This article explores the available research literature on language development and language interventions among deaf and hard of hearing (d/hh) children. This literature is divided into two broad categories: Research on natural languages (specifically American Sign Language and spoken English) and research on communication systems (specifically…

Deaf children unable to acquire oral language naturally and who are not exposed to a standard manual language can spontaneously develop a structured sign system that has many of the properties of natural spoken language. This communication system appears to be largely the invention of the child himself. (Authors/BT)