Individuals with extensive hearing loss (HL) who do not use hearing for the ordinary purposes of life are considered Deaf.
Generally, those who consider themselves ‘Deaf’ have hearing loss that is essentially severe-profound where the person has no or very limited functional hearing. Use of hearing is minimized often only to environmental awareness/functional signal warning. Deaf persons have increased dependence on vision.
Deaf persons may be a part of three groups:
1) Prelinguallv Deaf is persons born deaf or acquired deafness in their first five years of life. Speech and language abilities are affected, and may be mechanical and difficult to understand since they are acquired formally and not naturally. Speech and Language development are dependent on amplification and early intervention. Speech and speech (lip) reading ability might be sufficient for basic social expression, but communication is mainly via signs, fingerspelling, and writing. Considerable special education needs required.
2) Postlinguallv Deaf is persons who have acquired deafness after age five during school years. Due to the later onset of deafness, speech and language patterns are fairly well developed. However, continued speech and language development are dependent on amplification and early intervention. Use of language may be affected. Nonetheless, although speech generally is affected, communication is mainly via speech, signs, fingerspelling and writing. Some special education needs may be required.
3) Deafened persons are those who have adventitious (acquired) HL after their education is completed. Speech and language is often nearly normal, however use of speech may be affected, and speech (lip) reading might be needed. Adjustments difficulties might arise due to the late onset of the hearing loss.