RESEARCH INTO THE ACQUISITION of sign language has usually considered generationally deaf individuals who grow up in a family in which the biological parents sign (Hoffmeister and Wilbur 1980; Morgan and WoIl 2002). The acquisition of sign language by deaf children of hearing parents has received limited research in the past twenty years (Geers and Schick 1988; Hoffmeister and Schick 2000; Livingston 1981). Researchers point out that, for hearing parents, learning to sign is more difficult than it is for deaf parents; moreover, for hearing parents, the mean length of utterance in communication with their child is usually shorter than for deaf parents. A major contributor to the research into sign language acquisition by people with hearing impairment is Mayberry (1993, 1994). Mayberry s study found that many deaf signers acquire sign language in school dormitories and on playgrounds and are therefore older at the time (1994). As one would expect, her study highlighted the fact that the shorter the time deaf individuals have been exposed to sign language, the likelier they are to make errors.
Consistent with what has been observed in those Australian schools that do not use the sign language ot the Deaf community, Mayberry (1994) reported that some form of pidgin Signed English was widely used in educational settings for deaf children. This has considerable implications for those deaf children of hearing parents who learn to sign. Schick and Hoffmeister (2006) found that parents' perceptions of their own ability to understand their child are significantly related to all measures of American Sign Language (ASL) skills. This suggests that their children, if they sign in adult life, will probably learn to sign outside of the home, have limited communication with their parents and siblings, and probably use signs acquired from individuals they associated with at school.
Researchers have relied on self-reporting of ability where formal assessment may not be practical, and this has been used for numerous studies with a reasonable degree of reliability (Gay and Airasian 2000). In studies involving deaf people, Mayberry (1994) and Schick and Hoffmeister (2006) have used s elf-reporting and found it to be reliable.
Signing sets deaf people apart from the hearing community (e.g., Johnson and Erting 1989), but the literature is scant about how the vast majority of deaf people who are not from deaf families learn to sign, the breadth and depth of their working lexicon, and the grammatical structure of their signing.
Nash (1987) stated that in the 19605 most deaf children in the United States enrolled in residential schools, but by the 19805 the number of children in residential settings had decreased significantly (ibid.). Schools for deaf children played an important role in socialization and transfer of sign language, and this has probably had a positive impact on sign language use. According to Emmorey (2002), exposure to sign language would typically have occurred when the children were four to six years of age, when they entered residential schools, but with the transition toward day schooling beginning in the 1960$, exposure to signing occurred much later.
Australian Sign Language (Auslan) has its origins in Britain, with migrants bringing British Sign Language (BSL) to Australia (Johnston 1989), and was influenced by the educational systems of nineteenthcentury Britain (WoIl, Sutton-Spence, and Elton 2001). In addition, WoIl et al. (îbid.) cite the role that French Sign Language has played in Europe and North America. In Australia, Auslan was not officially recognized as a language until the mid-1980s (Lo Bianco 1987), yet several researchers have researched Auslan extensively (Johnston 1989, 1996, 2000, 2003; Schembri 1996, 2003).
Hyde and Power (1991) estimated that approximately fifteen thousand deaf people in Australia use Auslan. In addition, the Royal Institute for Deaf and Blind Children (2004) has cited nearly fourteen thousand deaf people in Australia who use Auslan. …