The early detection of hearing loss, and the initiation of medical and educational interventions, has been demonstrated to significantly improve long-term outcomes for children with hearing loss and their families. Early identification, via universal new-born hearing screening gives babies a better ‘life chance' of developing speech and language skills and of making the most of social and emotional interaction from an early age. While the detection of early hearing is vitally important to a child’s development, it also means that support and information can be provided to parents at an early stage.
Goals of the Universal New-born Hearing Screening Programme
The core objectives of the Universal New-born Hearing Screening Programme are described as “1-3-6‟ goals which are based on international standards:
- Babies to be screened by 1 month of age
- Diagnostic audiology assessments completed by 3 months of age
- Initiation of appropriate medical and audiological services, and Early Intervention services, by 6 months of age.
All babies born in Ireland are now offered a new-born hearing screen , ideally before they go home from hospital. A trained Screener carries out an automated hearing screen, usually when the baby is asleep at the Mother’s bedside. Babies discharged before the screen can be offered an appointment to complete the screen in an Outpatients Clinic.
On average 5,000 babies are screened in Ireland every month. Approximately 3% of these babies do not pass the hearing screening and will be referred to Audiology for a diagnostic assessment. One to two babies in every 1,000 will be diagnosed with a hearing loss in one or both ears. Early detection of hearing loss and the initiation of intervention and support gives these babies a better chance of developing age appropriate speech and language skills.
Universal newborn hearing screening seeks to identify all babies born with a congenital, unilateral or bilateral, moderate to profound Permanent Childhood Hearing Impairment (PCHI) before the baby is three months old.
Background to the Universal New-born Hearing Screening Programme
On behalf of the HSE, Northgate Public Services first introduced Hearing Screening in the South and South East in 2011, becoming a National programme in November 2013 when the programme was rolled out Nationwide. Hearing screening is available in all maternity hospitals and to all home birthed babies in Ireland. Using innovative technology, the Screener can run the automated hearing screen when the baby is asleep. There are two types of hearing screens and a baby may have one or more screens. Each stage is explained by the Screener.
Tests in the Universal New-born Hearing Screening Programme
For the initial hearing screen, called an automated oto-acoustic emission or AOEA, the Screener places a small soft tipped earpiece in to the outer part of your baby’s ear. Clicking sounds are sent down the ear. When an ear receives sound, the inner part, known as the cochlea, usually produces an echo. The screening equipment can pick up this echo.
An oto-acoustic emission (OAE) or “echo” is the response arising from a healthy ear in response to a sound being presented and would indicate that the hearing is satisfactory. This screen can be repeated if a clear response is not achieved in either one or both ears.
The hearing screen test does not hurt and is not uncomfortable. The screening test will usually be done while a baby is asleep or settled.
If after the second automated oto-acoustic emission (AOAE) a baby still does not show a clear response, they will have the second test called automated auditory brainstem response (AABR). This measures activity in the auditory nerve and brainstem in response to sounds. The Screener places three small sensors on your baby’s head and neck. Soft headphones, specially made for babies, are placed over your baby’s ears and a series of clicking sounds are played. The hearing screening equipment measures how well your baby’s ears respond to sound. This screen is not repeated and is the last screen to take place.
Infants, who have had a period in the Neonatal Intensive Care Unit of greater than 48 hours, automatically have both AOAE and AABR screening tests as there is a higher incidence of hearing loss arising in this population.
Where a baby does not achieve a clear response to the hearing screen, they will be referred to a paediatric audiologist for diagnostic hearing tests and seen typically within four weeks from referral. Even if this happens, it doesn't necessarily mean your baby has a permanent hearing loss.
What are the outcomes of the hearing screening?
There are two possible screening results:
- Clear Response: this means your baby is hearing well today
- No Clear Response: this means a pass result was not obtained and further testing is needed
What does a clear response pass indicate?
A clear response result means that your baby is hearing well today and you will be discharged, unless there are any risk factors identified.
Before the Universal New-born Hearing Screening Programme commenced in Ireland, babies had their hearing assessed by the Public Health Nurse (PHN) using the infant distraction test (IDT) at nine months of age. This relied on babies responding behaviourally to sounds (turning to their source) made by the PHN, whilst being distracted. This test is no longer used as new born hearing screening provides an earlier and more accurate hearing screening.
Hearing can change in some cases and children can develop hearing loss later in childhood. A Childhood Hearing Checklist is given to parents; this enables the parent to monitor milestones and development by age. It is important to have your child's hearing checked if you ever have concerns about his or her hearing or speech and language development in the future.
Why do babies not pass/ fail the universal new-born hearing screening?
There are several reasons why a baby may not pass their hearing screening:
- Baby may have fluid or a temporary blockage in the ear after the birth. This is very common and will pass with time.
- There may have been background noise when the screening test was carried out
- Baby may have been unsettled at the time of screening
- Permanent Hearing loss
It is VERY important to take your baby to his or her follow-up hearing testing appointments even though most babies will be found to have satisfactory hearing. Sometimes not passing hearing screening is an indication of permanent hearing loss. Attending the follow-up appointments is the best way to be SURE about your baby's hearing.
Who provides the hearing screening?
The objective, ear-specific automated hearing screening tests are performed by trained new-born hearing Screeners. The test is usually performed before a baby leaves the hospital, but sometimes an outpatient appointment for the screen is required.
Who provides the follow up hearing tests?
Diagnostic hearing assessments are performed by Paediatric Audiologists.
Can the diagnostic tests be performed immediately after the screening?
Parents ask why the diagnostic appointment does not happen right after the hearing screening.
Although we understand that it can be difficult to wait, we recommend that babies are at least four weeks old for ABR assessment because:
- Some research has shown more accurate ABR assessment results when babies are at least four weeks old.
- If your baby has fluid or debris in the ears from birth, waiting a few weeks gives the ears a chance to clear.
- After four-six weeks you are more familiar with your baby’s feeding and sleeping patterns, we find that babies are more easily settled to sleep in the clinic which is important for the ABR assessment.
What happens at the diagnostic test?
The diagnostic hearing test(s) performed by the audiologist will depend on whether a baby had more than 48 hours in the National Intensive Care Unit or not and whether there are any risk factors that have been identified.
The audiologist will take a history, outline the hearing tests and answer any questions that you may have first.
Typically the audiologist will perform the Oto-acoustic emission test, which is very similar to that used for the automated oto-acoustic emission (AOAE). This test requires the infant to be relaxed and quiet.
Depending upon the outcome of this test and any associated risk factors, the audiologist may need to perform further hearing test, including tympanometry and auditory brainstem response (ABR) testing:
Tympanometry is a test of middle ear function. A small ear-tip is placed in the ear canal and tests the mobility of the eardrum.
Auditory Brainstem Response
The auditory brainstem response (ABR) assessment takes longer than hearing screening because it identifies babies who have hearing loss and provides detailed information about your baby’s hearing levels. This assessment is safe and does not hurt your baby. It can only be accurately performed while your baby sleeps.
You will sit with your baby in a comfortable chair during the testing. The ABR assessment is scheduled for two to three hours, which includes time for you to feed your baby and help your baby fall asleep.
Please be prepared to feed your baby in the clinic during the appointment.
Your baby is prepped for the ABR assessment, by cleaning the skin for the sticky sensors that are placed on babies head, one on the forehead and one behind each ear. Sounds are played through earphones that fit inside your baby’s ears, or where required using a vibrator held in place at the back of the ear. The sensors detect how your baby’s ears and brainstem respond to sounds.
The length of the assessment will depend upon the baby staying asleep during the assessment and the results of the hearing measurements.
In most cases the results of the ABR assessment will be explained to you immediately after the test, occasionally however babies will require further assessment to complete the hearing measurements.
It is important to keep your ABR assessment appointment to find out exactly how your baby hears. Sometimes it takes more than one appointment to accurately assess a baby’s hearing.
What can I do to make the appointment successful?
The ABR assessment can only happen while your baby is sleeping. It is important that you bring your baby to the appointment awake but ready to fall asleep in the clinic. Try to keep your baby awake for at least 1 hour before the ABR assessment.
- Try to delay feeding your baby for at least 1½ hours before the ABR assessment. You may feed your baby in the clinic during the appointment.
- If you are driving to the appointment, have an extra adult in the car to play with your baby and keep him or her awake.
- Bring any special blankets or items that may help your baby sleep.
There are no supervised play areas in the hearing clinic. If you need to bring other children with you, please bring another adult to look after them.
What are the outcomes of the diagnostic hearing assessments?
If a baby has a satisfactory diagnostic assessment result and does not have any risk factors for hearing loss no further testing is needed and you will be discharged from the Universal New-Born Hearing Screening programme.
If a baby is found to have satisfactory hearing (or a temporary conductive loss) and has one or more risk factors for hearing loss the audiologist will automatically wait list your child for a review hearing test, the targeted follow up for nine months of age.
If an infant is found to have a permanent hearing loss, the Paediatric Audiologist will explain the degree of deafness and discuss appropriate management options with the family. These may include the fitting of hearing aids or cochlear implants and the provision of early intervention support. They will provide you with a copy of the “Understanding Childhood Hearing loss” brochure and agree with you regards to onwards referrals to specialists to support the family and child, including Visiting Teacher of the Deaf, Paediatrician, ENT Consultant, DeafHear, Audiology Habilitation.
Parents will be offered hearing aids, where appropriate, and impressions can be taken to start the hearing aid fitting process when parents are ready to proceed.
Universal New-born Hearing Screening Outcomes
The birth rate in Ireland is between 72,000-75,000 babies annually and with an estimated prevalence of hearing loss of approximately 1-2/1,000; there are 70-140 children who will be diagnosed with a hearing impairment each year following universal new-born hearing screening.
The screening programme sees an average of 5,000 babies every month and employs approximately 100 staff. Since its deployment, there have been over 200,000 babies screened and nearly 400 babies diagnosed with a permanent childhood hearing loss (Figures as at April 2016). These children have been able to access early intervention in order to maximise their speech and language development.
Hearing aids are offered as soon as a hearing loss is identified are provided for children
Late Onset Hearing Loss
The Universal New-born Hearing Screen will identify congenital hearing loss within the first few weeks of the infant’s life and enable appropriate support to be provided to ensure the best outcomes for the child.
There is evidence that hearing impairment increases through the first decade of childhood. The reasons for this are varied including meningitis, measles and other causes of acquired impairment; progression of unilateral to bilateral impairments; and late onset/ progressive impairments linked to prenatal or perinatal infection or to hereditary factors.
Risk factors for late onset hearing loss include a range of identified conditions, syndromes, family history and medications that increase the risk of late onset and progressive hearing loss, these are listed below.
Risk Factors for Hearing Loss
- Including Downs, Waardenburg, Treacher-Collins, Goldenhaar, Alport, Usher, etc
- Head and neck malformations e.g. Cleft lip and palate, deformed pinnae (not isolated ear tags)
- Confirmed or suspected congenital infection
- BOTH ears despite clear responses on automated auditory brainstem response (AABR).
For babies that pass the Universal New-born Hearing Screen but have one or more of the above risk factors listed for which there is a possibility of progressive or delayed onset hearing loss, infants are offered at least one audiology assessment by the time they are approximately eight to nine months of (corrected) age. This is termed a targeted follow up (TFU). Further assessment / management will be dependent upon the clinical assessment.
After their child’s Universal New-born Hearing Screen parents are provided with checklists in order to help them make informed observations about their child’s hearing through infancy. If parents have any concerns regarding their child’s hearing and speech development, they should discuss with their Public Health Nurse (PHN) or General Practitioner (GP) in the first instance.
 Babies who are Not Eligible for UNHS include: a)Those born with congenital atresia, b) Those who contract meningitis prior to screening being offered., c) Babies who have a prolonged period in Special Care Baby Unit, greater than 3 months. d)Babies receiving palliative care (in these cases the decision to screen or not is for the parents in discussion with the neonatologist).These infants will be referred to the local audiology service for diagnostic hearing assessment, as and when appropriate by the hearing screening team or the child’s paediatrician or neonatologist