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Hearing loss is an issue that affects approximately 9 million adults in the UK. These figures are expected to grow to more than 14 million adults by 2035. Although only 2 million people in the UK currently use a hearing aid, it is thought that 6 million more people could benefit from one.
Today, we are going to look at hearing loss in more detail, including the common causes and treatments.
What is hearing loss?
Hearing loss is a common issue, which occurs particularly as people age. It most commonly occurs as a result of repeated exposure to loud noises. Hearing loss usually develops gradually, with someone’s hearing deteriorating over a period of time, usually months or years. However, it can also occur suddenly.
There are three major areas that make up the ear – the outer ear, the middle ear and the inner ear. All three areas are essential to hearing. Sounds waves pass through the outer ear, causing vibrations in the eardrum. The eardrum and three small bones of the middle ear amplify these vibrations whilst they travel to the inner ear. The vibrations then pass through the cochlea, which is a hollow, spiral-shaped bone in the inner ear. The cochlea transforms sound waves into electrical impulses that the brain interprets as individual sounds.
There are three main types of hearing loss:
- 1. Conductive: Hearing loss that occurs in the outer or middle ear.
- 2. Sensorineural: Hearing loss that occurs in the inner ear.
- 3. Mixed: Hearing loss that is both conductive and sensorineural.
Most types of hearing loss cannot be reversed; however, there are different treatments that can help to improve your hearing.
If you can hear between 0 to 20 decibel hearing level (dB HL) across the speech range, this is considered normal hearing. If you have a loss of 25 dB HL in one or both ears, this is considered a hearing loss. If your hearing loss is severe or impacts your ability to communicate and engage, it may require you to use a hearing aid.
Approximately 1 in 6 of the UK adult population is affected by hearing loss, equating to nearly 9 million people. The majority of these people, 88%, are above the age of 65.
What are the first signs of hearing loss?
Hearing loss rarely happens overnight. This can make it difficult for people to identify when they first began experiencing difficulties with their hearing. Being aware of the early signs of hearing loss allows for earlier diagnosis and more successful treatment.
Some of the first signs you may be experiencing hearing loss are:
Children’s voices become muffled or difficult to understand:
The cells in your inner ear that detect high-pitched noises are usually the first to fail. This means that even if you don’t have difficulties hearing other adults, particularly males or those with deeper voices, but you have difficulty hearing children, you may be beginning to experience hearing loss. You may also notice you no longer hear other high-pitched noises, such as the beeping of the washing machine or microwave or the sounds of birds in the early morning.
You have difficulty with conversations in noisy places:
You may find that you have no difficulties hearing during 1:1 conversations or conversations at home but in places such as restaurants, shops or pubs or places where there is more background noise, you find it more difficult to follow the conversation. You may pick up parts of the conversation or just miss two or three words in each sentence. However, this could be a sign of mild or early hearing loss.
Your TV volume is slowly increasing:
You may notice that you are slowly increasing the volume of your TV. Speech can be difficult for people with hearing loss to hear when there are background noises, noise effects and music playing at the same time. Increasing the usual volume on your TV, even by a couple of notches, could be a sign that your hearing is affected.
What level of hearing loss is considered a disability?
Hearing loss is usually categorised at different levels, from mild to profound:
Mild: 25 dB HL to 40 dB HL
Moderate: 41 dB HL to 55 dB HL
Moderate-Severe: 56 dB HL to 70 dB HL
Severe: 71 dB HL to 90 dB HL
Profound: Greater than 90 dB HL
There is not one specific level of hearing loss that classes as a disability. If your hearing loss affects the way you participate in day-to-day activities and prevents you from going to work or attending social situations, you may be able to receive an official classification as being disabled. In order to be defined as disabled and to qualify for disability benefits, your hearing loss will likely have to be severe or profound.
What is conductive hearing loss?
Conductive hearing loss is when there is a problem preventing sound from getting through the outer and/or middle ear. It can occur if a foreign object, liquid or a structural component of the ear blocks the outer or middle ear from transmitting sound waves to the inner ear. In many cases, conductive hearing loss can be treated and improved with medication or surgery, although this is not always possible, and the hearing loss may be permanent.
Some causes of conductive hearing loss are:
- A blockage in your ear canal (such as earwax).
- A hole in your eardrum.
- Fluid build-up in the middle ear (usually as a result of a cold or an allergy).
- A foreign object trapped in your ear.
- An ear infection.
- Abnormal growths or tumours.
- Structural defects in your outer ear or middle ear.
- Trauma to the outer ear.
- Narrowing of the ear canal.
- Otitis externa – swimmer’s ear.
- A blockage in the Eustachian tube, connecting the middle ear to the nose and throat.
Someone with conductive hearing loss may find it difficult to hear softer sounds and louder sounds may appear muffled. Conductive hearing loss usually involves difficulty with the volume rather than the clarity of the sounds. The hearing loss may be worse in one ear or only occur in one ear.
What is sensorineural hearing loss?
Sensorineural hearing loss occurs in the inner ear, the cochlea or the auditory nerve that delivers sound to the brain. This is the most common type of hearing loss and is always permanent. It usually occurs when there is damage to the stereocilia – the tiny hair-like cells of the inner ear or the auditory nerve that convert vibrations from sounds into electrical signals that travel to the brain. The damage can prevent or weaken the transfer of nerve cells to the brain.
There are many causes of sensorineural hearing loss, including:
- Exposure to loud noises.
- Head trauma.
- Ear abnormalities
- Auto-immune inner ear disease.
Sensorineural hearing loss can also be congenital, meaning it is present from birth. This could be as a result of a genetic syndrome or an infection that the baby contracted in the womb. Sounds are often muffled, making them difficult to hear, and distorted, making understanding difficult even if the volume of the sound is louder.
Although sensorineural hearing loss cannot be cured or treated, hearing can be improved using hearing aids or a cochlear implant.
What is mixed hearing loss?
Mixed hearing loss is a combination of sensorineural hearing loss and conductive hearing loss. It is a problem with your outer or middle ear and your inner ear. It usually involves damage to the outer or middle ear’s ability to transmit sound waves to the inner ear and the cochlea or the auditory nerve’s ability to process sound data and transfer it to the brain.
Mixed hearing loss can occur in one ear (unilateral mixed hearing loss) or both ears (bilateral mixed hearing loss). Mixed hearing loss may be caused by a combination of sensorineural and conductive hearing loss. The causes could be the same, such as a head trauma that affected multiple parts of the ear, or it could have different causes, such as sensorineural hearing loss from exposure to loud noises, combined with a hole in your eardrum.
Mixed hearing loss can result in more severe symptoms and can be more difficult to treat. Treatment will likely focus on what is having the most significant impact on your hearing, for example, if the majority of your hearing loss is caused by something conductive, treatment will focus on this rather than the sensorineural component. The conductive component is likely to be more easily treatable, with medication or surgery, than the sensorineural component, which can usually only be treated with sound amplification from a hearing aid or with a cochlear implant.
What is central hearing loss?
Central hearing loss is a result of a dysfunction of the central auditory pathway or the auditory cortex. Sound waves can travel through the ear, but the nerve pathway is not able to send electrical impulses to the brain, meaning that the hearing centres in your brain don’t receive sound signals correctly. This means that the ears and brain don’t coordinate properly.
It differs from other types of hearing loss because the person is able to detect sounds but may not be able to understand them. For example, you may misunderstand what someone is saying or be unable to understand and follow instructions or directions. The most well-known types of central hearing loss are auditory processing disorders, aphasia and auditory agnosia.
Central hearing loss doesn’t involve any problems with or damage to the ears. It is a permanent and usually irreversible condition, although there are treatments which can improve a person’s listening and concentration abilities.
What causes hearing loss?
Hearing loss has several different causes. Some of the most common causes of hearing loss are:
Exposure to loud noises:
Exposure to loud noises is one of the biggest causes of hearing loss. It could be long-term exposure, for example, at work or during recreational activities, that causes hearing loss, or a single loud sound, such as a gunshot, which causes hearing loss.
Noise levels are measured using a decibel (dB) scale. Sounds below 80dB are considered to be safe. Sounds above 85dB can result in hearing loss, particularly if you are repeatedly exposed to sounds above this level, for example, at work. However, the length of time that you are exposed to these sounds can also make a difference. You can be exposed to sounds of 85dB for up to 8 hours a day safely. For every 3dB above this, the safe time exposure halves. For example, you can be exposed to sounds of 88dB for 4 hours, 91dB for 2 hours, 94dB for 1 hour and 97dB for only 30 minutes.
Loud noises damage the hair-like cells in the cochlea that convert vibrations from the sound waves into neural signals that are carried to the brain. Hearing loss usually occurs when 30%–50% of these hair-like cells are damaged.
Some examples of the decibel scale are:
|Decibel (dB) Level||Safe Time Exposure||Example sounds|
|30dB||No limit||A whisper|
|60dB||No limit||A conversation spoken at normal volume|
|70dB||No limit||A washing machine or dishwasher|
|85dB||8 hours||Heavy traffic or a food blender|
|91dB||2 hours||A pneumatic drill|
|94dB||1 hour||A motorcycle|
|97dB||30 minutes||An industrial fire alarm|
|100dB||15 minutes||A nightclub|
|110dB||Less than 2 minutes||A loud music concert or a chainsaw|
|120dB||Less than 7 seconds||An ambulance siren, the sounds of thunder|
|130dB||Not safe||The sound of an aeroplane taking off from close proximity|
|140dB||Not safe||The sounds of a firearm or fireworks|
140dB is the noise level which causes pain for most people, although some people experience pain at lower decibels.
Earwax can cause conductive hearing loss. This is because impacted earwax can block the ear canal and sound waves cannot properly travel through the ear canal, which can result in hearing loss. Although earwax can cause temporary hearing loss and can be alleviated if the impacted wax is safely removed, not removing the wax safely or leaving it for too long (approximately 12 months or longer) can result in permanent hearing loss.
Presbycusis, also known as age-related hearing loss, can occur for many reasons, such as changes in the inner ear and the auditory nerve, wear and tear to the hair cells in the inner ear, repeated exposure to loud noise and a decline in the function of your inner ear. Age-related hearing loss usually affects both ears equally and occurs gradually.
Ear infections that occur multiple times or lead to a build-up of fluid in the eardrum or middle ear can cause permanent hearing loss. Ear infections only usually result in temporary hearing loss; however, permanent hearing loss can occur if the ear infection causes damage to the eardrum, the bones of the ear or the nerves.
A perforated eardrum, which is a hole or tear in the tissue separating the ear canal and the middle ear, can cause temporary or permanent hearing loss. If the perforation is larger or the small bones inside the ear are also damaged, the hearing loss is more likely to be permanent. Perforations can occur as a result of ear infections, injury to the ear, a sudden loud noise, a sudden change in air pressure and foreign objects in the ear.
Abnormal bone growths or tumours:
Cysts and tumours in the ear or otosclerosis, which is abnormal bone growth inside the ear, can cause hearing loss. They can cause the bones in the inner ear to become blocked or fuse together and can mean that sound no longer travels properly. In some cases, the hearing loss can be treated, usually with surgery, but in other people, the hearing loss is permanent.
The cochlea is extremely sensitive to reduced blood supply and this can result in irreversible damage to the cochlea and permanent hearing loss. High blood pressure, hardening of the arteries, thrombosis, strokes and heart attacks can all result in hearing loss.
Diabetes can also cause sensorineural hearing loss. High blood sugar levels can cause damage to the blood vessels and nerves in your inner ear. This can cause disruptions in how nerve signals and sounds travel from the inner ear to your brain and result in permanent hearing loss.
Another cause of sensorineural hearing loss is a group of medications called ototoxic medications. They are only usually used to treat life-threatening conditions, such as cancer or severe infections. Ototoxic medications can also cause tinnitus.
What are the signs and symptoms of hearing loss?
It can be difficult to tell if you have hearing loss, particularly if your hearing loss has occurred gradually.
Some signs and symptoms of hearing loss can include:
- Difficulty hearing other people clearly, particularly in noisy places.
- Misunderstanding people frequently.
- Feeling like speech and other sounds are muffled.
- Difficulty hearing consonants (particularly s, h and f).
- Difficulty hearing higher pitched noises, such as birds chirping, some musical instruments, high-pitched voices or the sound of the doorbell.
- Frequently needing people to repeat themselves or speak more slowly or clearly.
- Difficulty hearing on the phone.
- Needing to listen to music or watch television at a higher volume.
- Finding it difficult to keep up with conversations.
- Feeling stressed or tired from needing to concentrate while listening or finding yourself disengaging or withdrawing from conversations.
- Avoiding certain situations because of your difficulty hearing.
- Relying on lip reading.
However, it can be more difficult to recognise the signs of hearing loss in babies and young children. Your child will likely have had their hearing checked during the newborn screening and the results may have shown no abnormalities. However, this does not mean that your child does not have hearing loss or difficulties hearing.
Some signs of hearing loss in babies and young children are:
- Not being startled by loud noises.
- Not turning towards a sound (usually after 6 months of age).
- Not speaking or repeating words or noises (usually by 12 months of age).
- Not reacting to their name.
- Seeming to hear some sounds but not others.
- Not recognising familiar voices.
- Delayed language development.
- Needing you to repeat questions or instructions multiple times.
- Looking in the wrong direction in response to a sound.
How to prevent hearing loss
There are several risk factors that can cause damage to your hearing or lead to hearing loss. Being aware of these risk factors can enable you to prevent hearing loss.
Some of the risk factors for hearing loss are:
- Older age: Your inner ear structures can degenerate over time, resulting in hearing loss.
- Exposure to loud noises: Loud noises can cause damage to the cells and membranes in your inner ear. The hair cells in your cochlea can become overworked from repeated long-term exposure and these cells can die.
- Genetics: Hearing loss can be genetic, with some people more susceptible to inner ear degeneration or ear damage than others.
- Occupational noise: Working in a workplace or job with consistent exposure to loud noises can result in hearing loss. Examples include farming, construction work, factory work, carpentry and the music industry.
- Recreational noise: Recreational activities can result in hearing loss, particularly if you partake in them regularly or over a number of years. For example, regularly attending loud concerts, using firearms, and using jet skis, motorboats or motorbikes can all cause hearing loss.
- Medication: Certain types of medication can cause damage to the inner ear. The damage may be temporary or permanent and may include tinnitus or hearing loss. Types of medication can include some chemotherapy medications, certain types of antibiotics and high doses of antimalarial medication.
- Smoking: Smoking tobacco makes you 70% more likely to develop hearing loss. Even being exposed to second-hand smoke can increase your likelihood of developing hearing loss, with non-smokers who live with a smoker twice as likely to get hearing loss.
Although some types of hearing loss cannot be prevented, many of the causes of hearing loss are avoidable and preventable.
There are some steps you can take to prevent hearing loss, including:
Check the noise levels in your workplace:
If you are unsure whether the noise in your workplace exceeds 85dB, you should ask your manager or the business owner to check the noise levels. This can be done using a walk-through survey, a sound level meter (SLM), an integrating sound level meter (ISLM) or a noise dosimeter. If you need to raise your voice to speak to someone standing close to you (within two metres), the noise in your workplace is likely at a hazardous level.
Your employer must comply with the Control of Noise at Work Regulations (2005), including carrying out a risk assessment, using quieter equipment, planning for noise breaks and ensuring employees use personal hearing protection.
Reduce your exposure to loud noise:
Long-term exposure to loud noises (above 85dB) and short-term exposure to loud noises (above 90dB) can cause permanent and irreversible damage to your hearing. If you are exposed to loud noises at work, during recreational activities or at any other time, there are some steps you can take to reduce the likelihood of any damage occurring.
- Wear personal hearing protection, such as noise-reducing headphones or earplugs.
- Keep the volume of music at a safe level.
- Reduce your time in noisy areas and take regular noise breaks.
- Move away from the noise, where possible.
- Consider the noise ratings of your household appliances.
- Assess the noise in cinemas, gym classes and theatres to ensure it is not too loud.
Reduce or prevent exposure to damaging chemicals:
Some chemicals, such as carbon monoxide, cyanides, pesticides and styrene, can cause permanent noise-induced hearing loss. Chemicals from fumes, mists, gases and vapours can cause damage to the nerve fibres and hair cells in your inner ear. This can cause hearing loss and tinnitus. These chemicals can be inhaled, ingested or absorbed through the skin. You can prevent exposure to these chemicals by using less toxic chemicals, wearing personal protective equipment (PPE) at all times and following all chemical safety instructions and procedures. Stopping smoking can also reduce your exposure to the damaging chemicals in tobacco.
Be careful when removing earwax:
Many people use cotton buds to remove earwax from their ears. Although earwax can be unsightly and can make you feel like your hearing is muffled, using cotton buds to remove it can instead push the wax deeper into your ears. This can cause an ear canal blockage which can result in conductive hearing loss. Cotton buds can also cause damage to your eardrum. Instead, you should use earwax removal drops or an earwax irrigation kit to soften and flush out the earwax.
What are the complications of hearing loss?
Hearing loss can have a significant negative impact on many aspects of a person’s life.
Hearing loss can result in difficulties hearing and understanding other people. This can make conversation difficult and can lead to embarrassment, withdrawal from conversations, avoidance of social situations and isolation. Research studies also show a link between hearing loss and depression, with between 11% and 20% of adults with hearing loss also having depression.
Depression could occur as a result of the social isolation many people with hearing loss experience and the loss of enjoyment they may feel from being unable to hear sounds they enjoy or being unable to do things they previously loved, such as listening to or playing music.
People who experience hearing loss also commonly experience tinnitus, a ringing, roaring, clicking, hissing or buzzing in their ears. Tinnitus can cause sleep disruptions, difficulty concentrating, memory problems, stress and frustration.
Both hearing loss and tinnitus can impact your ability to function at work, at home and socially. There are also some safety concerns associated with hearing loss, such as being unable to hear a smoke alarm or fire alarm, a call of distress or not hearing someone breaking into your home.
Research has also found links between hearing loss and increased heart rate and blood pressure, both of which can be factors in heart attacks and strokes. There is also a possible link between untreated hearing loss and dementia.
How is hearing loss diagnosed?
If you think you may be experiencing hearing loss, you should see your GP as soon as possible or visit your local pharmacy or optician for a free hearing test. However, if your hearing loss occurs suddenly, or you experience other symptoms such as ear discharge or vertigo, you should seek medical help quickly, by requesting an urgent appointment with your GP or contacting 111.
Whether you are experiencing gradual or sudden hearing loss, your GP will carry out some simple hearing tests. They will also conduct a physical examination of your ear using an auriscope (an instrument with a light attached). This allows them to look for anything unusual or abnormal that could explain your hearing loss, such as an infection, a blockage or a perforated eardrum.
Your GP will also ask questions such as when you first noticed your hearing loss, how often it happens (including the types of noises and sounds you struggle to hear) and any other symptoms you experience. Your GP will likely then refer you to an ENT (ear, nose and throat) specialist or an audiologist (a hearing specialist).
The specialist will carry out further, more in-depth hearing tests. These can help to determine what type of hearing loss you are experiencing, the cause of your hearing loss and how severe it is.
Some of the hearing tests the specialist may perform include:
- A tuning fork test: This can help determine whether your hearing loss is conductive or sensorineural. A tuning fork is a metallic object that produces sound waves at a fixed pitch. The fork is gently tapped and moved to different places around your head, and you must indicate when you are no longer able to hear the sound.
- A pure tone audiometry test: This tests the hearing in both of your ears. An audiometer produces sounds at different volumes and frequencies. Wearing a pair of headphones, you must push a button every time you hear a sound. It can measure the sensitivity of your hearing to determine what volume and frequency of sound you are able to hear.
- A bone conduction test: This test identifies sensorineural hearing loss by testing the functionality of your inner ear. A vibrating probe is placed against the mastoid bone in your inner ear. Sound is then transmitted through the bone to test how well you can hear it.
- A word recognition test: This is used to evaluate your ability to discriminate differences between the speech sounds in various words. It determines how clearly you can hear words. The test involves you listening to and repeating words.
- Otoacoustic emissions (OAEs): This type of test is used to assess how well your cochlea is functioning. It measures otoacoustic emissions that are given off by the hair-like cells in the inner ear when responding to sound. The test measures the amount of OAEs you produce. Someone with hearing loss will produce fewer OAEs. The test involves a small earphone or probe being placed in your ear.
Although there are other hearing tests available, these are the most frequently used tests. The type of test you will undergo will likely depend on the type of hearing loss that is suspected.
What is the treatment for hearing loss?
Treatment for hearing loss can vary, depending on what is causing it and how severe the hearing loss is. Some types of conductive hearing loss can be treated by your GP, for example:
- An ear infection can be treated with antibiotics.
- A build-up of earwax can be treated with ear drops or removal of the build-up.
- Corticosteroids can reduce the swelling of cochlear cells.
However, some types of hearing loss, particularly sensorineural hearing loss, can be more difficult to treat. Many types of hearing loss are degenerative, meaning they get worse over time. Early treatment and an effective treatment plan can therefore slow down your hearing loss.
Your doctor or specialist will create a treatment plan based on the cause of your hearing loss and the severity.
Your treatment options include:
- Surgery: Hearing loss that is caused by abnormalities in the bones of your ear or your eardrum or by a growth or tumour, can often be treated with surgery. Surgery can help to correct any abnormalities or remove any growths or blockages. Surgery may also be recommended if your hearing loss is due to a repeated build-up of fluid that doesn’t drain.
- Hearing aids: A hearing aid can be beneficial if your hearing loss occurs as a result of damage to your inner ear, for example, from repeated exposure to loud noises. A hearing aid can make sounds louder or clearer and direct the amplified sound into your ear canal. There are different types of hearing aids, with the most common ones being in-the-ear (ITE) hearing aids and behind-the-ear (BTE) hearing aids.
- Cochlear implants: Cochlear implants may be recommended if you have severe to profound hearing loss. A cochlear implant avoids any damaged parts of your inner ear and, instead, directly stimulates the cochlear nerve. A cochlear implant is a small electronic device that is surgically placed under your skin and also has an external part that sits behind your ear.
- Hearing rehabilitation: This is a type of therapy that helps you to adjust to hearing loss and the use of hearing aids. It can help you to use aids effectively and learn visual cues and lip reading to improve your communication.