Outcomes of Children with Hearing Loss
Mary Pat Moeller, Ph.D.
Ryan McCreery, Ph.D.
Boys Town National Research Hospital
fter the year 2000, the implementation of universal newborn hearing screening changed the way America identified hearing loss in babies. This breakthrough made it possible to diagnose hearing loss at the earliest stage and begin interventions to improve language outcomes. We knew that early identification and early interventions were key to helping a child optimize speech and language outcomes. What we didn't know was how much of an impact early hearing aid fitting and optimizing that hearing aid to the right settings had on these outcomes.
"We just lack evidence of many of the strategies we use every day to bring about positive outcomes.
"So, it was very important for us to have a large scale study to help us understand, are we making a difference in the lives of those children?
Outcomes of children with hearing loss, co-directed by Moeller, and Dr. Bruce Tomblin, a professor at the University of Iowa, aims at closing this research gap.
"Most of the studies that had been published on children who wear hearing aids, had small populations, maybe 20 to 40 children. "
"We wanted a large group of children and we were successful in recruiting 317 children. The way we went about that was to collaborate with other research sites, and so this work is being done here at Boys Town National Research Hospital, along with the University of Iowa and the University of North Carolina at Chapel Hill."
The study, following children for a five-year period, had two main goals.
"If we identify children early in life and fit them with hearing aids, are we making a positive change in their development? Are we preventing language and speech delay? A second, critically important goal, we were curious about the impact of children's hearing aids themselves on development.
"The boost that children could receive from their hearing aids. Would that make a difference in their language learning and their speech learning?"
In order to know if hearing aids are effective for hard of hearing children, hearing aids must be measured themselves to see if they're providing optimal access to speech.
"We collected data over four years, measuring speech through each of the child's hearing aids in the study, and what we found is that, the majority of the children in the study had reasonable access to speech and language through their hearing aids, but for a very small portion of children in the study, they didn't have consistent access for their degree of hearing loss."
This finding lead researchers to predict that children who had more limited access would experience more limited success in speech and language development.
Another aspect considered was how much children were wearing their hearing aids.
Audiologists often communicate with families that the expectation is to have infants wear hearing aids at all waking hours, which is quite difficult for infants to do.
"The data from our study suggests that it might not be a very realistic expectation, especially for infants, but the good news from the data, is that it appears that hearing aid use gets easier and easier as children get older."
"That can be a very positive message for parents, who have a new baby with hearing loss and are experiencing hearing aids for the first time, that there will be challenges but this gets easier as the children get older and that hearing aid use is something we think supports positive developmental outcomes and now we have the evidence to tell parents that."
Researchers also looked at the language environment around these children.
"When parents are talking to three year olds, who have normal hearing, versus three year olds, who are wearing hearing aids, does that talk look the same? The answer was, not always. So, that gives us an opportunity to help support families to create an even richer language environment than they might have because it makes up for the times when it's harder for the child to access the input around them."
The research showed three factors were associated with better speech and language outcomes. These children need a well-fit hearing aid, the hearing aid needs to be worn, and the child needs a rich language environment.
The findings provide specific actions that can be taken in the clinic to address these needs.
"We can fit a hearing aid better, by using best practices; we can use counseling methods, education, and parent to parent contact to help families know how to overcome barriers to hearing aid use with a young child. "
"We can certainly coach families and work closely with them to know the strategies of talking to your child all day about very ordinary things, like changing a diaper or feeding, maximizing those daily interactions to give the child lots of benefits."
A second five-year cycle of the study is underway with researchers following these children as they age up into their school years.
"Instead of listening to Mom and Dad at home, children are in classroom environments where the acoustics and noise level are much poorer but at the same time, children have to learn in these environments and listen."
We want to understand, what are the factors that we identified in early childhood that will promote success in educational and social environments for children as they enter the school age years?"
"Language sets a foundation for reading and writing. It's a very important aspect of literacy. And if your language is weak as a preschooler, we had some concern that it might snowball or have cascading effects on children's literacy development.
How are these children faring? Are they transitioning from language and speech as preschoolers to language as a literacy activity in school, meaning reading and writing."
Questions that will be answered over the next five years providing insights on improving hearing aids and outcomes.
"Our research is important because it gives us the evidence to support what we need to do with these tiny ears so the children are successful in the long run."
In 2008, Boys Town Hospital researchers in audiology and child language development began working with researchers at The University of Iowa and the University of North Carolina at Chapel Hill. The team designed and facilitated a multi-site longitudinal study to examine the outcomes of children, ages 0-6, with hearing aids and the factors that affect these outcomes.
In 2015, the results for this study, Outcomes of Children with Hearing Loss (OCHL), was released, and the research began receiving international attention. The co-principal investigators are Mary Pat Moeller, Ph.D. of Boys Town Hospital and J. Bruce Tomblin, Ph.D., emeritus professor at the University of Iowa.