What is conductive hearing loss?

Conductive hearing loss happens when there is a blockage of some kind in the outer or middle ear that prevents sound from properly passing through to the inner ear. You can experience it in one or both ears.

Symptoms of conductive hearing loss

In a similar way to if you were wearing ear plugs, or covering your ears, conductive hearing loss affects the way we perceive sound levels. So you might find it sounds like everything is muffled, or just quieter than normal. 

Other symptoms of conductive hearing loss include:

  • The loudness of the sound diminishes but not the clarity 
  • Trouble hearing conversations
  • Difficulty perceiving quiet sounds
  • Obvious differences in hearing in each ear
  • A feeling of pressure or discomfort
  • A difference in how your voice sounds to you
  • You feel that your own voice sounds different

You’ll find that speech is clear and there’s no distortion, but it just needs to be louder for you to properly hear. 

Flat hearing loss

Flat hearing loss is one type of conductive hearing loss where your test results will show a ‘flat loss’, which means that your hearing is affected at all frequencies.

The symptoms of flat hearing loss include:

  • Not being able to hear low tones, often associated with tinnitus
  • Your own voice sounding very loud

Causes of conductive hearing loss

Conductive hearing loss arises from issues with the middle and outer ear — usually, a blockage of some sort. Issues in the middle ear can often reduce the amount of sound that is able to pass through to the inner ear and onto the brain. The severity of conductive hearing loss depends on how blocked the ear is, but generally speaking, conductive hearing loss tends to be less severe than sensorineural hearing loss.

Common causes of conductive hearing loss include:

Earwax 

The most common cause of conductive hearing loss. When earwax becomes impacted in the ear canal, it can prevent sound from easily passing through. This can be treated by removing the excess wax.

Ear infections

Ear infections can occur in the middle ear (otitis media) or the outer ear (swimmer’s ear). Symptoms can vary, but there is usually a build-up of fluid which causes a temporary reduction in hearing: sounds are usually quite muffled on the side of the infection. In some cases, it’s possible for ear infections to lead to permanent hearing loss, find out more here

Middle ear infections (otitis media) are the most frequently diagnosed disease among infants and young children, with 75% having had it by the time they are three years old.1

Foreign bodies

This is more commonly seen in children. If there is a foreign object stuck in your ear, do not attempt to remove it yourself: seek medical help to prevent it from being pushed further inside. 

Fluid in the ear

Fluid in the ear tends to be a reaction to minor ailments like hay fever and the common cold. It typically resolves as the ailment itself improves.  — when there is a hole in your eardrum, rather than a blockage. 

This reduces the clarity of sound being transmitted to the brain, therefore making it harder for you to hear. 

Other causes

  • Perforated eardrum — a tear or hole in the eardrum
  • Ear malformation — Congenital abnormal development can lead to structural defects of the outer and middle ears that lead to conductive hearing loss in children
  • Eustachian tube dysfunction — a condition that affects the tubes connecting the ear to the throat
  • Abnormal growths — non-cancerous growths can sometimes develop in the ear canal, which makes it much narrower and more likely to cause obstructions. These are commonly present at birth or develop from repeated ear infections
  • Otosclerosis — The hardening of the middle ear structure, or otosclerosis, affects about 1% of the population. Surgery can usually correct this condition; you can find more information on this further down the article.

Diagnosis for conductive hearing loss

Due to the variety of potential causes, conductive hearing loss might be diagnosed by either a GP or an audiologist.

They’ll ask you about your hearing loss and about any other symptoms you might have, as well as your history. They will also examine your ears and check for any signs of infection, damage or blockage in the ear using an instrument called an otoscope.

They might also choose to carry out an audiogram and tympanogram. An audiogram tests for hearing loss, whereas a tympanogram tests the pressure within the ear by measuring how mobile the eardrum is. If there is a change in the pressure, then it will affect how the sound is conducted through the ear. 

In a similar way to diagnosing sensorineural hearing loss, some tests will be conducted using a tuning fork, known as the Weber and Rinne tests.

Treatment for conductive hearing loss

Most cases of conductive hearing loss are temporary and generally can be sorted out by treating the underlying condition. For example, removing the foreign body from the ear, taking antibiotics or medication for an ear infection, or clearing away impacted earwax may be all it takes to restore hearing — you can book an earwax removal appointment here.

In some cases, people may benefit from wearing hearing aids to amplify quiet sounds. There is also a surgical option for some people to treat their conductive hearing loss, for example if it is due to a growth in the ear canal. 

If you’re prone to ear infections and they are a recurring issue, as often happens in children, your doctor may offer you a type of surgery where a small tube (known as a grommet or pressure equalisation tube) will be placed across the eardrum to help fluid drain from the middle ear to the eardrum and help prevent build-up.

Causes of hearing loss
Symptoms of hearing loss
Sensorineural hearing loss
References
  1. Le saux N, Robinson J.L., Management of acute otitis media in children six months of age and older, Paediatr Child Health, 2016;21(1):39-50.