Parallel Language Development in Deaf and Hearing Children
Parallel Language Development in Deaf and Hearing Children
Much of the past research on language development has focused on auditory language learned by hearing children. Recently, researchers such as Jamieson (1995) and Masataka (1992) have begun to study whether language acquisition proceeds in the same manner for deaf children as for hearing children. Results from studies of hearing children learning different languages have shown that the first stage in the acquisition of language is babbling, which usually appears between 7 and 10 months (Lane, Hoffmeister, & Bahan, 1996). Next, between the ages of 12 and 18 months, children make one-word utterances, and by 22 months, most children are at the two-word utterance stage. Children begin to modify words and learn rules for sentence construction by 36 months (Lame at al., 1996).
Parents play an important role in the language development of their children. One unique manner in which parents, and many other adults, talk to children is called "motherese." Motherese is characterized by short sentences, changes in voice fluctuation, slow tempo, and repetition of words. The properties of motherese are thought to enhance early language acquisition by eliciting the infant's attention and demonstrating important aspects of the language (Masataka, 1992). Also, the richness of the language environment the child is exposed to, usually measured by the frequency and type of word the child hears, is positively correlated with the development of language (Levine, 1981).
Children also take active control of language learning. Through babbling, by which an infant repeats consonant and vowel combinations, the child gains experience in language. Once the child reaches the level of speaking word sequences in the native language, ha or she begins to acquire grammatical rules for sentences (Bark, 1997). Although children in this stage frequently make grammatical mistakes, these mistakes are evidence that children are learning and thinking about grammatical rules (Croweon, 1994). private speech, or speech that is spoken aloud but not meant for the benefit of others, is another milestone in the language development of children. Private speech is a factor in cognitive development that helps link thought and language (Jamieson, 1995).
Language Development in Deaf Children
So far, language acquisition has only been discussed in terms of children who learn language by hearing those around them speak. However, there is a substantial subset of children who cannot do this because they are deaf. Most of the research in the past dealing with language development has...