Lu said, "Train them in noise."
The new study in Psychological Science builds on similar results published by the team of Sperling, Lu, Manis and Seidenberg last year in Nature Neuroscience.
In addition, the same authors previously showed that poor readers also have trouble figuring out categories in simple card games.
Other recent studies lend support to the noise exclusion theory.
Johannes Ziegler of the Universite de Provence in Marseille, France, was the lead author on a study of dyslexia and auditory noise published this year in Proceedings of the National Academy of Sciences.
Ziegler said his results suggest that dyslexia stems from shaky categories for phonemes (the basic sounds of language).
"In silence, information is often redundant and dyslexics get away with the perception deficit," Ziegler said in an e-mail. "In noise, however, they can no longer compensate.
"What is important is that noisy environments are the rule and not the exception," he added, citing a study from South Bank University in the U.K. that found average noise levels in primary classrooms to be as high as near a busy intersection.
"What Sperling and Lu's data suggest is that the mechanism responsible for faulty phonological development is quite general and has to do with attention in a broad sense....
"This is a great paper of very high significance... As people like Steve Grossberg [of Boston University] have argued for many years, attention ... is crucial for stable learning of categories."
Ziegler called for preventive training for children with weak speech perception in noise in kindergarten or early primary grades, saying they are at greater risk for developing dyslexia.
He also cited a Northwe
Source:University of Southern California