The hypothesis of central auditory processing disorders has been advanced to explain the anomalies of the grapheme/phoneme combination in some dyslexia. These phonological disorders may be linked to abnormalities of the efferent (medial olivocochlear) system modulation and of cortical asymmetry. Indeed, the efferent system has an asymmetry in relation to handedness. Thus, in right-handed subject, it is predominant on the right side. In contrast, in the subject-handed dyslexic, the efferent system tends to be right-lateralized or non-lateralized. However, after an audio-visual training, normal lateralization can appear. This maturation of the efferent system lateralization during reading acquisition seems to have a particular profile in dyslexics with phonological disorder, especially if it is persistent. This finding allows to consider new prognostic evaluation and speech therapy rehabilitation in the dyslexic child.