Newborn hearing screening

Newborn babies can be screened for any potential hearing problems using two quick and painless tests. The tests are normally conducted on the ward before you leave hospital. They are the:

• automated otoacoustic emissions (AOAE) test asoft earpieceis placed in your baby's ear and quiet clicking sounds are played through it; the earpiece picks up the response from the inner ear and a computer analyses the results
• automated auditory brainstem response (AABR)test three small sensors are placed on your baby's head and neck, andsoft headphones are used to playquiet clicking sounds; the sensors detect how your baby's brain and hearing nervesrespond to the sound and a computer analyses the results

Many babies will only need to have the AOAE test, but if it's not possible to get a clear result, or there is a possibility they have a problem with their hearing, they may need to have an AABR test as well.

It's common forbabiesto have a second screening hearing test. This doesn't necessarily mean they havea hearing problem. It may be offered because your baby was unsettled during the first test, or they mayjust havea temporary blockage in their ear.

If the results are inconclusive or concerns are raised during the screening process, a referral will be made for a more detailed assessment with your local audiology service.

These areusually undertaken at an audiology department.

Some of the main testscarried out are described below.

Visual reinforcement audiometry

Visual reinforcement audiometry (VRA) is usually used to test hearing in children from approximately seven months of age up to two-and-a-half years old.

During the test, your child will sit on your lap or a chair while sounds are presented. Your baby will be taught to link the sound to a visual reward such as a toy or computer screen lighting up.

Once your child is able to associate the sound and the visual reward the volume and pitch of the sound will be varied to determine the quietest sounds your child is able to hear.

Play audiometry

Young children between two and five years old may have a play audiometry test.

During the test, sounds will be played through headphones or speakers and your child will be asked to perform a simple task when they hear the sound. This may vary from putting a ball in a bucket to completing a puzzle.

As with VRA, the volume and pitch of the sound will be varied to determine the quietest sounds your child is able to hear.

Pure tone audiometry

Older children may have a test called pure tone audiometry. This is the test often used to screen a child's hearing before they start school, when it is sometimes referred to as the "sweep test". It's similar to a hearing test an adult might have.

During pure tone audiometry,amachine generates sounds at different volumes and frequencies. The sounds are played through headphones and your child is asked to respond when they hear themby pressing a button.

Bychanging the level of the sound, the tester can work out the quietest sounds yourchild can hear.

Bone conduction test

In addition to using speakers or headphones, most of the tests above can also be carried out using a small vibrating device placed behind the ear.

This devicepasses sound directly to the inner ear through the bones in the head, which can helpidentify which part of the ear isn't working properly ifyour child is having hearing problems.

Speech perception test

Speech perception tests assess your child's ability to recognise words.

This can be performed in a variety of ways depending on your child's age and ability. Some may be performed using voice and others may involve playing speech through headphones or a speaker. The child may need to identify words they hear by pointing at a toy, picture, or repeating what they hear.

Tympanometry

Tympanometry is atest to assess how flexible the eardrum is.

For good hearing, your eardrum needs to be flexible to allow sound to pass through it. If the eardrum is too rigidfor example, because there is fluid behind it( glue ear ) sounds will bounce back off the eardrum instead of passing through it.

During the test, asoft rubber tube will beplaced at the entranceof your child'sear.Air isgently blown down the tube and a sound is played through a small speaker inside it. The tube then measures the sound that's bounced back from the ear.