Lexical Development of Deaf
Over the past few years, most states in the United States have passed laws requiring newborn hearing screenings. With these screenings, many deaf children are now being identified early, typically before 6 months of age, and receiving necessary language intervention services well before their first birthdays. While many of our previous reports on the lexical acquisition of deaf children have focused on case studies and children older than 3 years, we are now in a unique position to more thoroughly evaluate young deaf children's sign language acquisition. In this chapter, I review our current understanding of the acquisition of the lexicon in American Sign Language (ASL) and manually coded English (MCE). Specifically, the acquisition of first signs, negation, and whquestions are discussed along with vocabulary size and its early development. Where possible, the development of signed languages is considered in light of specific variables such as degree of hearing loss, parental hearing status, and age of initial exposure to a signed language that likely affect sign language acquisition.
Deafness is defined as a hearing loss that is so severe that the person, with or without amplification, is limited in processing linguistic information through hearing. Congenital hearing loss occurs in about 1–3 infants per 1,000 born in the United States. According to the American Speech-Language-Hearing Association (2004), more than 30 children will be born deaf in the United States every day. Of these births, only