Dyslexia: The Role of Hearing and Auditory Processing

Doctors have known for years that those with dyslexia process information differently than others, like seeing words with transposed letters but there is mounting evidence that they might also hear language differently, as well.

“Any sort of language problem could very well have its roots in perception itself,” said Susan Nittrouer, Ph.D., of The Ohio State University Wexner Medical Center. “To many people, the solution seems to be, well, we will just train those with dyslexia how to recognize words correctly but the problem is really more fundamental than that.”

Nittrouer said she began to suspect the role hearing might play in dyslexia after nearly a decade-long study involving children who were born deaf or with profound hearing loss.

“We began following this group of over a hundred children, basically, since they were infants,” Nittrouer said.

All the children in the study got cochlear implants, which use microphones mounted just behind their ears, to capture and feed sound waves to nerves near the brain.

Through consistent testing, researchers found that the implants made a remarkable difference in terms of childrens’ ability to hear, but they’ve raised some intriguing questions as well.

“Cochlear implants have been able to help children who are deaf basically function as hearing children do,” said Nittrouer.

“However, once you begin to scratch the surface, you often find that children who have cochlear implants function similarly to how children who have dyslexia function.”

Nittrouer says that’s important because it points to the role of hearing in dyslexia. “Given that they look so much like children with dyslexia,” said Nittrouer, “we can really connect the dots between their perception, the kind of signal that they’re getting, and the sort of language problem that results.”

Even more encouraging, is that researchers say they spotted problems in these children long before they would have been obvious in dyslexic children who have normal hearing.

“We were able to identify these emerging problems in these children at kindergarten,” Nittrouer said. “If they didn’t have cochlear implants and weren’t in this project, in all likelihood, these problems learning to read would not have have shown up until they were in 3rd grade.”

Nittrouer says more research need to be done, but her findings could eventually lead to a new approach to dyslexia.

“We might be able to develop tests that could be administered earlier to predict who might be at risk for dyslexia,” she said.

“If, indeed, it turns out to be that these children have broader perceptual issues, then we need to begin to put together a broader intervention approach,” said Nittrouer, “one that does not involve just pulling the children out of the classroom for 20 minutes of tutoring a few times a week, but rather a program that involves all educators for the child’s entire day at school.”

¹What is Dyslexia?, National Center for Learning Disabilities, (citing the National Institute of Child and Human Development), June 2012.