Abstract: Individuals with pre-lingual deafness seem to have no phonological awareness, they have a slower development of skills for written words identification than a hearing person and they recognize written words mainly by means of visual strategies. The development of these individuals’ cortical structure is profoundly affected and their general knowledge is organized in an asymmetric structure, as a result of the lack of phonological experiences. Early SL (Sign Language) education is not only helpful for a deaf to improve his SL phonological awareness and his written words recognition skills but also helpful to enhance his cognition development

Key words: deaf, phonology, morphology, conceptual structure