Tag Archives: senses

Newborn hearing screening

The newborn hearing screening will be done within the first few days of birth. It has been available to all babies since 2006 and over 6 million babies have been screened since then. It was the National deaf childrens society that pushed for the tests on all children, here is what is involved:

What is involved?

There are two simple and basic tests that can quickly highlight if there is any need for any further investigation, these are usually done on the maternity ward by trained hearing screeners but, on some occasions may be offered at home or at a clinic. The two tests are called the Otoacoustic Emissions test (OAE) and the Automated Auditory Brainstem Response test (AABR). These are both painless for baby.

What is the Otoacoustic Emissions test (OAE) and how does it work?

The OAE test is the first hearing screening your newborn will be subject to. A small ear piece consisting of a microphone and speaker are placed in baby’s ear and a clicking sound played. If the ear is functioning properly the microphone will pick up the faint echo produced by the cochlea (inner ear). The results are immediate and recorded on a computer for the screener to analyse. On some occasions it is necessary to refer for a second test, this doesn’t necessarily mean your child has a hearing problem, it may have been inconclusive or the test failed for a number of different reasons such as a noisy room or fluid in the ear. If the results of this test are fine there will be no need for further investigation. The second test is the Automated Auditory Brainstem Response test (AABR). approximately 15% of babies are referred for this test.

What is the Automated Auditory Brainstem Response test (AABR)?

The AABR test records your baby’s brain activity in response to sounds. This is done by attaching 3 sensors on to your child’s head and playing clicking sounds through headphones. The sensors record if there is a strong response in brain activity as would be expected. The reason a strong response of brain activity is expected is because of the way ears work; sounds travel as vibrations through the outer ear to the cochlea where they are then converted in to an electrical signal. The electrical signal is sent to the brain via the hearing nerve, thus producing an increase in brain activity in response to sounds. If no activity is detected, your baby will be referred for a full diagnostic of hearing. Around 3 out of every 100 children are referred for this.

A full diagnostic

if your child hasn’t shown strong responses to the two tests as detailed above, she will be referred for a full diagnostic assessment of her hearing. This will usually take place at your local audiology department.
The diagnostic assessment will include tympanomenty and Auditory Brainstem Response (ABR) testing. Tympanometry tests how the eardrum and middle ear are working. This test is important because fluid or other problems in the middle ear can affect hearing. During a tympanogram test, a small earphone is placed in the ear canal and air pressure is gently changed. This test is helpful in showing if there is an ear infection or fluid in the ear.

If at any point you become concerned about your child’s hearing, you should contact your GP immediately. If your child is bring investigated, be sure to attend the appointments, the quicker a diagnosis is made, the quicker remedial actions can be put in place. It your child has hearing problems, it is unlikely you can change that, however, through quick diagnosis you will be able to support your child to live with the hearing loss (however severe) and ensure the impact of this is as minimal as possible (such as speech and language delays).

What can my baby see?

Your babies vision improves drastically within the first 8 months of life. If you have ever wondered what and how far your little one can see and when you can expect improvements, then you should look no further:

What do newborns see?

Typically, you will be told your newborn can focus 10-12 inches away, just enough to see Mummy’s face whilst she feeds. Whilst this isn’t wholly inaccurate – it isn’t completely accurate either. When your little one is born, she is capable of fully focusing on any object that is both near or far, however, there are special muscles in our eyes called ciliary muscles which automatically contract or relax to enable your eye to focus properly on any given object; whilst these muscles are developing your newborn is unable to consistently focus with accuracy. By about 2 months of age, these muscles should have developed well enough to improve focus but your little ones brain and retina still need to develop to enable clear, accurate vision; the retina has over 100 million cells in each eye and the part of of the eye responsible for clear vision (called the fovea) takes longer than the lens to mature and work properly. So, even though at 2 months old your baby’s eyes can focus properly, the image projected onto the retina that then falls onto the fovea is still quite blurry. It is said that this blurriness caused by nervous system immaturity’s results in baby’s vision being six times worse than an adults. (If an adult has 20/20 vision, a newborn has 20/120 – if she could read, she could manage the top letter of an eye test). – This obviously means your baby has a rich visual world and more importantly can see your eyes, lips, hair, her own hands, fingers, feet and toes. This is probably why parents are told your baby can focus 10-12 inches away.

Are black and white toys best?

Babies are naturally attracted to high contrasting colours and you can’t get much higher than 100% contrast (black and white). The fact is baby’s colour vision is much better than most people seem to think; in the first month of life, newborns can distinguish between two shades of grey that differ by only 5% (5% contrast). By 2 months they can distinguish between two shades of grey with a 0.5% contrast. Your baby will enjoy and be attracted to black and white toys/mats etc but in terms of helping your child’s visual development, they make no difference at all. In fact, giving your child a break from high contrast colours and patterns may be a good idea once in a while to allow her to explore other, more interesting things such as your face and her hands etc.

When can they see colours?

Babies colour vision isn’t as rich or as sensitive to colours as an adults as the fovea (again) still needs to develop. It is unlikely that babies will be able to distinguish between similar colour differences such as pastel colours or red and reddish orange for example. It is thought that children as young as 2 weeks old have colour vision that can distinguish between 2 different colours.

When will my baby recognise my face?

Being able to see your face and recognising your face are obviously 2 very different things. A tend to look at and pay attention tontine borders of objects such as your hair. At around 2 months of age, this changes and your baby will begin to focus more on your internal features such as your lips, eyes and nose. Around 4 or 5 months, your little one will be able to recognise and distinguish you from every other person in the world.

Resources: ski.org