What is hearing loss?
Hearing loss is a common problem that often develops with age or is caused by repeated exposure to loud noises.
Hearing loss can occur suddenly, but usually develops gradually. General signs of hearing loss can include:
- difficulty hearing other people clearly and misunderstanding what they say
- asking people to repeat themselves
- listening to music or watching television with the volume turned up high
Read more about the symptoms of hearing loss.
When to see your doctor
See your doctor if you're having problems with your hearing, or your child is showing signs of hearing difficulty, particularly if you lose the hearing in one ear. If you lose your hearing suddenly, you must see your doctor as soon as possible. They can check for any problems and may refer you to an audiologist (hearing specialist) or an ENT surgeon for further tests.
Read more about diagnosing hearing loss.
Why it happens
Hearing loss is the result of sound signals not reaching the brain. There are 2 main types of hearing loss, depending on where the problem lies:
- sensorineural hearing loss – caused by damage to the sensitive hair cells inside part of the inner ear called the cochlea or the auditory nerve; this occurs naturally with age or as a result of injury
- conductive hearing loss – when sounds are unable to pass from your outer ear to your inner ear, often as the result of a blockage such as earwax, glue ear or a build-up of fluid due to an ear infection, a perforated ear drum or a disorder of the hearing bones
It's also possible to have both these types of hearing loss. This is known as mixed hearing loss. Some people are born with hearing loss, but most cases develop as you get older.
Read more about causes of hearing loss.
Preventing hearing loss
It isn't always possible to prevent hearing loss if you have an underlying condition that can cause you to lose your hearing. But there are several things you can do to reduce the risk of hearing loss from long-term exposure to loud noise. This includes not having music or the television on at a loud volume at home, and using ear-protection at loud music events or in noisy work environments.
Read more about preventing hearing loss.
Treating hearing loss
The way hearing loss is treated depends on the cause and how severe it is.
In cases of sensorineural hearing loss, there are several options that may help to improve a person’s ability to hear and communicate. These include:
- digital hearing aid
- middle ear implants – surgically implanted devices suitable for some people who are unable to use hearing aids
- cochlear implants – small hearing devices that are surgically implanted inside the inner ear for people who find that hearing aids aren't powerful enough
- lip reading or sign language
Conductive hearing loss is sometimes temporary and can be treated with medication or minor surgery if necessary, but more major surgery may be required to fix the ear drum or hearing bones. If conventional hearing aids don't work, there are some implantable devices for this type of hearing loss, such as a Bone Anchored Hearing Aids (BAHAs).
Read more about treating hearing loss.
Symptoms of hearing loss
While hearing loss is sometimes sudden, it's often gradual and you may not notice it at first. Being aware of the early signs can help you identify the problem quickly.
It's important to spot hearing loss as soon as possible because treatment is often more beneficial if it's started early.
General signs of hearing loss
Early signs of hearing loss can include:
- difficulty hearing other people clearly and misunderstanding what they say
- asking people to repeat themselves
- listening to music or watching television with the volume turned up high
- difficulty hearing the telephone or doorbell
- regularly feeling tired or stressed, due to having to concentrate closely while listening
In some cases, you may recognise signs of hearing loss in someone else before they notice it themselves.
Signs of hearing loss in children
Although babies are routinely screened within the first few weeks of their birth, there are signs you can look out for which may suggest you should see your doctor to arrange another hearing test.
Signs in babies
You should consider seeing your doctor if you notice that your baby or toddler:
- is not startled by loud noises
- does not turn towards the source of a sound while under 4 months old
- does not say single words by the time they are 1 year old
- notices you when they see you but not when you call their name
- hears some sounds but not others
Signs in children
You should consider seeing your doctor if you notice your child:
- is slow to learn to talk, or they're not clear when they speak
- often asks you to repeat yourself
- often talks very loudly
- often turns up the volume of the TV so that it's very loud
Seeking medical help
Make an appointment to see your doctor if you're having problems with your hearing, or your child is showing signs of hearing difficulties.
If you wake up with a sudden loss of hearing in 1 ear or lose the hearing in 1 ear within a couple of days, see your doctor as soon as possible.
Read more about diagnosing hearing loss.
Causes of hearing loss
Age and loud noises are the most common causes of hearing loss.
Age is the biggest single cause of hearing loss. Hearing loss that develops as a result of getting older is often known as age-related hearing loss or presbycusis.
Most people begin to lose a small amount of their hearing when they're 30 to 40 years old. This hearing loss increases as you get older and by the age of 80, most people will have significant hearing problems.
Age-related hearing loss occurs when the sensitive hair cells inside the cochlea (the coiled, spiral tube section of the inner ear) gradually become damaged or die. This type of hearing loss is known as sensorineural hearing loss.
As your hearing starts to deteriorate, high-frequency sounds, such as female or children’s voices, may become difficult to hear. It may also be harder to hear consonants. This can make understanding speech in background noise very difficult.
Another common cause of hearing loss is damage to the ear due to repeated exposure to loud noises over time. This is known as noise-induced hearing loss and it occurs when the sensitive hair cells inside the cochlea become damaged (known as sensorineural hearing loss).
People who're at a particularly risk of developing noise-induced hearing loss include:
- people who work with noisy equipment, such as pneumatic drills or compressed-air hammers
- people who work in environments where there's loud music, such as nightclub staff
- people who regularly listen to music at a high volume through headphones
Hearing loss can also occur suddenly due to an exceptionally loud noise, such as an explosion. This is known as acoustic trauma.
See preventing hearing impairment for advice about reducing your risk of noise-induced hearing loss.
Other types of sensorineural hearing loss
Sensorineural hearing loss occurs if the sensitive hair cells inside the cochlea are damaged, or as a result of damage to the auditory nerve (the nerve that transmits sound to the brain). In some cases, both may be damaged.
Hearing loss caused by age and exposure to loud noises are both types of sensorineural hearing loss.
Sensorineural hearing loss can also be caused by:
- genetic hearing loss – some people may be born deaf or become deaf over time due to a genetic abnormality, although there's not always a family history
- viral infections of the inner ear, such as mumps or measles
- viral infections of the auditory nerve, such as mumps or rubella
- Ménière's disease – where a person suffers with vertigo (spinning dizziness), hearing loss which can come and go, tinnitus and a feeling of a blockage in the ear
- acoustic neuroma – a non-cancerous (benign) growth on or near the auditory nerve
- meningitis – an infection of the protective membranes that surround the brain and spinal cord
- encephalitis – inflammation of the brain
- multiple sclerosis – a neurological condition affecting the central nervous system (the brain and spinal cord)
- stroke – where the blood supply to the brain is cut off or interrupted
Some medications, such as certain chemotherapy medicines and certain antibiotics can also damage the cochlea and the auditory nerve, causing sensorineural hearing loss.
Sensorineural hearing loss is permanent and hearing aids are often required to improve hearing in these cases. Read more about treating hearing loss.
Conductive hearing loss
Conductive hearing loss occurs when sounds are unable to pass into the inner ear. This is usually due to a blockage, such as having too much ear wax, a build-up of fluid in the ear (glue ear), or an ear infection.
Conductive hearing loss can also be caused by:
- a perforated eardrum – where the eardrum is torn or has a hole in it
- otosclerosis – an abnormal growth of bone in the middle ear, which causes the inner hearing bone (the stapes) to be less mobile and less effective at transmitting sound
- damage to the hearing bones from injury, a collapsed ear drum or conditions such as cholesteatoma (an abnormal collection of skin cells inside your ear)
Conductive hearing loss is usually temporary and it can often be treated with medication or minor surgery. Read more about treating hearing loss.
Diagnosing hearing loss
See your doctor if you're having problems with your hearing. They will examine your ears and carry out some simple hearing tests.
During an ear examination, an instrument with a light at the end called an auriscope (or otoscope) is used to look for anything abnormal including:
- a blockage caused by earwax, fluid or an object
- an ear canal infection
- a bulging ear drum – indicating that there is infection inside the middle ear
- fluid behind the ear drum, known as glue ear
- a perforated ear drum – a hole in the eardrum
- a collapsed ear drum
- skin collected in the middle ear (cholesteatoma)
Your doctor will ask you if you have any pain in your ear and when you first noticed the hearing loss.
Referral to a specialist
Your doctor may refer you to an ear, nose and throat (ENT) specialist or an audiologist (a hearing specialist). The specialist will carry out further hearing tests to help determine what's causing your hearing loss and recommend the best course of treatment.
Some of the hearing tests that you may have include:
- a tuning fork test (sometimes performed by your doctor)
- pure tone audiometry
- bone conduction test
Tuning fork test
A tuning fork is a Y-shaped, metallic object. It produces sound waves at a fixed pitch when it's gently tapped and can be used to test different aspects of your hearing.
The tester will tap the tuning fork on their elbow or knee to make it vibrate, before holding it at different places around your head.
This test can help determine if you have conductive hearing loss, which is hearing loss caused by sounds not being able to pass freely into the inner ear, or sensorineural hearing loss where the inner ear or hearing nerve isn't working properly.
Pure tone audiometry
Pure tone audiometry tests the hearing of both ears. During the test, a machine called an audiometer produces sounds at various volumes and frequencies (pitches). You listen to the sounds through headphones and respond when you hear them by pressing a button.
Bone conduction test
A bone conduction test is often carried out as part of a routine pure tone audiometry test in adults. It's used to check if you have sensorineural hearing loss by testing how well your inner ear is working.
Bone conduction involves placing a vibrating probe against the mastoid bone behind the ear. It tests how well sounds transmitted through the bone are heard.
Bone conduction is a more sophisticated version of the tuning fork test, and when used together with pure tone audiometry, it can help determine whether hearing loss comes from the outer and middle ear (conductive hearing loss), the inner ear (sensorineural hearing loss), or both.
Newborn Hearing Screening Programme (NHSP)
After your baby is born, they'll be given a number of routine health checks, including a hearing test, which will be carried out within the first few weeks of your baby's birth.
A test that's commonly used to check a baby’s hearing is the otoacoustic emissions (OAE) test. The test involves placing a tiny earpiece into the outer ear. If possible, it will be carried out while your baby is asleep.
The earpiece emits small sounds and checks for a corresponding "echo" from the ear. If your baby's ear is working normally, the echoes should be produced in a part of the ear known as the cochlea. A computer is used to record and analyse the reaction sounds.
If there's no response, it doesn't necessarily mean that your child has a hearing impairment, although further tests will be needed to determine the cause.
About 15% of newborn babies will need further testing and 1 to 2 babies in every 1,000 will have some level of hearing loss in 1 or both ears.
Levels of hearing loss
Very few people with hearing loss hear nothing at all. There are 4 different levels of hearing loss, which are defined by the quietest sound that you're able to hear, measured in decibels (dB).
If you're mildly deaf, the quietest sound that you can hear is between 21 to 40dB. Mild deafness can sometimes make hearing speech difficult, particularly in noisy situations.
If you're moderately deaf, the quietest sound that you can hear is between 41 to 70dB. You may have difficulty following speech without using a hearing aid.
If you're severely deaf, the quietest sound that you are able to hear is between 71 to 90dB. People who are severely deaf usually need to lip-read or use sign language, even with the use of a hearing aid.
If you're profoundly deaf, the quietest sound that you can hear is more than 90dB. People who are profoundly deaf can often benefit from a cochlear implant. Other forms of communication include lip reading and sign language
Read more about treating hearing impairment, including different types of hearing aids and sign language.
Treatment for hearing loss
How hearing loss is treated will depend on the underlying cause of the condition.
Hearing loss that occurs when sounds are unable to pass into the inner ear, usually due to a blockage, (known as conductive hearing loss) is often temporary and treatable.
For example, wax can be removed by drops, a syringe or suction. Hearing loss caused by a bacterial infection can be treated with antibiotics and surgery can be used to drain fluid that builds up in the ear, repair perforated eardrums, or correct problems with the hearing bones.
But hearing loss caused by damage to the inner ear or the nerves that transmit sound to brain (known as sensorineural hearing loss) is permanent.
This is because once the sensitive hair cells in the cochlea (the coiled, spiral tube inside the inner ear) are damaged, they cannot be repaired and remain damaged for the rest of a person’s life.
If your hearing is impaired, treatment can improve your hearing and quality of life. Some of these treatments are discussed below.
If you have hearing problems, you may be able to wear a hearing aid.
A hearing aid is an electronic device that consists of a microphone, an amplifier, a loudspeaker and a battery. It increases the volume of sound entering your ear so that you may be able to hear things more clearly.
The microphone picks up sound, which is made louder by the amplifier. Hearing aids are fitted with devices that can distinguish between background noise, such as traffic, and foreground noise, such as conversation.
Modern hearing aids are very small and discreet and can often be worn inside your ear.
Hearing aids are not suitable for everyone. For example, they may not be effective if you have profound hearing impairment. Your doctor or audiologist (hearing specialist) will be able to advise you about whether a hearing aid is suitable for you.
If a hearing aid is recommended for you, an audiologist will take an impression of your ear so that the hearing aid will fit you perfectly. The hearing aid will be adjusted to suit your level of hearing impairment. You will also be shown how to use and care for it.
After your hearing aid has been fitted, you'll have a follow-up appointment 3 months later.
If you experience problems using a hearing aid – such as distortion and repeated infections – that can't be corrected by an audiologist, you may benefit from different treatments. An ear, nose and throat (ENT) surgeon will be able to discuss these with you.
Both analogue and digital hearing aids are commonly used. Instead of having moving parts, digital hearing aids contain a very small computer that processes sounds. This enables the hearing aid to be programmed to suit different environments, such as a small quiet room or a large, noisy workshop. Other types of hearing aid may be issued in cases where a medical condition prevents an individual from using behind-the-ear (BTE) hearing aids.
Types of hearing aids
The different types of hearing aids are described below.
Behind-the-ear (BTE) hearing aids
Behind-the-ear (BTE) hearing aids usually have an earmould, which sits inside your ear. The rest of the hearing aid is connected to the earmould, and lies behind your ear.
Some types of BTE hearing aids have 2 microphones that enable you to listen to sounds in the general vicinity, or to focus on sounds that are coming from a specific direction. This can be particularly useful in noisy environments.
Receiver in-the-ear (RITE) hearing aids
Receiver in-the ear (RITE) hearing aids are similar to BTE hearing aids, but the piece worn behind the ear is connected by a wire to a receiver (loudspeaker) located within the ear canal.
This means RITE hearing aids are usually less visible than BTE devices.
In-the-ear (ITE) hearing aids
In-the-ear (ITE) hearing aids are like an earmould. They fill the area just outside your ear canal and fill the opening of your ear canal.
The working parts of the hearing aid are either located in a small compartment that's attached to the earmould, or inside the earmould itself.
In-the-canal (ITC) hearing aids
In-the-canal (ITC) hearing aids fill the outer part of the ear canal and are just visible.
Completely in-the-canal (CIC) hearing aids
Completely in-the-canal (CIC) hearing aids are even smaller and less visible than ITE or ITC hearing aids.
However, they may not be recommended if you have severe hearing loss or frequent ear infections.
Body-worn (BW) hearing aids
Body-worn (BW) hearing aids have a small box containing the microphone. The box can be clipped to your clothes or you can put it inside a pocket. A lead connects the box to an earphone, which delivers sound to your ear.
This type of hearing aid is an option for people with poor dexterity who require a high-powered hearing aid.
CROS hearing aids are recommended for people who only have hearing in 1 ear. They work by picking up sounds from the side that doesn't have hearing and transmitting them to the ear that's able to hear. The sound is sometimes transmitted through wires, although wireless models are available.
BiCROS hearing aids work in a similar way to CROS hearing aids, but they amplify the noise entering the ear that's able to hear. They're useful for people who don't have any hearing in 1 ear and have limited hearing in the other ear.
Bone conduction hearing aids
Bone conduction hearing aids are recommended for people with conductive or mixed hearing loss and who can't wear a more conventional type of hearing aid. Bone conduction hearing aids vibrate in response to the sounds going into the microphone.
They can also sometimes help people with no hearing in 1 ear and normal or mild hearing loss in the other ear.
The part of the hearing aid that vibrates is held against the bone behind the ear (mastoid) by a headband. The vibrations pass through the mastoid bone to the cochlea and are converted into sound in the usual way. They can be very effective but can be uncomfortable to wear for long periods.
Bone anchored hearing aids (BAHA)
A bone anchored hearing aid (BAHA) transmits sound directly to the cochlea by vibrating the mastoid bone. A minor operation is needed to fix a screw to the skull, on which the hearing aid can be clipped on and off. A BAHA is worn during the day and removed at night.
Unlike a bone conduction hearing aid, it's not uncomfortable to wear and is often used for patients with conductive hearing loss, or in some patients who have no hearing in one of their ears.
Some people may benefit from newer types of implantable bone conduction hearing aids that are held onto the head with magnets instead of a connector sticking through the skin. But these types of hearing aid aren't always available on the NHS.
Middle ear implants
These are surgically implanted devices, which attach to the hearing bones and make them vibrate.
They're suitable for people who can't use a hearing aid but have hearing loss at a level where a bone anchored hearing aid wouldn't help.
Disposable hearing aids
Disposable hearing aids are sometimes recommended for people who have mild to moderate hearing loss.
The battery inside a disposable hearing aid usually lasts for about 10 weeks, after which time the hearing aid is thrown away and replaced. Disposable hearing aids tend to be expensive in the long-term and are usually only available privately.
Cochlear implants are small hearing devices fitted under the skin behind your ear during surgery.
They have an external sound processor and internal parts, including a receiver coil, an electronics package and a long wire with electrodes on it (an electrode array).
The external processor takes in sound, analyses it and then converts it to signals which are transmitted across the skin to an internal receiver-stimulator, which sends the signals along the electrode array into a part of the inner ear called the cochlea. The signal is then sent to the brain along the hearing nerve as normal. This means that cochlear implants are only suitable for people whose hearing nerves are functioning normally.
A cochlear implant is sometimes recommended for adults or children who have profound sensorineural hearing loss in both ears, which isn't helped by hearing aids.
Both ears are usually implanted for children whereas adults are usually only able to have one implant on the NHS.
Before a cochlear implant is recommended, you'll be assessed to find out whether it will help improve your hearing. During the assessment, any disabilities or communication problems that you have will be taken into consideration, which may mean that the usual hearing tests are not suitable.
If a cochlear implant is recommended, it will be inserted into your ear (or both ears) during an operation and will be switched on a few weeks later.
Auditory brainstem implants
In some cases of severe hearing loss where there are problems with the nerve that transmits sound to the brain, an auditory brainstem implant (ABI) may be used.
This is a surgically-implanted electrical device that stimulates the fibres of the hearing nerve, once it's entered the brainstem. It's similar to a cochlea implant, but it's used to bypass the cochlea and and hearing nerve, and connect directly to the brain.
An ABI is made up of 3 main parts:
- electrodes implanted in the part of the brain responsible for processing sound
- a receiver device placed under the skin behind your ear
- a small sound processor outside your ear, which captures sound waves and converts them into electrical impulses
When the microphone in the processor picks up sound, it turns it into an electrical signal. The processor then transmits this signal to the brain through the receiver and electrodes.
An ABI will not fully restore your hearing, but it can usually restore some degree of hearing and can make lip-reading easier. It's often used as a treatment for hearing loss associated with a condition called neurofibromatosis type 2 (NF2).
Lip reading and sign language
Sometimes hearing loss can affect your speech as well as your ability to understand other people. Many people with significant hearing loss learn to communicate in other ways instead of, or as well as, spoken English.
For people who experience hearing loss after they've learnt to talk, lip-reading can be a very useful skill. Lip-reading is where you watch a person’s mouth movements while they're speaking in order to understand what they are saying.
For people who are born with a hearing impairment, lip-reading is much more difficult. Those who are born with a hearing impairment often learn sign language, such as British Sign Language (BSL), which is a form of communication that uses hand movements and facial expressions to convey meaning.
BSL is completely different from spoken English and has its own grammar and syntax (word order). Other types of sign language include Signed English and Paget Gorman Signed Speech.
Preventing hearing loss
The ears are fragile structures that can be damaged in many ways, so it is not always possible to prevent hearing loss.
The risk of your hearing being damaged by loud noises depends on how loud the noises are and how long you're exposed to them. Experts agree that continued exposure to noise at or above 85dB (similar to a lawn mower or loud traffic) can, over time, cause hearing loss.
But by following the advice below, it's possible to reduce your risk of noise-induced hearing loss (hearing loss from loud noise).
- don't have your television, radio or music on too loud. This is particularly important if you have young children in the house because their ears are more delicate than an adult’s. If you can't have a comfortable conversation with someone who's 2 metres (about 6.5ft) away from you, turn the volume down. You shouldn't have dull hearing or ringing in your ears after listening to music
- use headphones that block out more outside noise, rather turning up the volume. You can buy add-ons for your existing headphones that block out more outside noise
- use ear protection equipment, such as ear muffs or ear plugs, if you work in a noisy environment. For example a pub, nightclub, a garage workshop or on a building site
- use ear-protection equipment at loud concerts and at other events where there are high noise levels, such as motor races
- don't insert objects into your ears or your children’s ears. This includes fingers, cotton buds, cotton wool and tissue.
- be aware of the symptoms of common causes of hearing loss, such as ear infections (otitis media) and Ménière's disease
- visit your doctor if you or your child are experiencing hearing problems.