Think back to the last time you had to ask someone to repeat themselves. Maybe there was a great deal of background noise. Maybe they were speaking too softly.
Or maybe you are suffering from mild to moderate hearing loss.
Many people struggle with the same questions once they begin to notice a decline in their hearing. “Am I losing my hearing? What level of hearing loss requires a hearing aid? How effective are hearing aids? Do I need a hearing aid for mild hearing loss? Can mild hearing loss be corrected?”
The answers may surprise you! Hearing loss isn’t limited to extreme cases. A recent study found that over 700,000 New Zealanders are affected by hearing loss.
If you feel you might be one of those people, read on to find out if a hearing aid can help you.
Causes of Hearing Loss
Despite what you might think, old age is not the only reason a person experiences hearing loss. Sensorineural, conductive, and mixed hearing loss have a variety of causes.
Sensorineural hearing loss (SNHL) represents about 9 in 10 cases of reported hearing loss. Age-related hearing loss (presbycusis) is the most common form of SNHL and noise-induced hearing loss is the second.
The second most common type of hearing loss is called conductive. This is when something is physically blocking or damaging the ear and keeping sound from reaching the inner ear.
Ever had a bad ear infection and had to suffer through muffled, underwater sounds till it got better? That’s a good example of conductive hearing loss. A few others include water blocking your ear, Eustachian tube dysfunction, or just too much wax in there.
Conductive hearing loss isn’t usually permanent. It often gets better once you address the underlying problem. It’s often hard to figure out what that problem is without a consultation with a general practitioner or an audiologist.
Finally, you may be suffering from mixed hearing loss. This is when sensorineural and conductive hearing loss happens at the same time. Again, getting your hearing tested will be the first step in figuring out what’s causing the problem.
How Hearing Loss is Measured
When you have a hearing test your hearing ability is measured in “levels” from mild to profound. Each level is categorised by a range – or level – of decibels concerning the frequencies of human hearing and speech.
Measuring Decibels and Perceived Volume
Decibels represent sound intensity or amplitude. The higher the number of decibels, the louder a sound is. Decibels are measured on a logarithmic scale which is different to a linear scale.
A linear scale is more relatable for most people as we often encounter it in our daily lives. An example of a linear scale is a ruler measuring distance. The markings on a ruler are of equal distance to one another making them linear.
A logarithmic scale is not linear and represents exponents (or powers) of a base number. You might remember exponents from maths class in school. An example is 5 to the power of 2, where 5 is the number and 2 is the exponent explaining how many times to use the number in a multiplication. In which case it is 5 x 5 = 25.
In the case of decibels (dB), for every 10-dB rise, there is a 10-fold increase in sound intensity and we perceive this as being 2-times louder in volume.
The below table shows the logarithmic scale in more detail.
|Decibels||Perceived Volume Increase||Increase in Sound Intensity (Engergy)|
The table is also plotted on a bubble graph for those of us that prefer a visual reference to the data, however, the scale involved in sound intensity is huge so it requires some imagination to comprehend.
A normal face-to-face conversation is about 60 dB. The siren from an ambulance is about 120dB and it’s unsafe to listen to up close for longer than 9 seconds. If you’re ever strapped to the roof of an ambulance wear hearing protection.
The increase in sound intensity or the extra energy it takes to produce the sound from 60 dB and 120 dB is 1-million times! And you would perceive the volume increase as being 64 times louder.
All of this might sound a little complicated, but don’t worry it sometimes confuses the best of us! The important things to remember are:
- The scale is not linear, but logarithmic. For example, the difference between the perceived volume and sound intensity between 40 dB and 50 dB is not the same as it is between 50 dB and 60dB.
- Sound intensity is the energy required to create a given level of sound. And the perceived volume increase is the level at which a person hears or interprets the difference in the volume of the resulting sound.
Levels of Hearing Loss
The lowest level of hearing loss is called “mild“. This means that people have difficulty hearing speech below 26 to 40 dB. This can be particularly noticeable when someone is talking while not facing you, or if you are talking to a child who speaks softly (and in the higher frequencies). One might think that mild means it has little to no effect on a person’s daily life, but listening fatigue, falling behind at school or work, and feelings of isolation aren’t mild at all.
In childhood, it’s easier to notice when someone can’t hear the teacher in class. As a person enters adulthood hearing loss is often just brushed off as something that happens to us as we get older. There’s growing evidence to suggest doing something sooner rather than later is a good idea.
One level up is “moderate” hearing loss. A person with hearing loss in this range has trouble hearing speech softer than 41 to 55 dB. You might realise you can’t hear the phone ringing or have trouble understanding someone when they’re talking at a normal volume in the presence of background noise.
“Moderately severe” hearing loss is the next level and this is where hearing normal conversation is a real struggle. Any conversation under 56 to 70 dB is not loud enough to be heard.
Remember a normal face-to-face conversation takes place at about 60 dB.
“Severe” hearing loss level is where conversational speech cannot be heard and the threshold is 71 to 90 dB.
“Profound” hearing loss caps off the spectrum, meaning the inability to hear speech under 91 or more decibels.
When you have a full diagnostic hearing test your hearing ability is charted on an audiogram and this provides you with your level of hearing loss.
What is an Audiogram?
An audiogram is the result of a pure-tone hearing test to measure hearing sensitivity. The audiogram plots sound you can hear at different frequencies (pitch) and decibels (volume).
Frequency is a measure in hertz (Hz). Humans with normal hearing can hear sounds between 20 Hz and 20,000 Hz.
An audiogram will describe hearing sensitivity from normal to profound loss.
The stylised audiogram below plots normal hearing and all levels of a sloping hearing loss in relation to:
- a speech banana
- face to face conversational speech between two adults
- the frequency of various letters when spoken
- the volume and frequency of various sounds like a bird singing and a band playing.
A speech banana is not a delicious snack for audiologists, but the audible region of phonemes or various sounds of human speech plotted on an audiogram. You can see how isolated sounds from speech cover a wide range of frequencies and volumes.
Try this out for yourself! Phonetically sound out some parts of speech:
- eɪ – which is in words like, say or eight
- tʃ – such as in, check or church
- ɔɪ – for example, boy or join.
Notice the difference in both volume (how loud it sounds) and frequency (how deep or high pitched it sounds).
For people with normal hearing, they can hear all the frequencies at all the volumes on an audiogram.
For someone with mild hearing loss, they fail to hear the sounds above the pink line such as birds chirping and leaves blowing in the wind.
Depending on the severity of mild hearing loss they may also fail to hear sound from above the green line, which includes some speech sounds in the speech banana. Even with a mild loss, there is potentially a reduction in speech comprehension. This loss of ability to hear speech might be unnoticeable as people often alter their behaviour to compensate.
With a moderate hearing loss, the level begins at the green line and depending on the severity it can reach to the blue line. This is where face to face conversational speech at a normal volume starts to become difficult to hear.
Can you start to see the pattern forming? For example, the lower threshold for the mild hearing loss level is the pink line and the upper limit is the green line.
Prevalence of Hearing Loss in Young People
You could be forgiven for thinking that hearing loss is an old person’s disease. After all, the natural process of aging is a cause of hearing loss common to us all – called presbycusis. However, this isn’t simply isn’t the case. Young people are arguably increasingly susceptible to hearing loss in a world where it’s estimated noise pollution doubles or triples every 30 years and the use of smartphones, earbuds and headphones are no doubt taking a toll.
A study done on the social and economic costs of hearing loss in New Zealand found that a large number of younger people were being affected. 21,480 out of 600,144 people with mild hearing loss were between the ages of 0 and 20.
This prevalence isn’t isolated to one country; the World Health Organization (WHO) reports that 34 million children worldwide suffer from hearing impairment.
Babies and young children are most at risk from complications at birth, genetic causes, certain diseases, recurring or chronic ear infections, medical treatment with particular drugs, and exposure to excessive noise.
The WHO also reports 1.1 billion young people aged between 12–35 years are at risk of hearing loss from exposure to noise in recreational settings. For example, excessive use of headphones and earbuds, going to loud concerts and bars or playing music in a band are all scenarios where damage to your hearing is a distinct possibility.
The point is, your age is not the deciding factor on whether or not you have a hearing loss. To be certain, go and get a hearing test. You can start with an online test and then graduate to an in-person hearing screening, both of these are free (at least at Ear Health they are) and only take a few minutes of your time.
Depending on the hearing screening results you might require a full diagnostic hearing test which takes about an hour to complete and costs about $90. At the end of the full diagnostic test, you will receive documentation about your hearing ability including an audiogram.
Upgrading From ITD Hearing Aids
A common form of listening device is the ITD, or “in-the-drawer” style. This model features outdated technology that causes the user to experience annoying feedback whistles, improper fitting, and a hearing experience that isn’t best tailored to their specific needs. As a result, the user throws them in a drawer and ends up resigned to the idea that hearing aids just don’t work for them.
This leads to some people believing they must settle for a lower quality of life. So how can this problem be addressed?
Back in 1999, MarkeTrak V surveyed hearing aid users. They asked people to write a letter detailing whether they wore their hearing aids and, if they didn’t, explain what they saw as the problem. More than 16% of users said they had decided not to use their hearing aids at all, citing not only whistling feedback but improper fit and high cost as the reasons.
Compare that to a 2019 MarkeTrak10 survey that found 79% of hearing aid users wore them daily, along with other significant improvements in satisfaction rates. These improvements include digital microchip technology that allows sounds to be amplified according to a user’s unique hearing prescription.
Other advancements in the last 20 years include Bluetooth capability, smartphone apps, remote controls, rechargeable batteries, feedback (whistling) elimination and wind noise reduction.
In terms of technology, hearing aids have advanced significantly and it can be argued they are much less likely to end up in your sock drawer.
Aesthetically they are also more appealing with components getting smaller and even high-powered hearing aids are now small and discreet.
Do You Need a Hearing Aid for Mild Hearing Loss?
The truth is that even people with mild hearing loss are candidates for a hearing aid. The same study that found statistics on how many young people are affected also showed that those with mild hearing loss were in the overwhelming majority. Over 600,000 out of 880,350 overall cases in New Zealand alone reported mild hearing loss.
Treating the problem with a hearing aid while it’s still in the mild range will help you to maintain your quality of life and stay engaged in social situations. This has a myriad of potential health benefits including:
- Improved relationships through maintaining or improving intimacy, communication and independence.
- Enhanced career prospects by being able to sustain communication ability in a broad range of workplace scenarios.
- Keeping the mind stimulated and possibly decreasing the risk of cognitive decline, brain shrinkage and dementia.
- Minimising the risk of depression and other mental illness that may result from the isolation, loneliness and stress experienced with untreated hearing loss.
So if you’ve been finding yourself wondering why people won’t stop muttering or have been noticing that some words aren’t coming through clear, don’t hesitate to discuss with one of our audiologists. We can help you address the issue now before it becomes an even bigger problem.