At the National Institutes of Health’s Consensus Development Conference on Early Identification of Hearing Loss in 1993, participants concluded that newborns should have their hearing screened before they leave the hospital. Today, more than 95 percent of babies born in the United States have their hearing checked through universal hearing screening programs shortly after they’re born.
That’s a good start, considering early detection and intervention are necessary to help hearing-impaired children learn language skills. Studies indicate that children whose hearing impairment is identified and treated by six months of age have a greater chance of developing language and communication skills equal to their peers by the time they start kindergarten.
Hospitals typically use two standard tests to screen a newborn’s hearing. The Otoacoustic Emissions Test (OAE) uses a tiny earphone and microphone to measure the echoes that are released by the inner ear after it’s been exposed to an external sound. The Auditory Brainstorm Response (ABR) measures the hearing nerve’s response to sound by playing sounds into the baby’s ears and measuring the responses with small electrodes attached to the head. Both tests are comfortable for the newborn and produce reliable results. Hospitals may use one or both of these tests to screen their newborns.
Some babies fail their first screening because amniotic fluid or other debris is still present in the ear. Most of these newborns pass their second screening. Those who don’t are referred to a pediatric audiologist who specializes in testing the hearing of infants and children and is trained to fit hearing aids.
After the pediatric audiologist has collected family health history, they will conduct a series of tests designed to identify which part of the auditory system is affected and how much hearing loss exists. Most likely, the OAE and ABR screenings will be repeated. Additional tests may also include:
- Auditory Steady Rate Responses. This test is a more intensive measurement of the baby’s hearing than the ABR and may give the pediatric audiologist better frequency threshold information for those infants with severe to profound hearing loss.
- Tympanometry uses air pressure to measure the condition of the middle ear and the ear drum (tympanic membrane).
- Behavioral Audiometry screenings test the lowest frequency of sound the baby can hear. Because of the nature of the test, many pediatric audiologists use visual reinforcement audiology (VRA). This may include measuring when the child will turn his head to look at a toy emitting different levels and frequency of sound. For this reason, this screening is most effective for children between the ages of six and 36 months.
Because these tests only identify hearing loss present at the time of screening, parents will want to have their child’s hearing tested at other times during childhood especially if the family health history reveals the child may be at risk for future hearing loss. Pediatricians recommend children with healthy hearing continue to have their hearing evaluated at ages 4, 5, 6, 8, 10, 12, 15 and 18 and any other time there’s reason for concern.