Dyslexia and hearing loss

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© Christian Schwier/Fotolia

Researchers at Northwestern University may have discovered a link between dyslexia and hearing.

The Chicago researchers recorded the brainwaves of 100 children with normal hearing, aged six to 13. Using scalp electrodes, they measured the children’s neural responses as they listened to the syllables “ba” and “ga”.

The brainwaves of dyslexic children showed erratic patterns, indicating the children had difficulty encoding the sounds, according to the study’s co-author, Nina Kraus, a professor of neurobiology, physiology and communication.

This deficit in the brain’s ability to recall speech sounds “may be a biological marker of dyslexia,” she said.

Although many different factors may contribute to dyslexia, the link between a child’s reading ability and auditory processing skills appears to be a “highly significant relationship,” said Kraus.

Reading involves an internal hearing of printed language, Kraus explained. As children learn to read, they begin to hear the sounds of consonants, vowels and syllables in their heads and make meaningful connections between sounds and information.

One in 10 people has dyslexia. The reading disability does not affect intelligence, but it does interfere with the ability to recognize words, understand the meaning of a sentence and make sense of written language. The research was published in the Journal of Neuroscience in February.

Source: The Globe and Mail

Rose Simpson