New study looks at outcomes for kids with hearing loss
University of Iowa is helping kids hear better, and giving them a better chance at success in life.
The results of a groundbreaking new study, called “The Outcomes of Children with Hearing Loss” shows the tremendous benefits that kids with hearing impairment receive from early diagnosis and intervention. The findings were published October 27th in the journal Ear and Hearing, published by the American Auditory Society.
According to the NIDCD, about 2 to 3 children out of every 1000 are born with at least some hearing loss in one or both ears. With intervention they can be developmentally on par with their hearing peers, but without intervention the cost is tremendous; Not only does language development lag behind, but they also suffer socially, educationally and emotionally. And there is a financial cost as well; the cost to educate one hearing impaired child through high school is estimated to exceed $400,000 , according to the National Center for Hearing Assessment and Management.
Other studies on children with hearing impairment have been done in the past, giving researchers not only a clear picture of the importance of early diagnosis and intervention, but of the delays in language development that can result. But until this point no research had been done on the outcomes of children with hearing loss, and determining which interventions would actually best help children succeed.
Researchers at the University of Iowa partnered with researchers at the Boys Town National Research Hospital and the University of North Carolina at Chapel Hill, bringing together professionals in the fields of audiology, speech-language, psychology and biostatistics for this important study, the first ever to look at the specific impact of intervention on language development. The study, funded by the National institutes of Health and the NIDCD, focused on specifically on infants and very young children with hearing impairment that ranged from mild to severe.
The first of its kind in the nation, this 4 year study looked at 317 children ages 6 months to 7 years whose hearing impairment ranged from mild to severe, and compared those children to 117 children with normal hearing. The study participants came from 17 different states; the majority had bilateral permanent hearing loss and had already been fitted with hearing aids. The researchers were looking to answer one question in particular: what is the outcome of early diagnosis and intervention on children with hearing impairment?
The results of the large-scale study could have a major impact on children with hearing impairment going forward. The study confirmed not only that children with hearing loss or impairment have poorer language development than their peers with normal hearing, but also that the more severe the hearing impairment, the greater the impact was on language development.
Logically, it would seem that hearing aids alone would be the solution. But in a twist, the study showed there was one caveat: the hearing aids must fit properly to have the greatest impact on language development. During the study it was discovered that 35 percent of the participants’ hearing aids had been improperly fitted, which reduced the amount of speech information they received through the hearing aids. The researchers faced a dilemma, but ultimately chose not to refit the children’s hearing aids.
“That was an ethical dilemma,” said Beth Walker, a researcher and communication-sciences and disorders assistant professor at the University of Iowa, explaining the researchers’ decision not to intervene and refit the hearing aids themselves. Instead, each of the children received a printout to take home with targets as well as proper settings, thus giving the responsibility of properly fitting the hearing aids to the child’s parents.
The study also showed that providing hearing aids in early infancy results in better outcomes, whereas later fittings showed delays in language development. However the good news is that in this case it is“better late than never”, because fitting hearing aids later as opposed to not at all was still beneficial to language development. Also, researchers found that consistent daily use of hearing aids provides more protection against language delay and actually supports auditory development.
This study wouldn’t have been possible a generation ago. The reason? 76 percent of the participants were identified as being hearing impaired through newborn hearing screenings, which didn’t begin to become widespread until the Newborn and Infant Hearing Screening and intervention Act of 1999. Today, 43 states and the District of Columbia mandate hearing screenings for newborns; 97 percent of all infants go through newborn hearing screening, which allows health care providers to identify a possible hearing impairment early on. The earlier a hearing impairment is diagnosed, the more intervention can occur before a child is through with critical phases of his language development.
“Hearing well is crucial to developing linguistic skills, building social connections, and succeeding in life,” says Mary Pat Moeller, director of the Center for Childhood Deafness and the language development laboratory at Boys Town National Research Hospital. “Research now provides strong evidence in support of these expectations.”