Repeat after me! Boosting toddler vocabulary

Research from the University of Maryland and Harvard University suggests that young infants benefit from hearing words repeated by their parents, and that parents who repeat words more to 7-month-olds find their children have larger vocabularies when they are toddlers. With this knowledge, parents may make conscious communication choices that could pay off in their babies’ toddler years—and beyond. The research was recently published in the Journal of Child Language.

“Parents who repeat words more often to their infants have children with better language skills a year and a half later,” said co-author Rochelle Newman, professor and chair of the University of Maryland Department of Hearing and Speech Sciences (HESP).  “A lot of recent focus has been on simply talking more to your child—but how you talk to your child matters. It isn’t just about the number of words.”
Newman and co-authors HESP Professor Nan Bernstein Ratner and Harvard's Meredith L. Rowe tracked maternal-child directed speech to prelinguistic (7-month-old) infants. They specifically measured the infants’ ability to understand language at 7 months, and later the children’s vocabulary outcomes at age 2. They found that the toddlers who had stronger language outcomes differed in two ways from their peers: their parents had repeated words more often, and they were more tuned in to the language as infants, and thus better able to process what was being said. 
“It takes two to tango,” said Dr. Ratner. “Both the child and the parent play a role in the child’s later language outcomes; our study is the first to show that.”
The researchers believe their findings will be of immediate use to families. While it has been clinically proven that parents naturally speak more slowly and in a specialized “sing-song” tone to their children, the findings from this study will perhaps encourage parents to be more conscious of repeating words to maximize language development benefits.
Still, “it is the quality of the input that matters most, not just the quantity,” said Dr. Rowe.
This new study builds on a growing body of research from HESP focused on exploring infant language development. Professor Newman and two of her then-graduate students recently published “Look at the gato! Code-switching in speech to toddlers” in the Journal of Child Language. That study examined the phenomenon of “code-switching,” wherein adults speak more than one language and “mix” those languages when speaking to their children. A lot of parents are told that this type of language mixing is bad for children, but Professor Newman and her colleagues found that this “code-switching” has no impact on children’s vocabulary development.
Nan Bernstein Ratner 
Department of Hearing and Speech Sciences