Dyslexia: the phonological impairment

Some excerpts: 

Individuals with dyslexia have trouble recognizing (...) phonetic differences, whether a person is speaking a familiar language or a foreign one.

Individuals with dyslexia were significantly worse at being able to consistently recognize the voices of the English speakers.

It is remarkable that individuals with dyslexia are no better able to identify voices speaking a familiar language than a foreign one.

The result reaffirms the theory that the underlying deficit in dyslexia isn't about the act of reading per se, but instead involves difficulty with how sounds of spoken language are heard and processed in the dyslexic brain.

What theories of dyslexia have not been able to convincingly explain, say the researchers, is why there is no evident difficulty in the ability to perceive and produce speech among people with dyslexia. This is especially curious if the ability to recognize phonological sounds is impaired.

The results suggest that the source of a phonological deficit might be in dyslexic individuals' difficulties learning the consistent properties of speech sounds as spoken by an individual talker.

"Lots of research has shown that individuals with dyslexia have more trouble understanding speech when there is noise in the background," says Perrachione. "These results suggest that trouble following a specific voice might be part of the cause. Teachers and other educators can be sensitive to this during classroom instruction where noise from other classmates might make it disproportionately difficult for children with dyslexia to follow what is going on in a lesson."

Here.