”Only a minority of profoundly deaf children read at age-level. We contend this reflects cognitive and linguistic impediments from lack of exposure to a natural language in early childhood, as well as the inherent difficulty of learning English only through the written modality. Yet some deaf children do acquire English via print. The current paper describes a theoretical model of how children could, in principle, acquire a language via reading and writing. The model describes stages of learning which represent successive, conceptual insights necessary for second/foreign language learning via print. Our model highlights the logical difficulties present when one cannot practice a language outside of reading/ writing, such as the necessity of translating to a first language, the need for explicit instruction, and difficulty that many deaf children experience in understanding figurative language. Our model explains why learning to read is often a protracted process for deaf children and why many fail to make progress after some initial success. Because language acquisition is thought to require social interaction, with meaning cued by extralinguistic context, the ability of some deaf individuals to acquire language through print represents an overlooked human achievement worthy of greater attention by cognitive scientists.”
You can read more in this journal article by Robert J. Hoffmeister and. Catherine L. Caldwell-Harris.