Professor helps to provide early detection of infant hearing loss

April 6, 2011

Jennifer Simpson, clinical associate professor in speech, language, and hearing sciences, in Purdue's M.D. Steer Audiology Clinic. (Purdue University photo/Mark Simons)

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You may have seen it dramatized in a movie with a yesteryear setting. A parent becomes aware of a child's hearing loss when a toddler appears oblivious to the sounds of banging pots and pans in a kitchen. Today, however, Jennifer Simpson, clinical associate professor in speech, language, and hearing sciences, can make that diagnosis in infants as young as 3 or 4 weeks old. She's part of a trio of such licensed professionals at Purdue who also trains graduate students to work in the field.

Simpson -- alongside colleagues Lata Krishnan, clinical associate professor, and Shannon Van Hyfte, clinical assistant professor -- provides services for infants and families in Tippecanoe and surrounding Indiana counties. The professors are certified by First Steps, the State of Indiana's early intervention system for infants and toddlers with special needs.

Shortly after birth, babies are given a pass/fail hearing test. Infants who fail are sent to an audiologist like Simpson, who then performs a diagnostic test to determine any levels of hearing loss.

"Most babies pass once they come to us, but there are a handful we identify with some degree of hearing loss," says Simpson, who estimates that of the 100-150 infants they test annually, maybe five to 10 have some permanent loss of hearing.

Often with a grad student on hand for training purposes, Simpson will place electrodes on an infant's forehead and behind his or her ears. As a seated mother holds her sleeping baby, Simpson sends sounds through earphones, changing the intensity and the frequency. She's looking at brainwaves to make her diagnosis.

"You can never predict how people are going to react when they hear the news," Simpson says of the times she has to confirm a hearing loss. "Some people cry and others might be in a bit of shock. You just have to be mindful of the different ways people react. It's a very difficult diagnosis for parents, so counseling becomes very important."

Once a hearing loss is determined, Simpson refers the family to an ear nose and throat physician. With medical clearance, she can make an impression of the infant's ears and send that material to make tiny ear molds.

"A small hearing aid goes behind the ear," Simpson says. "We then need to replace the ear mold every three months because they grow so fast."

In the last few years the push to identify affected children early has led to early intervention with the available technology, Simpson says. A baby with severe to profound hearing loss may be eligible for a cochlear implant. For any child identified with a hearing loss, monitoring tests every three to six months are crucial.
The clinic itself has become a perfect learning laboratory for graduate students. As director of clinical education in audiology, Simpson also teaches classes and serves as the liaison to the Indiana University School of Medicine, where fourth-year students rotate through four Indianapolis hospitals.
"Our big goal is really one, three, and six," Simpson says. "All babies should be screened for hearing loss by one month of age. Those who need it should have a diagnostic test by 3 months of age. And by 6 months, babies with a diagnosed hearing loss should have an appropriate intervention in place."