Auditory phonemic perception in dyslexia: categorical identification and discrimination of stop consonants.

The possibility that phonological confusions may underlie some difficulties in processing written language was investigated using four speech perception tasks. Twelve dyslexic and four normal-reading children identified and discriminated synthetic speech syllables which varied either in voice-onset time (signaling the feature of voicing) or direction of formant transitions (signaling place of articulation). Results indicate that, like normal-reading children and adults, dyslexic children perceive these sounds categorically. Discrimination of the stimuli was limited by their identifiability. It is suggested that linguistic disturbances at other stages of the grapheme to meaning transformation underlie misreading.