ABOUT THE CONDITION
How does the ear work?
The ear is made up of the outer, middle and inner ear. Sound travels through the outer ear and reaches the eardrum, causing it to vibrate. The vibration passes through three tiny bones (the malleus, incus and stapes) in the middle ear. The vibration then enters the inner ear, where nerve cells produce signals that are carried to the brain, where they are interpreted as sound. See figure 1 for the anatomy of the ear.
Hearing loss
Hearing loss is common and can affect anyone at any age. It is more common in older adults. In children, hearing loss can result from middle ear fluid (glue ear), infections, congenital conditions (present at birth), or illnesses during early childhood. Hearing loss can affect day-to-day life at work, education and socially.
Types of hearing loss
Conductive hearing loss
Problems in the outer or middle ear prevent sound from reaching the cochlea. Causes include:
Sensorineural hearing loss
Damage to the cochlea or auditory nerve. Causes include:
- Age-related hearing loss (presbycusis)
- Noise exposure
- Viral infections
- Medication side effects
- Congenital (present at birth)
Mixed hearing loss
A combination of conductive and sensorineural problems.
How is hearing loss detected?
Hearing loss is usually detected by hearing test (audiogram) and ear pressure test (tympanogram).
Congenital hearing loss
Congenital hearing loss is present at birth. It can be caused by genetic factors, infections during pregnancy (e.g. rubella), or complications at birth. In children, early diagnosis is important for speech and language development.
How is congenital hearing loss detected?
In the UK, newborn hearing screening (otoacoustic emission) is offered to all babies shortly after birth. This quick test helps detect hearing loss early.
How do you find what caused the hearing loss?
- Scans (MRI, CT scan) if abnormalities of the ear or brain are suspected
- Genetic testing in some cases
- Specialist referral for early intervention
How might hearing loss affect me?
Hearing loss often makes it difficult to understand conversations, particularly in noisy places. Many people report that they can hear sounds but struggle to clearly make out words, leading to frustration and feeling left out. Difficulty hearing can begin as early as the 30s, especially with regular loud noise exposure.
Always seek urgent medical advice if you experience sudden hearing loss.
ABOUT HEARING AIDS
Hearing aids amplify sounds to assist people with hearing loss. There are different types of hearing aids available. You will be advised as to which one would suit you best.
External hearing aids
Behind-the-ear (BTE)
This is the most common type. It is suitable for mild to severe hearing loss.
Figure 2. Left BTE hearing aid.
In-the-ear (ITE)
This type of hearing aid is custom fit to the person’s ear canal. It is suitable for mild to moderate hearing loss.
Figure 3. Left ITE hearing aid.
Completely-in-canal (CIC) hearing aid
Tiny and almost invisible; for mild hearing loss. This type of hearing is not generally available on the NHS.
Figure 4 Left CIC hearing aid.
Newer hearing aid technology
- Bluetooth connectivity
- Rechargeable batteries
- Noise reduction
- Directional microphones
- AI-based sound adjustment
You can discuss your options with your audiologist.
Bone conduction band
Bone conduction bands are soft, adjustable headbands that hold a bone conduction processor against the head. They are commonly used in children who are not yet suitable for surgical implants or in adults as a trial device.
Bone conduction hearing aids bypass the ear canal and transmit sound directly to the inner ear, suitable for those with ear or middle ear problems.
Figure 5. Bone conduction band hearing aid.
Implantable hearing aids
The hearing aids described above are portable and worn externally, whereas the hearing devices outlined below require an operation for implantation.
All operations carry risks, and the risks specific to the operation will be discussed by your specialist in detail before proceeding with treatment.
Bone conduction hearing aids
Bone conduction hearing aids transmit sound vibrations directly to the inner ear through the bones of the skull, rather than sending sound through the ear canal as traditional hearing aids do. People tend to benefit from this type of hearing aid if they have problems in the ear canal or middle ear, such as recurrent ear infections, previous surgeries, or congenital abnormalities, which prevent them from using conventional hearing aids.
Types of bone conduction aids:
- Percutaneous - These devices use a small implant that protrudes through the skin. The external sound processor attaches directly to the implant, providing efficient sound transmission.
Figure 6: (a) Skin implant - (b) Sound processor
- Transcutaneous - These systems use magnets or other means to keep the external processor in place, transmitting sound through intact skin. They avoid the need for a permanent skin opening and are associated with a lower infection risk.
Figure 7. (a) Magnet implanted under the skin. (b) Transcutaneous bone hearing aid.
Middle ear implants
Middle ear implants are an alternative for some people who cannot use traditional hearing aids or bone conduction devices. A small implant is surgically attached to one of the middle ear bones. An external audio processor captures sound and sends vibrations to the implant, which then stimulates the inner ear.
This type of hearing solution is not provided in every hospital.
Cochlear implants
Cochlear implants are designed for people with severe to profound sensorineural hearing loss who cannot benefit adequately from hearing aids. A device is surgically implanted into the cochlea. An external sound processor captures sound and sends signals to the implant, which directly stimulates the inner ear.
Figure 8. A left cochlear implant with an external sound processor.
After the operation, patients will need regular follow-up to monitor progress and ensure the device is working properly. Maintenance and troubleshooting support will be provided to address problems.
Ongoing hearing therapy and rehabilitation programme is recommended. This helps patients adapt to their new hearing abilities and optimize the use of their hearing aids or implants.
How can I get a hearing aid?
In the UK, most type of hearing aids are provided free through the NHS. Some people may wish to go privately for hearing aids not provided on the NHS.
Further reading
Disclaimer: This publication is designed for the information of patients. Whilst every effort has been made to ensure accuracy, the information contained may not be comprehensive and patients should not act upon it without seeking professional advice.