Functional Near Infra-Red Spectroscopic Study of Central Auditory System Cortical Functional Reorganization

Inclusion Criteria : For both groups: * 5 to 16 year-old children, * Absence of pregnancy * Affiliation to Social Security, and children and their parents signed consents will be necessary. * Participation agreement of the protocol and signature of the consent form by the person having parental authority and the child For Single-sided Deafness subjects: \- shall present with moderate to profound unilateral hearing loss, with a hearing loss of 40 decibel(minimal thresholds), assessed on tonal, vocal audiometry, Auditory Brainstem Responses, For Normal hearing subjects: \- shall have normal hearing, demonstrated by air thresholds below 20 decibel by an audiometric control before inclusion , matched in gender and age to children in the experimental group Exclusion Criteria: For both groups: * Antecedents of Psycho-neurological diseases, * Other sensorineural or motor deficiency, * Familial bilingualism, * Medications affecting vigilance. * pregnancy or breastfeeding