Sensorineural hearing loss: causes, symptoms and treatment

Hearing depends on sound travelling through the outer and middle ear to the inner ear, where hair cells turn it into signals carried by the auditory nerve to the brain. NHS inform explains that hearing loss is the result of sound signals not reaching the brain. In sensorineural hearing loss the problem lies in the inner ear or the hearing nerve, rather than in the passage of sound through the outer and middle ear.

This is different from conductive hearing loss, which NHS inform describes as sounds being unable to pass from the outer ear to the inner ear, often because of a blockage such as earwax, glue ear, fluid from an ear infection, a perforated ear drum or a disorder of the hearing bones. Conductive loss is sometimes temporary and can be treated with medication or minor surgery. Sensorineural loss is generally permanent, because damaged hair cells and nerve fibres do not regenerate, which is why management focuses on making the most of the hearing that remains.

Hearing loss can occur at any age. The NHS notes that hearing loss is common, particularly as you get older, and that some people are born with it, though most cases develop later.

The NHS says it is not always easy to tell if you are losing your hearing, and that sometimes someone else notices before you do. Common signs include the following.

• Difficulty hearing other people clearly and misunderstanding what they say, especially in noisy places.

• Needing people to repeat themselves.

• Listening to music or watching television with the volume higher than other people need.

• Difficulty hearing on the phone or hearing the doorbell.

• Finding it hard to keep up with a conversation or to tell which direction a noise comes from.

• Feeling tired or stressed from having to concentrate while listening.

• Ringing, buzzing or hissing in the ears (tinnitus), which NHS inform says is often associated with hearing loss.

NHS inform says that sensorineural loss can happen naturally with age or as a result of injury. The NHS table of causes lists gradual hearing loss in both ears from ageing or damage from loud noise over many years, and sudden hearing loss together with dizziness, vertigo or tinnitus from labyrinthitis or Ménière's disease. RNID lists causes of sudden hearing loss including earwax, ear infections, physical injury, medication side effects, acoustic neuromas and Ménière's disease.

Noise exposure is the main preventable factor. NHS inform advises using headphones that block out more outside noise rather than turning up the volume, wearing ear protection in noisy workplaces and at loud events, and not having the television, radio or music on too loud. It notes that it is not always possible to prevent hearing loss caused by an underlying condition.

Treatment cannot normally repair damaged hair cells, so treatment is about improving the ability to hear and communicate. The NHS says that if you have permanent hearing loss, a specialist will often recommend hearing aids, which will not make hearing perfect but make sounds louder and clearer, and some people may need a hearing implant attached to the skull or placed deep inside the ear.

The NHS says to ask for an urgent GP appointment or get help from NHS 111 if you have sudden hearing loss in one or both ears, your hearing has been getting worse over the last few days or weeks, or you have hearing loss along with other symptoms such as earache or discharge from the ear. It might not be anything serious, but it may need to be treated quickly.

RNID says sudden hearing loss can happen instantly or over the course of a few weeks, and that it can be a medical emergency with a very short window for treatment to work. If you cannot reach a GP or NHS 111, go to the nearest A&E; an ENT specialist will carry out tests to find the degree and type of hearing loss.

For gradual change, the NHS advises seeing a GP if you think your hearing is getting gradually worse or has not come back after treatment for an ear infection or earwax. Some pharmacies and opticians offer free hearing tests.

NHS inform says your GP can check for any problems and may refer you to an audiologist (hearing specialist) or an ENT specialist for further tests. Audiologists use hearing tests to measure how well you hear different pitches and volumes, which shows whether the loss is sensorineural, conductive or mixed.

The NHS says treatment depends on what is causing it, and that a GP may be able to treat a cause such as an ear infection or earwax. If the cause is not something a GP can treat, they may refer you to a hearing specialist for tests and treatment.

NHS inform lists signs that should prompt you to see your GP. For babies and toddlers: not being startled by loud noises, not turning towards the source of a sound under 4 months old, not saying single words by the time they are 1 year old, noticing you when they see you but not when you call their name, and hearing some sounds but not others.

For older children it lists being slow to learn to talk or not clear when speaking, often asking you to repeat yourself or responding inappropriately to a question, not replying when called, often talking very loudly, often turning up the volume of the television very loud, and watching other people to copy instructions because they have not heard. The NHS notes that hearing loss can affect a child's speech development and progress at school.

The NHS suggests reducing background noise or moving somewhere quieter when talking, facing people so that you can see their mouth and expressions, asking people to speak more slowly and clearly or write things down, and asking about tools such as telephone and television amplifiers, flashing or vibrating alarms and smartphone apps. It advises wearing ear protection when exposed to loud noise and not putting fingers, cotton buds or other objects in the ears.

The NHS also notes that hearing loss can affect a child's speech development and progress at school, and NHS inform lists signs in babies and children to raise with a GP, such as not being startled by loud noises, being slow to learn to talk or often turning up the television volume. RNID provides communication tips and a free online hearing check.

NHS audiology services provide hearing tests and NHS digital hearing aids after GP referral, and ENT departments assess sudden loss and implants. NHS inform notes that hearing tests are also available on the high street, but you may have to pay for these.

Some people choose private audiologists for faster appointments or a wider choice of devices. For sudden hearing loss, do not wait for a private appointment: use NHS 111, your GP or A&E, because treatment is time-sensitive.