New research has argued that dyslexia may result from impairment of a different linguistic system than previously thought. Speech perception engages at least two linguistic systems: the phonetic system, which extracts discrete sound units from acoustic input, and the phonological system, which combines these units to form individual words.

Previously, researchers generally believed that dyslexia was caused by phonological impairment, but results from the current study, led by Iris Berent of Northeastern University in Boston, suggest that the phonetic system may actually be the cause.