June 29 (HealthDay News) -- If you want to help children develop language and speech skills, UCLA researchers say, listening to what they have to say is just as important as talking to them.
The effect of a conversation between a child and an adult is about six times as great as the effect of adult speech input alone, the researchers found. The results of their study appear in the July issue of Pediatrics.
"Adults speaking to children helps language develop, but what matters much more is the interaction," said the study's lead author, Frederick Zimmerman, an associate professor in the school of public health at the University of California, Los Angeles. "The child speaking is a big part of what drives language development. The more the child speaks, it reinforces their knowledge."
The researchers also found that TV viewing didn't have much of an effect -- positively or negatively -- as long as it wasn't displacing conversations between an adult and a child.
That, however, may be exactly what's happening in many homes. A study in the June issue of Archives of Pediatrics & Adolescent Medicine found that for every additional hour of television exposure, young children heard 770 fewer words from an adult. And, infants watching TV made fewer vocalizations when adults spoke to them.
The UCLA study included 275 families with children between 2 months and 48 months old. They represented a variety of incomes and education. Most families were white, with 3 percent of the families black, 8 percent Hispanic and 7 percent another non-white ethnicity.
On a randomly chosen day, parents recorded their child's entire day, from wake-up until the child went to sleep. Each family provided about five full-day recordings during the six-month study. In addition, 71 of the families continued the study for 18 months longer.
The researchers found that, in an average day, children hear about 13,000 spoken words from adults and participated in about 400 adult-child conversations a day.
Assessed separately, factors positively associated with language development included each additional 100 conversations a day and each 1,000 word increase in the number of words spoken by adults and heard by children. When looked at alone, TV was negatively associated with language development.
But, when the three factors were analyzed together, the only one that stood out was conversation between adults and children.
"The more a child speaks and interacts with an adult, the better idea a parent has about where the child is," Zimmerman said. "Although it's mostly done unconsciously, parents will provide feedback and correct mistakes. They'll also tailor their speech to the child."
"This study supports what we recommend to families," said Maxine Orringer, a speech-language pathologist at Children's Hospital of Pittsburgh. "When there's conversation, you get practice communicating. The child can make a mistake, and that helps parents understand what the child's perception is, and it can help them correct those mistakes," Orringer explained.
"Parents can give a child words by talking to them about what they're doing, such as, 'I'm putting on your pajamas now.' But give your child the opportunity to talk, hopefully without the rest of the noise in the environment," she added. "If parents can carve out some conversation time -- maybe at bath time or at dinnertime -- that's a wonderful thing."
Adults should remember that "sometimes it's quicker and easier just to tell children what to do, and it's difficult to slow down, but that's what's important for language development," Zimmerman added.
"Conversation should always be a two-way street," he said.
SOURCES: Frederick J. Zimmerman, associate professor, School of Public Health, University of California, Los Angeles; Maxine Orringer, M.A., speech-language pathologist, Children's Hospital of Pittsburgh; July 2009, Pediatrics