Understanding hearing loss

Around 11 million people in the UK have some sort of hearing loss and most of us will notice that our hearing gets worse as we get older.

There are different levels of hearing loss ranging from mild to profound. If you have a mild hearing loss then you might find it difficult to follow conversations, especially in a noisy environment. If you have a profound hearing loss then you wouldn’t hear a jet engine if you were standing right next to it! Most cases of hearing loss cannot be cured but may be treated with hearing aids or a cochlear implant.

There are two types of hearing loss, conductive and sensorineural. It is possible to experience both types of loss at the same time – this is a mixed hearing loss.

Conductive hearing loss

A conductive hearing loss is general loss of volume, where all sounds seems faint or muffled. It is where the ears’ ability to conduct sound from the outer ear through the middle ear into the inner ear is blocked or reduced, often impacting the lower frequencies more significantly.

Conductive hearing loss is caused by problems within the ear canal, ear drum, or the middle ear including the middle ear bones. There is no main significant cause of conductive hearing loss. Where a child is born with a conductive hearing loss the cause is usually genetic or linked to their development in the womb which can include malformation of any part from the outer to middle ear. Causes after birth are wide ranging, they include temporary loss from fluid in the middle ear from a cold, ear infection (middle ear and ear canal), Eustachian tube malfunction, impacted ear wax, perforated ear drum and Otosclerosis.

Sensorineural hearing loss

A sensorineural hearing loss is a loss of specific sound frequencies. This can be limited frequencies or apply to all frequencies. Sensorineural hearing loss is a term to cover two different situations where the loss is caused within the cochlear (inner ear) or is caused by the hearing nerve, the most likely cause is damage or malformation of the cochlear.

Sensorineural hearing loss is most commonly caused by damage to the hair cells within the cochlear in the inner ear. These cells can be abnormal at birth or damaged during your lifetime. Where a child is born with a sensorineural hearing loss the cause is usually genetic or linked to their development in the womb. Causes after birth are wide ranging, they include trauma, presbycusis (age-related loss), overexposure to noise, exposure to sudden extremely loud noises, ototoxic medications, infectious diseases such as meningitis and some genetic conditions.

Testing for hearing loss

To test an adult for any hearing loss an audiologist, may complete a series of tests during an appointment which can also identify the type and potential causes of a hearing loss. Some of the common tests include;

  • Pure tone audiometry. This is the test many people will recognise as a hearing test. You sit in a soundproof room and listen to a series of different sounds usually types of a beep, through headphone and press a button each time you hear a sound. The audiologist via a computer sends the sounds to the headphones and records the response to produce an audiogram a visual picture of your hearing loss showing frequencies and decibel of sound loss. A similar beep test may also be completed using a sound next to the skull behind the ear, this identifies if there is a difference between two types of conduction, air what we can hear normally and bone what we can hear if sounds are transmitted directly through the bones.
  • Speech perception. This test is similar to the pure tone, but speech is listened to rather beeps or other tones. The test is important as a hearing loss may appear significant but your ability to determine speech sounds is good, this information is used in determining any treatment options.
  • This test places a small device is placed in your ear to check for fluid behind your eardrum, it measures a response to changing pressure in the ear. The test can help identify if fluid is causing a conductive hearing loss.

Hearing loss registration

Unlike sight loss, local Councils in England do not have to hold a register of people living in their area who have a hearing loss (although some do choose to do so). In Wales, Councils do need to hold a register of people with hearing loss.