Newborn hearing screening

Newborn hearing screening is the name given to a type of screening test that tests the hearing of newborn babies within the first weeks of life.

As of March 2006, all babies in England are now being screened for hearing problems within a few days of birth as the NHS Newborn Hearing Screening Programme in England completes its roll out.

The National Deaf Children's Society campaigned for screening to be introduced for many years, and now provides information for parents about screening and childhood deafness on behalf of the NHS in England, Wales and Scotland, and the Department of Health, Social Services and Public Safety (DHSSPS) in Northern Ireland.

The screen uses two quick and simple tests to see if there is a need for further investigation. These are called the Otoacoustic Emissions test (OAE) and the Automated Auditory Brainstem Response test (AABR). Both tests are painless for the baby.

The OAE test works on the principle that a healthy cochlea will produce a faint echo when stimulated with sound. A small ear-piece, containing a speaker and a microphone, is placed in the baby’s ear. A clicking sound is played and if the cochlea is functioning properly the ear-piece will pick up the echo. This is recorded on a computer that tells the screener if the baby needs to be referred for a further screening test. If the test records strong responses from the baby’s ear then they will not need any further tests.

The screening test is very quick and gives the result immediately. Being referred for further a screening test doesn’t necessarily mean that the baby has a hearing loss. It can be difficult to get a response if the baby was unsettled at the time of the test, if the room was noisy or if there is any fluid in the ear from the birth process. The test is usually repeated before referral for the second type of screening test.

The AABR screening test works by recording brain activity in response to sounds. Sound travels through the outer ear as vibrations. When it reaches the cochlea it is converted into an electrical signal. This travels along the nerve of hearing to the brain where it processed into recognizable sounds.

he AABR test does this by playing a series of clicking sounds through headphones that cover the baby’s ears. Three small sensors are placed on the baby’s head and connected to the computer equipment. If the hearing system is working normally then the computer will report strong responses. If there is no strong response then the computer will report that a referral should be made.

The vast majority of babies will show strong responses after the OAE screening test. Around 15% will be referred for the AABR screening test. Around 3% will go onto the next stage.

This involves a full diagnostic assessment in the audiology department. One to two babies in every 1000 born will have some level of hearing loss in one or both ears.

Where will the screening test be done?

The majority of areas will provide the screening test as part of maternity care in hospital. The test will generally be carried out by specially trained hearing screeners. Some areas will offer the screen in community clinics or at home. This will be done by health visitors or hearing screeners.

Why do we need a new screen for deafness?

The previous screening test used for hearing in babies is called the Health Visitor Distraction Test (HVDT) or Infant Distraction Test (IDT). Babies were usually screened at 7 or 8 months old.

The test involved a health visitor watching to see if the baby would respond to a sound from an unseen source. One problem with this test was that the child could use other senses to ‘pass’ the test. For example the health visitor may have been wearing perfume which the child could smell, or the child may have seen a shadow. Another disadvantage of this test is that the baby needs to be old and strong enough to turn towards the sound made by the health visitor.

Research showed that the effectiveness of this screening test varied. As a result, deaf children were often identified late. Fifty per cent of children with a permanent hearing loss were not identified until 18 months old. Twenty-five per cent were not identified by three and a half years old.

The major problem with late identification is the effect on language development. A delay in identification can mean a delay in establishing effective communication with the child. This in turn can have a long-term impact on their social and educational development.

Research undertaken in the USA has shown that a deaf child can develop language at the same rate as their hearing peers if:

• deafness is identified by the age of six months; and

• a good early intervention and support programme is provided.

Up until the Newborn Hearing Screening Programme, many areas across the country provided targeted hearing screening for newborn babies. A number of high risk criteria were used to select babies that required hearing screening. They had the screening test soon after birth, usually before leaving hospital. The criteria included:

• a family history of deafness

• cranio-facial abnormalities

• exposure to drugs which damage the hearing system

• spending more than 48 hours in a Neonatal Intensiver Care Unit (NICU) or Special Baby Care Unit (SBCU)

However, 30% to 40% of deaf babies have no known risk factors and were therefore not tested. It is widely acknowledged by professionals working in the field that many deaf babies slipped through the net with the previous screening tests.

As 90% of deaf babies are born into families with no history of deafness, this early support is vital. The majority of parents have no experience of deafness. Early identification, followed by a good early intervention programme can make the process easier for the family and lead to better outcomes for the child. The early intervention can involve a range of professionals, including audiologists, teachers of the deaf, and speech and language therapists. It can also include contact with other parents and deaf adults. 

Newborn Hearing Screening Programmes (NHSPs) are being introduced around the UK. In England the NHSP has been running since December 2001. In the first year 22 areas of the country began screening all newborn babies. Newborn Hearing Screening is now available to all newborn babies in England.

Scotland, Northern Ireland and Wales also began Newborn Hearing Screening after 2001.

The Department of Health worked with the National Deaf Children’s Society to produce a series of leaflets for parents of newborn babies going through the screening process in England. These leaflets have also been adapted for Scotland and Northern Ireland. Booklets were also produced for parents whose babies were identified as deaf through the screening programme.

The leaflets and booklets were written in consultation with parents and professionals. The  leaflets have two main aims:

• to provide parents with the information that they will need to make informed choices about the screening, and
• to provide clear and accessible information about each stage of the screening in order to minimise the anxiety felt by parents.

The booklets also have two main aims:

• to support the information given to parents by the audiologist at the the time of the identification of deafness. This can be an extremely emotional time for parents and information  can be difficult to take in and remember. The booklets can help parents remember this information.
• to make parents aware of some of the sources of support that are available to them.