A: The American Academy of Pediatrics recommends that children under the age of two should not watch any television. While many parents have some idea that television viewing is not good, most parents are not aware of the negative effects television can have on young children, especially when heard as background noise.
You are right that your infant needs to be exposed to a lot of language, but that language needs to come from human beings in person, not the television. Having the television on in the background has actually been shown to reduce language learning. Because infants have a difficult time differentiating between sounds, TV background noise is particularly detrimental to language development.
In a study focused on word recognition in the presence of background speech, it was discovered that a 7-month-old infant was not able to distinguish words he was familiar with against the background noise. In this study, a woman spoke familiar words at the same time that a monotone male voice spoke in the background. Unless the female voice was at least 10 decibels higher than the male voice, the child did not understand the woman's words. When experimenters attempted to teach toddlers new words in the presence of white noise, the children could not differentiate between “b” and “ch” sounds at the end of a word, learn new words, and retain new words they had been taught. Researchers concluded that the background noise prevented the children from hearing different sounds in the words and prevented them from paying attention and retaining what they learned.
The sheer number of words spoken to a child is directly proportionate to the size of her vocabulary. However, this applies only to direct conversations you have with your child. The words she overhears from television, videos, radio, or other conversations do not count. Two easy ways to expose your child to both quantity and quality vocabulary is by narrating out loud what you are doing through your day and by setting aside time to read out loud. Reading, in particular, exposes children to what researchers call rare words, which are particularly helpful in developing a great vocabulary.