COLUMBUS, Ohio -- Eight year-old Britan and her 10-year-old brother, Carson, have been going to the same summer camp for the past two years. For an entire day, they laugh, play games, eat pizza - and then chat with scientists who literally hang on every word they say.
That’s because Britan, who can hear normally, and Carson, who hears through cochlear implants – artificial ears for deaf people - are part of a study in the speech development laboratory at The Ohio State University Wexner Medical Center looking at the relationship between hearing and language skills.
Even though cochlear implants have significantly improved the communication abilities of children with hearing loss, many of these children still lag behind their peers in language and literacy development. For nearly ten years, researchers at Ohio State have been following more than 100 children with normal hearing or hearing loss, some since birth, in order to help find answers that may lead to better implant designs and educational interventions.
Now, researchers say that a surprising picture is beginning to emerge from their studies that could change the way learning problems like dyslexia are detected and treated.
“We’re beginning to see similarities between the language problems of some children with cochlear implants and the language problems of some children with normal hearing who encounter barriers to language learning,” explained Susan Nittrouer, director of Ohio State’s Speech Development Lab. “That’s enormously useful information because we know that the actual signal that children with cochlear implants get isn’t nearly as clear as the signal that normal hearing listeners get. So if language and literacy problems in children with normal hearing are similar to those of deaf children with cochlear implants, maybe the difficulty rests with how they are processing the signal perceptually, even though they have normal sensitivity to sound. That would make sense since language was built on our perceptual capacities.”
With language development, timing is crucial. Most children with dyslexia, a language processing disorder that impacts somewhere between 5 to 20 percent of U.S. children, aren’t usually diagnosed until the third grade. By then, an important window of intervention opportunity has passed. Ohio State has conducted multiple studies to pinpoint this critical window. Nittrouer’s team has been able to identify some accurate predictors of future language and literacy problems in children with hearing loss by the age of three.
“For example, a deficit in the early comprehension of spoken language is a strong predictor of later reading and writing problems,” said Nittrouer. “Perhaps we’ll find that the measures of early language skill that we use with toddlers and preschoolers with hearing loss may actually identify children whose learning problems simply haven’t emerged yet. It would be ideal if we could step in earlier, and change the downstream impact.”
In an upcoming publication, Perspectives on Language Learning and Education, by the American Speech, Learning and Hearing Association, an article by Nittrouer suggests that some current theories of language development might need to be reconsidered, noting that the similarity of literacy problems in children with hearing loss and those with language deficits mandates taking a closer look at the role of perception in language development and new intervention approaches.
Traditional theories suggest that the brain finds acoustic cues within spoken words and automatically translates them into tiny units of sound called phonemes. The phonemes are then used in language production and perception. Consequently, interventions for language and literacy problems focus largely on improving the ability to pick up those acoustic cues in order to correctly recognize phonemes.
Nittrouer and other scientists believe that the translation of sound into phonemes isn’t necessarily automatic, and isn’t the only thing influencing the process. Nittrouer thinks that normal hearing children with dyslexia - unlike children with implants - can probably pick up the necessary acoustic cues, but a problem occurs in how those cues get organized and utilized to in order to correctly perceive language. If that is so, then intervention methods would need to be adjusted.
“If children with implants and normal hearing children with learning problems actually have broader perceptual deficits, we have to broaden our approach.” said Nittrouer. “This means working on more than just letter sounds; it means incorporating activities that engage language perception and organization. This means more than just 20 minutes of tutoring a few times a week is needed. What's needed is a program that involves all educators for the child’s entire day at school.”
Nittrouer believes the hard work of children like Britan and Carson and the dedication of their families will help shape those programs. Research from the camp has already yielded valuable information on language development. For parents of young children just learning to talk, Nittrouer advises the following to help strengthen language skills – or to pick up possible problems
· Context is key. Parents who talk to their children in complete sentences help to facilitate language development for their children. What we don’t want is to just have the child repeat individual words. The “say this” approach doesn’t work very well
· Language and hearing are mechanical and physical processes. Children need to learn that when they move their mouths, different sounds come out. When children produce language they are learning to understand language, and discovering the building blocks of that language.
· Early detection leads to early intervention. Some of the things that you really want to be looking for: How do they do in noisy situations? How are they in terms of understanding what you’re telling them? Are they able to sound out words?
· Look for clues in behavior. A child who appears angry or frustrated may be having problems with comprehension but not be able to articulate why.
The speech development lab and camp are funded by two grants from the National Institute on Deafness and Other Communication Disorders, and have been the source of multiple published studies investigating the reasons children encounter difficulties learning language.
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Contact: Anne Unger, Public Affairs and Media Relations, The Ohio State University Wexler Medical Center, 614-293-3737