By: Amanda Womac
Published Nov. 9, 2010

Every day in the United States, approximately one in 1,000 newborns is born profoundly deaf. That’s about 33 babies each day. Another two to three newborns out of 1,000 are born with partial hearing loss, which makes hearing loss the number one birth defect in the United States.

However, newborn hearing tests are not universally provided in hospitals across the county. In 1998, only 22 percent of newborns were tested at birth for hearing loss. But, the practice is becoming more and more common in hospitals or maternity centers. Currently, around 69 percent of newborns are screened.

If not detected at an early age, hearing loss can have a significant impact on a child’s educational development and quality of life. When hearing loss is detected late, language development is already delayed.

Children whose loss is not detected early are more likely to perform below their grade level. These kids are also more likely to be held back, drop out of school and fail to earn a high school diploma. The consequences are in sharp contrast to those for children who are identified early and receive early intervention. These kids often function at the level of their peers by the time they enter school.

Screening Techniques
Screening in newborns can detect permanent or fluctuating loss; if the loss is bilateral or unilateral; and whether the loss is sensory or conductive.

Before the 1990s, doctors relied on input from the babies to test hearing loss. Technological advances have allowed doctors to conduct tests that measure otoacoustic emissions and auditory brainstem responses. Both of these procedures are noninvasive and can be done with the infant sleeping.

When audible sounds stimulate the cochlea, the outer hair cells of the cochlea vibrate producing an inaudible sound that vibrates back into the middle ear. This is called an otoacoustic emission (OAE) and can be measured with a small probe inserted into the ear canal. If the emission is present, the newborn’s hearing is fine. However, if it is not present, a loss of greater than 25 to 30 dB is likely. OAEs can also detect blockage in the outer ear canal, middle ear fluid, and damage to the outer hair cells in the cochlea.

Another newborn hearing test is called auditory brainstem response. Electrodes are placed on the infant’s head to record the brain wave activity in response to auditory input, or sound. This test can detect damage to the cochlea, auditory nerve or auditory pathways in the brainstem.

Improvement in Infant Hearing Testing
Although hearing tests for newborns are accurate, they do carry some challenges. Infants mush be very quiet and still in order for the tests to be accurate. Electronic and environmental noises also pose additional problems when obtaining accurate measurements.

Because of these issues, Dr. Barbara Cone, pediatric audiology specialists at the University of Arkansas, is investigating ways to improve hearing assessments for newborns.

Cone received a $200,000 grant for the Association of University Centers on Disabilities to lead a team of researchers conducing three separate investigations to determine best approaches for newborn testing. The UA project was named one of the association's 2010 Research Topics of Interest, which comes with funding for a two-year period.

During the grant period, Cone's team will test a new device designed for early hearing loss detection, investigate a process that focuses on brain stem responses and also evaluate a technique that focuses on the auditory cortex in the brain.

Hope and Hearing in Tennessee
Because we recognize the importance of newborn screening, the Hearing and Speech Foundation started our Hope and Hearing Program in April 2010. Through this program, newborns who fail their initial test are eligible for an additional test from HSF at no charge to the parents.

The goal of this project is to identify newborns and children with hearing loss and assist them with the hearing services they need to develop speech. Since its inception, HSF has provided additional testing to over a dozen children in Blount County.

For more information about this program, click here.

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