Children acquire language without instruction as long as they are regularly and meaningfully engaged with an accessible human language. Today, 80% of children born deaf in the developed world are implanted with cochlear devices that allow some of them access to sound in their early years, which helps them to develop speech.
However, through early childhood, brain plasticity changes and children who have not acquired a first language in the early years might never be completely fluent in any language. If they miss this critical period for exposure to a natural language, their subsequent development of the cognitive activities that rely on a solid first language might be underdeveloped, such as literacy, memory organization, and number manipulation.
An alternative to speech-exclusive approaches to language acquisition exists in the use of sign languages such as American Sign Language (ASL), where acquiring a sign language is subject to the same time constraints of spoken language development. Unfortunately, so far, these alternatives are caught up in an "either-or" dilemma, leading to a highly polarized conflict about which system families should choose for their children, with little tolerance for alternatives by either side of the debate and widespread misinformation about the evidence and implications for or against either approach.
The success rate with cochlear implants is highly variable. This issue is still debated, and as far as we know, there are no reliable predictors for success with implants.
Yet families are often advised not to expose their child to sign language. Here absolute positions based on ideology create pressures for parents that might jeopardize the real developmental needs of deaf children.
What we do know is that cochlear implants do not offer accessible language to many deaf children. By the time it is clear that the deaf child is not acquiring spoken language with cochlear devices, it might already be past the critical period, and the child runs the risk of becoming linguistically deprived.
Linguistic deprivation constitutes multiple personal harms as well as harms to society (in terms of costs to our medical systems and in loss of potential productive societal participation).
Copyright by the authors: Tom Humphries, Poorna Kushalnagar, Gaurav Mathur, Donna Jo Napoli, Carol Padden, Christian Rathmann, Scott R Smith.Credits/Source: Harm Reduction Journal 2012, 9:16. Published: 2 April 2012. http://www.harmreductionjournal.com/content/9/1/16/abstract
Related posts: Language development milestones in sign language.
This documentation project follows a baby's language acquisition, literacy development, and phonological acquisition in sign language, specifically ASL, week by week from gazing at birth to manual babbling, to first words just before the first birthday in a natural native-ASL environment and visual culture.
The second-year and third-year documentation continues to follow the same child's language and phonological acquisition and literacy development in ASL on a weekly basis from the one-word stage to two-word and multiple utterances.
The documentary continues to follow the same child's ASL language and literacy development on a regular basis from age three to four. It surveys ASL phonological acquisition and more complex utterances.
These posts on ASL-English bilingualism, language acquisition, and bilingual education may be of an interest for parents who raise a bilingual-bimodal child in ASL (or another signed language) and English (or another written and/or spoken language of its respective) as well as informative and educational for ASL specialists, educators, and professionals.