Mixed hearing loss: causes, tests and treatment options

Sound travels through the outer ear and ear canal to the eardrum, across the middle ear bones, and into the cochlea in the inner ear, where hair-like cells send signals along the hearing nerve to the brain. Birmingham Women's and Children's NHS Foundation Trust describes how anything that reduces or prevents the sound signal before it reaches the brain causes some degree of hearing loss.

Conductive hearing loss arises from a problem in the outer or middle ear and may be temporary or permanent. Sensorineural loss arises when the cochlea or hearing nerve is not working properly and is generally permanent. When the two occur together, it is called mixed hearing loss. NHS inform describes it as having both types of hearing loss.

The NHS lists common signs of hearing loss as difficulty hearing other people clearly, especially in noisy places, needing to ask people to repeat themselves, turning the TV or music up louder than others need, difficulty hearing on the phone, and finding it hard to keep up with a conversation. Feeling tired or stressed from the effort of listening is also described.

UCLH notes that in mixed loss, symptoms and possible causes may be a mixture of those from sensorineural and conductive loss. Conductive features can include muffled hearing, a feeling of fullness in the ear, pain or tenderness, a discharging ear, or balance problems. Sensorineural features include lack of clarity when listening to speech, problems following conversations and problems hearing in noisy places.

UCLH lists possible causes of the conductive component such as a foreign body or wax blocking the ear canal, fluid in the ear, an ear infection, a hole in the eardrum, problems equalising pressure, abnormal growth or formation of the ear, damage to the ear bones and failed ear surgery. NHS inform adds glue ear and disorders of the hearing bones.

For the sensorineural component UCLH lists the natural ageing process, exposure to loud noise over a long period, genetic factors, infections such as meningitis or measles, injury to the ear or head, tumours such as acoustic neuromas, medicines that may harm the hearing system, disease of blood vessels and immune system conditions. NHS inform says sensorineural loss can happen naturally with age or as a result of injury.

A common real-life example is someone with age-related sensorineural loss who develops earwax blockage or an ear infection. The temporary conductive problem makes things noticeably worse until it is treated.

A GP will look in the ear and may treat earwax or infection first, because the NHS says that if hearing has not come back after treatment for an ear infection or earwax build-up you should return. If the cause is not something a GP can treat, they may refer you to a hearing specialist for tests.

Audiology tests, as UCLH explains, are followed by the audiologist explaining the results and their implications, including the type of hearing loss you have. The pages read for this guide do not describe the individual tests in detail, but in general terms a hearing test compares hearing through the air with hearing conducted through the bone, which is how the conductive and sensorineural parts are separated.

The NHS says treatment depends on the cause. A GP may be able to treat the cause, for example antibiotics for an ear infection or ear drops or removal for earwax. If hearing loss is permanent, a specialist will often recommend hearing aids, which make sounds louder and clearer but will not make hearing perfect. Some people may need a hearing implant, which is attached to the skull or placed deep inside the ear.

NHS inform says that for sensorineural hearing loss there are several options, including digital hearing aids available through the NHS and bone anchored implants suitable for people unable to use hearing aids. In mixed loss, the plan often combines treating the conductive element where possible with amplification for the sensorineural element, which your audiology and ENT team will tailor to the test findings.

The NHS suggests reducing background noise, facing people when they speak so you can see their mouth and expressions, asking people to repeat themselves, speak more slowly and clearly or write things down, using devices such as telephone and television amplifiers or flashing alarms, and wearing ear protection around loud noise. It advises not to put fingers or objects such as cotton buds in the ears.

NHS audiology and ENT services assess and fit hearing aids free of charge in most areas of the UK. Some people use private audiologists or high-street providers for faster appointments or different device choices; for mixed loss it is sensible to have a medical ear examination first, so that a treatable conductive cause is not missed.