Deaf Children of Hearing Parents Have Age-Level Vocabulary Growth When Exposed to ASL by Six-Months.

OBJECTIVE: To examine whether deaf or hard of hearing children who have hearing parents can develop age-level vocabulary skills when they have early exposure to a sign language.

STUDY DESIGN: This cross-sectional study of vocabulary size included 78 deaf or hard of hearing children between 8- and 68-months-old who were learning American Sign Language (ASL) and had hearing parents. Children who were exposed to ASL before 6- months-old or between 6- and 36-months-old were compared with a reference sample of 104 deaf and hard of hearing children who have deaf, signing parents.

RESULTS: Deaf and hard of hearing children with hearing parents who were exposed to ASL in the first six months of life had age-expected receptive and expressive vocabulary growth. Children who had a short delay in ASL exposure had relatively smaller expressive but not receptive vocabulary sizes, and made rapid gains.

CONCLUSIONS: Though hearing parents generally learn ASL alongside their deaf children, their children can develop age-expected vocabulary skills when exposed to ASL during infancy. deaf children with hearing parents can predictably and consistently develop age-level vocabularies at rates similar to native signers; early vocabulary skills are robust predictors of development across domains.