The din of television noise that serves as the background for many American households may harm early language development for children, researchers say.

In observing interactions between parents and toddlers, a team of social scientists from Hollins University in Roanoke, Va., found that background television noise affected how adults spoke to their children. They watched 49 parents for an hour in laboratory conditions, interacting with their toddlers, aged 12, 24, and 36 months old. With a television playing in the background, the number of words and phrases spoken by the parents dropped precipitously.

For whatever reason, however, the length of phrases spoken by parents was not affected, the researchers said in a news release. The findings should concern parents and pediatricians given that children younger than 2 are exposed to an average of 5.5 hours of television noise per day, they said.

"Our new results, along with past research finding negative effects of background TV on young children's play and parent-child interaction, provide evidence that adult-directed TV content should be avoided for infants and toddlers whenever possible," study author Tiffany Pempek said. "Although it is impractical and probably not desirable for parents to play with their young child all of the time, children do benefit greatly from active involvement by parents during play. Ideally, parents should play with their child without the distraction of TV in the background.

Last year, the American Academy of Pediatrics said children younger than 24 months should not watch television or use similar electronics, such as tablet computers. “A healthy approach to children’s media use should both minimize potential health risks and foster appropriate and positive media use — in other words, it should promote a healthy ‘media diet’,” Marjorie Hogan, an Academy policymaker said in a news release.

Although mobile technology continues to penetrate the eight-and-under demographic, most young children subsist on a media diet heavy on television, with educational content thrown into a Kardashian medley of reality and soaps, sports, and — for some families — 24/7 news channels. Of educational content consumed by children, 61 percent catch programming from television, particularly those of lower socioeconomic backgrounds. Another 38 percent just as frequently consume educational content via mobile platforms, including cellphones and iPads, with 34 percent using computers, according to a new study from Common Sense Media, a non-profit based in San Francisco.

On average, time spent by young children on “traditional” digital media, televisions and DVDs, has fallen by a half-hour per day as overall media use rises, according to the large national survey conducted by the group. As more adults acquire smartphones, including parents newly arrived in immigrant neighborhoods throughout New York City, 72 percent of American children have used mobile technology, ranging from educational games to the ubiquitous Angry Birds.

Amanda Fisher Potter, of Portland, Ore., told Medical Daily she allows Netflix for her children but sets different rules for her nine-year-old daughter Joslyn and 16-month-old son, Zeke. “My daughter plays on my computer probably twice a week for a half-hour and with my cellphone once a week for an hour, but TV is the big one—probably two hours of day,” the 32-year-old court reporter says.

Source: Pempek, Tiffany, et al. Journal of Children and Media. 2014.