How common are hearing problems in preemies?At birth, moderate to severe hearing impairment occurs in about three per 1000 infants born on time, but in about three per 100 (3%) of high risk infants. High risk factors include:
- Birth weight under 1500 grams (3lb 5oz), especially those with IVH or PVL
- Family history of childhood hearing loss
- Viral infection present at birth
- Any abnormality in the formation of the face or the ear
- Very high bilirubin levels necessitating exchange transfusion, see Bilirubin
- Infection of the fluid surrounding the brain, called meningitis
- Severe lack of oxygen near the time of birth
How will I know if my baby has a hearing problem?Many nurseries screen babies for hearing. Commonly used hearing tests are:
- Auditory Brainstem Response (example, ALGO) - Three electrodes are placed on the baby's head and a click sound is delivered to the baby's ear by a small headphone. The baby's brainwave response to the sound is recorded and compared to a normal baby pattern.
- Otoacustic Emissions - A small rubber probe is placed in the ear canal. It delivers a sound which travels to the inner ear. The inner ear sends back an echo which is picked up by a microphone in the probe.
- The Crib-o-gram - A loud sound is presented to the infant during light sleep. If the baby responds by arousing from sleep or startling, s/he passes. This test only detects severe hearing loss.
If my baby does not pass the screening test, is s/he deaf?Hearing tests are designed to not miss a possible hearing problem. There are many "false positives" or abnormal tests in babies who eventually turn out to have normal hearing. Things that cause false positive tests include:
- Ear wax or other substance blocking the canal
- Narrow ear canal
- Testing in a noisy setting
- Ear infection
- Restless, fussy baby
- Certain medications
Any abnormal screening test must be verified by another test at later point in time.
After discharge how will I know if my child has a hearing problem?The following is a check list for hearing. All ages listed are based on the child's age from his/her due date, not the date of birth.
- Does your baby awaken, startle or cry to a loud sound?
- Does your baby seem to listen to speech part of the time?
- Does your baby seem to recognize mother's voice?
- Does your baby appear to listen to sounds or speech?
- Does your baby smile when spoken to?
- Does your baby turn toward the person speaking?
- Does your baby distinguish friendly sounds from angry or warning sounds, such as NO!?
- Does your baby notice and look around for the source of new sound?
- Does your baby turn toward the side a sound is coming from?
- Does your baby enjoy vocal play?
- Does your baby coo in more than one tone?
- Does your child turn or look when you call?
- Does your child look for the source of a new sound?
- Does your child listen to sounds or people talking?
- Has your child begun to respond to requests, such as Where is.....?
- Does your child babble?
- Does your child have 3 words?
- Does your child understand and respond to requests?
- Does your child have at least 8 words?
- Does your child have a way of indicating no, either verbal or gesture?
- Does your child respond to rhythm music?
- The child's speech sounds like s/he has a cold even when s/he does not
- The child's speech is difficult to understand
- The child has fewer words than other children his/her age
- The child does not pay attention when someone is speaking
- The child cannot follow simple directions