Tuesday, April 12, 2011

Mind & Brain - Psychologists Test Effects Of Household Noise On Children's Verbal Development

September 1, 2005 — Psychologists think that children who grow up in noisy homes may have lower verbal skills. New studies aim to test whether the constant background noise of a TV set or of other children playing learn to speak later and with poorer vocabulary.

LAFAYETTE, Ind.--Can the noise level inside your house actually make it harder for your baby to learn to talk? Researchers now say turning down the TV can actually help your child find their voice faster.

From the TV, to noises in the next room, a home can be full of distractions. But how much is too much? That's what psychologist George Hollich, from Purdue University in West Lafayette, Ind., is trying to figure out. He is putting babies to the test to see if all that noise delays their ability to learn to speak.

Hollich says, "It seems to be the case that in noisy households, kids have lower vocabulary skills." As part of the test, the child watches a film of a woman talking, while a distracting man's voice competes for his attention. In the video, the woman keeps repeating the word feet.

"One of the things they can do is use what they see to hear a little bit better," Hollich says. Even with a distracting voice in the background, the child can pick out the right word.

Amanda Seidl, mother of the 10-month-old test child, practices infant-directed speech. Although her son is more interested in destroying the books than reading them, his mom knows how important it is for him to see and hear her speaking. Seidl says, "He's been babbling for a really long time."

To practice infant-directed speech, talk louder, minimize distractions and make sure your child can see your face or your hands when you talk to them. This can result in your child learning to speak sooner and have a larger vocabulary later.

Background noise in the average household, such as other children playing or watching television, can pose the same problem for children that an older adult with hearing loss encounters at a cocktail party.

BACKGROUND: Studies have shown that infants learn language faster when what they see is synchronized to the sound that they hear. The visual clues also help infants cope with learning a language in noisy environments.

HOW WE LEARN LANGUAGE: Babies start to babble in strings of words at around six or seven months, but even before that, infants are busy sorting out the sounds and shapes of words and sentences. Unlike the printed word, speech doesn't use commas, spaces or periods to separate words and concepts. So if there is background noise, it's harder for the infant to known when one word ends and another begins.

THE RESEARCH: Four studies involving 116 infants were conducted at Johns Hopkins University in 2002 analyzed how noise nearby affects 7-month-old infants during this early stage of language development. The babies were shown different videos of a woman talking while emphasizing a specific word, such as "cup." In one version, the audio matched what the woman was saying; in another, it didn't; in a third, the audio was matched with a still frame of the speaker.

THE FINDINGS: The researchers found that even moderate background noise can affect how infants learn language, reaffirming how important it is for a child to see the face of a person while hearing him or her speak. Infants who watched the first version of the video, where they could see the woman's face while she spoke, focused on the emphasized word an average of two seconds longer than on the surrounding words. That's a long time in an infant's limited attention span. Background noise -- such as other children playing or watching TV -- poses the same problem for children that an older adult with hearing loss might encounter at a crowded cocktail party.

PARENT PRIMER: So-called "parentese" -- the undulating baby talk most parents employ when speaking to infants -- is actually one of the best ways to help your baby learn language. It highlights the boundaries between words, phrases and clauses, which helps children learn the structure of the language.

Note: This story and accompanying video were originally produced for the American Institute of Physics series Discoveries and Breakthroughs in Science by Ivanhoe Broadcast News and are protected by copyright law. All rights reserved.

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