encourage my patients to think of hearing loss in a similar light.
Are there situations where hearing aids wouldn’t be recommended for a mild hearing loss?
A recommendation for hearing aids isn’t based on the hearing test result alone. I would want to know if your hearing loss has been affecting you, and in what way. Have you noticed difficulties with your communication? If not, what about your family and friends? Have they commented to you that you haven’t been hearing them well—maybe they were the ones to encourage you to get it checked in the first place? If you really aren’t having any concerns with your hearing yourself, then you may not feel motivated to wear hearing aids. To be successful with hearing aids, they do require consistent, daily use. If you don’t feel that you have a hearing problem, then you understandably won’t want to wear your hearing aids. When you do wear them, you then may feel that they just make everything uncomfortably loud and harsh sounding, without benefitting you—which would only make you want to wear them even less frequently. It is important to feel “ready” for hearing aids—that it is something you feel you need and want. If you don’t quite feel like this, then I’d probably advise you to come back and get your hearing reassessed in another year or two, so that we can revisit your situation and monitor your hearing loss.
Some final thoughts
If a patient with a mild hearing loss attends my clinic, I would certainly recommend hearing aids for them. Even though the hearing loss may be mild, it can still have a noticeable impact on one's ability to understand speech and participate fully in conversations. A hearing aid will help overcome this. Furthermore, it is much easier for the brain to adapt to hearing aids while the hearing loss is still mild, and this can potentially have significant benefits for one’s overall cognitive health, not to mention their social and emotional wellbeing too. However, if you don’t feel quite ready to start wearing hearing aids, there is nothing wrong with waiting a year or so, to give yourself some time to consider how your hearing loss may be impacting you, and to ensure that you will feel motivated to wear hearing aids. They are, after all, your ears, and not anyone else’s!
If you'd like to learn more about the kind of hearing care we provide for our patients at Finchley Hearing, please explore our website and feel free to get in touch with any questions. We're a private, independent audiology practice in London committed to ethical, evidence-based practices and would love to help you on your journey to better hearing.
If you found this article helpful, please consider sharing it via one of the social media icons on the bottom of this post. You can also subscribe to our blog through the form at the bottom of this page, to stay updated whenever we post a new article.