"Parents should know that there is an urgency to assuring that children who are deaf or hard of hearing have access to language as quickly as possible", Dr. Christine Yoshinaga-Itano
ASL Facilitates English and Spoken Language Skills
All Deaf* children can be bilingual by mastering American Sign Language (ASL) and English (reading and writing). ASL and English competency supports spoken language skills. We know all Deaf* children can acquire language visually,
Studies show that the learning of signed language has a positive effect on young Deaf children's spoken language skills." (Snodden, 2008, p. 587)
Early access to language (spoken or signed) is the best predictor of positive spoken language outcomes. (Yoshinaga-Itano & Sedey)
Spatial attention in infants has been found to play a crucial role in the early development of language, whether spoken or sign, as well as to promote healthy parent-infant attachment. (D. Baldwin, 1995)
Many professionals believe sign language hinders speech development in Deaf children. However, a growing corpus of research on the relationship between sign language and spoken language shows that by "facilitating deaf children's acquisition of a signed language enables their access to full linguistic input, which in turn promotes written and spoken language development" (Snodden, 2008, p. 597).
A psychosocial case study by Preisler, Tvingstedt, and Ahlstrom (2002) on Deaf preschoolers using cochlear implants showed "children who had an insufficient command of sign language or whose sign-language development was discontinued also had very little or no spoken language [and the researchers observed] as their sign language increased, they also developed more spoken language" (p. 411).
A case study by Blamey (2003) on signing Deaf and hard-of-hearing children wearing hearing devices resulted in a link being made between high-level linguistic competence and speech perception ability showing high proficiency level in sign language to be an important predictor of speech development. A similar case study by Yoshinaga-Itano and Sedey (2000) also showed a significant link between linguistic ability and speech intelligibility in Deaf and hard-of-hearing children.