Hearing loss

Question 1

Causes of hearing loss in children?

Answer 1

Hearing loss can be congenital, occurring prior to birth, or acquired, as the result of an illness during childhood.

Common Causes

Congenital

Maternal rubella or cytomegalovirus infection during pregnancy
Genetic deafness can be autosomal recessive or autosomal dominant
Associated syndromes, for example Down’s syndrome

Perinatal

Prematurity
Hypoxia during or after birth

After birth

Jaundice
Meningitis and encephalitis
Otitis media or glue ear
Chemotherapy

Question 2

Presentation of hearing loss in childhood?

Answer 2

The UK newborn hearing screening programme (NHSP) tests hearing in all neonates. This involves special equipment that delivers sound to each eardrum individually and checks for a response. This can identify congenital hearing problems early.

Children with hearing difficulties may present with parental concerns about hearing or with behavioural changes associated with not being able to hear:

Ignoring calls or sounds
Frustration or bad behaviour
Poor speech and language development
Poor school performance

Question 3

Purpose of audiometry?

Answer 3

help identify and differentiate conductive and sensorineural hearing loss.

Question 4

Audiogram measurements?

Answer 4

Hearing is tested in both ears separately. Both air and bone conduction are tested separately. The following symbols are used to mark each of these separate measurements:

X – Left sided air conduction
] – Left sided bone conduction
O – Right sided air conduction
[ – Right sided bone conduction

When a patient has normal hearing, all readings will be between 0 and 20 dB, at the top of the chart.

In patients with sensorineural hearing loss, both air and bone conduction readings will be more than 20 dB, plotted below the 20 dB line on the chart. This may affect only one side, one side more than the other or both sides equally.

In patients with conductive hearing loss, bone conduction readings will be normal (between 0 and 20 dB), however air conduction readings will be greater than 20 dB, plotted below the 20 dB line on the chart. In conductive hearing loss, sound can travel through bones but is not conducted through air due to pathology along the route into the ear.

In patients with mixed hearing loss, both air and bone conduction readings will be more than 20 dB, however there will be a difference of more than 15 dB between the two (bone conduction > air conduction).

Question 5

Management of hearing loss in children?

Answer 5

Establishing the diagnosis is the first step. After the diagnosis is established, input from the multidisciplinary team is required for support with hearing, speech, language and learning:

Speech and language therapy
Educational psychology
ENT specialist
Hearing aids for children who retain some hearing
Sign language