By Serena Gordon
THURSDAY, Sept. 6 (HealthDay News) -- Devices that amplify the sound of a teacher's voice may help children with dyslexia improve their reading skills, new research suggests.
After a year of wearing the devices in the classroom, children with dyslexia had improved scores on tests of phonological awareness and reading.
"We saw improvements in reading, and when we measured the brain's response to speech sounds, not only did the kids who wore the device become more consistent to the very soft and rapidly changing elements of sound that help distinguish one consonant from another, but their brains responded more consistently to sounds," said study senior author Nina Kraus, a neuroscientist at Northwestern University in Evanston, Ill. "That improved stability was linked with reading improvement."
Results of the study were published in the Sept. 4 issue of the journal Proceedings of the National Academy of Sciences.
When people think of dyslexia, they often think of someone seeing letters backward. More recent research suggests, however, that difficulties in phonological processing are a problem for children with dyslexia.
"Phonological processing relies on so many different pieces of information, like the auditory processing of sound," explained Dena Klein, a psychologist at Montefiore Medical Center in New York City. "If the sound isn't clear, it's hard to make a connection for what those sounds represent, and, in turn, that makes it hard to read."
"For some kids, there's an unstable recognition of sounds that impedes the sound-to-meaning connections that need to be made in order to learn to read," she said. "But if the child is hearing the teacher's voice right in his ear [through an assistive listening device], it makes him pay attention. It enables the child to know what to pay attention to."
In the current study, Kraus and her colleagues studied the impact such listening devices could have on children with dyslexia. Thirty-eight children between the ages of 8 and 14 participated in the study. All were attending a school for children with reading problems. The goal of the school is to get the children's reading levels back on track so that they can return to their usual school.
Nineteen students wore an assistive listening device throughout each school day for the entire school year. The other 19 children were the control group.
The device is simple. The teacher wears a microphone, and each child wears an earpiece, similar to a Bluetooth receiver, that puts the sound of the teacher's voice directly in the child's ear.
"The idea is that if you have the teacher's voice directly piped into your ear, you will focus more on that and be less distracted," Kraus said.
The researchers administered a number of reading tests at the beginning and end of the study. They also conducted tests to measure the brain's response -- through increased electrical activity picked up by electrodes worn outside the brain -- at the beginning and end of the study.
They found that the group that wore the listening devices had improvements in reading that the children in the control group did not. They also noted changes in the way the brain responded to sounds in the children who wore the device that they didn't see in children in the control group.
"Before and after a year of use of the device, the brains of kids who wore the device responded more consistently to the very soft and rapidly changing elements of sound that help distinguish one consonant from another, such as cat, bat and pat. That improved stability was linked with reading improvement," Kraus said. "When you start to hear things, you can make associations between what you hear and what it means. If you improve the auditory processing of sound, you give children a better chance to connect what it all means, and they can then connect that to what they see on paper."
Although children with attention-deficit disorder weren't included in the study, both Kraus and Klein said they thought these types of devices could be useful for those children.
Assistive listening devices are currently available for use in classrooms, and can come in different forms. The simplest, said Kraus, might be a microphone for the teacher and a wall-mounted speaker to increase the teacher's volume for all of the students.