The ability to encode the speech signal is determined by ascending and descending auditory processing. Difficulties in processing these speech signals are well described at the behavioral level in a specific language disorder. However, little is known about the underlying pathophysiological mechanisms. The assumption is that we should observe a degradation of the signal provided by the ear in the deaf subject while in case of specific language impairment it would be a phonemic disorder (possibly linked to a processing disorder auditory). The two population groups should therefore have different abnormalities of their central auditory process - which could be modified by the target remediation for each group.

Inclusion Criteria:

For all subjects:

• native French speaker
• no medical treatment for behavior or neurological disorders
• normal or corrected vision
• right-handed
• normal otorhinolaryngology examination
• valid affiliation to social security
• no participation to another research study

For the normal-hearing subjects

• normal tonal hearing thresholds
• normal tympanometry

For the subjects without specific language impairment

• aged from 6 ro 40
• normal school attendance without scholastic retardation
• normal intellectual level
• normal for age reading skills
• no delayed speech (expression & production)

For the children with specific language impairment

• aged fom 8 to 18
• persistent specific literacy difficulties with reading levels at least 18 months behind that of their peers
• normal intellectual level

For the hearing impaired subjects

• age from 18 to 70
• first auditory rehabilitation
• bilateral and symmetric hearing loss (±10 dB) with hearing thresholds between 0 and 25 dB at 0.25 kilohertz, 0 and 35 dB at 0.5 kilohertz, 0 and 50 dB at 1 kilohertz, 25 and 70 dB at 2 kilohertz, 25 and 80 dB at 3 kilohertz, 30 and 80 dB at 4 kilohertz

Exclusion Criteria:

• non signed assent
• treatment for depression, epilepsy, Parkinson's or alzheimer's disease during more than 6 months
• physical health deficiency
• mental retardation
• neurological or psychiatric disease incompatible with testing procedure

For children

• known problem of hearing loss or chronic middle ear disease whic compromized the hearing status
• schooling in a foreign language
• foreign language spoken at home with both parents