Newborn hearing screening
Newborn hearing screening uses a test developed in the UK called the Automated Otoacoustic Emissions Test (AOAE). It followed the discovery in the late 1970’s that for each sound which is heard by the ear, the ear itself produces a tiny corresponding sound, an ‘echo’ known as an otoacoustic emission.
The test involves placing a small ear piece into a baby’s outer ear which produces gentle sounds. The ‘echo’ responses are then measured by a computer and indicate if a baby has a healthy middle and inner ear (cochlea).
The test is performed in the first few weeks of life often before a baby leaves the hospital, but sometimes at home or in a local clinic. It is non-invasive and takes only a few minutes to produce the results. It does not rely on the participation of the baby, so a baby can be asleep.
If the test is conducted and does not show a clear response, a baby will be referred for a second screen. This does not necessarily mean they have a hearing loss as sometimes conditions at the time of the screening are not right; a baby may be unsettled or there may still be fluid in the ear canal from the birth.
If after the second AOAE a baby does not show a clear response they will be referred for a different screening test called the Automated Auditory Brainstem Response Test (AABR). This is also non-invasive and can be performed whilst a baby is sleeping. It may take between five minutes to thirty minutes.
The ABR measures the brain’s activity in response to sounds and involves placing three small sensors on the baby’s head and neck and headphones on the baby’s ears. A series of clicking sounds are then played and a computer records the brain’s response.
In the case where a baby does not have a clear response to the ABR screen, they will be referred to an audiologist for further hearing tests.
What happens if the tests identify a hearing loss??
If a baby is identified with a permanent hearing loss, further tests may be able to identify its cause. For example, many cases of permanent hearing loss will be due to genetic changes that have been passed on from the parents. For more information, see Genetics and deafness.
A baby may then be fitted with hearing aids or if the hearing loss is profound and cannot be helped in this way, they may be a potential candidate for cochlear implantation. For more information, see Cochlear implants.
There are a number of health professionals who work with families where there has been a diagnosis of a permanent hearing loss. As well as audiologists these include teachers of the deaf and speech and language therapists.
Sometimes a baby may be suspected as having a temporary hearing loss caused by a condition such as glue ear. In this case a baby’s hearing may initially be monitored with hearing tests at intervals as this is a condition which can clear up without any intervention. You can order the Deafness Research UK Ear Infections and glue ear in children leaflet for further information.
Who should i contact for more information?
For further information on the Newborn Hearing Screening Programme in England visit the Newborn Hearing Screening Programme website (www.hearing.screening.nhs.uk).
Alternatively for information on the Newborn Hearing Screening Programme in Scotland visit www.nsd.scot.nhs.uk/services/hearing/ and in Wales www.screeningservices.org.uk/nbhsw/
