By Clare Murphy
BBC News health reporter
Does CBeebies have a lot to answer for?
New research suggests having the TV on may impair young children's development by reducing the amount of conversation between infant and adult. So how bad is the box for young minds?
A US team recorded more than 300 children aged between two months and four years on several days every month over two years.
They found that when the TV was audible - either on in the background or being watched - the number of words spoken and sounds made by either adult or child reduced considerably.
It is the latest study to imply that delays in language development may be the fault of TV, a medium blamed for a host of other modern ills, from bullying to obesity.
But while it is not without its problems, experts warn that to expunge it from our children's lives completely may be as undesirable as it is unrealistic.
Certainly there is a body of research building up that finds a correlation between heavy TV viewing at an early age and linguistic problems.
The exact nature of the relationship is unclear, and the role that family circumstances and other social influences play has not been established. However lack of interaction at a personal level is thought to be a key culprit.
But there is equally evidence that, for those over two at least, monitored levels of age-appropriate programmes can in fact foster language skills and indeed improve attention.
Watching with an adult and discussing the contents after a shared experience has been found to be particularly beneficial, but not always necessary providing children are watching high-quality, tailored programmes which contain familiar words and scenarios.
Indeed some psychologists argue that, given young children cannot read their own books or surf the internet, watching may be an empowering experience that gives them access to other worlds which present useful information in a way their parents may not be able to.
But there are some serious caveats: what appears to be particularly undesirable is the viewing of general audience or adult programmes both alone or in the company of a carer.
National Literacy Trust's TV tips
Limit TV time to one hour for 3-5 year olds
Where possible, watch together
Switch off when finished
Encourage imaginative play based on what was watched
Videos/dvds may be better due to repetition of words
Avoid TV in the bedroom
In addition while some TV may be beneficial for the over twos, the evidence for those younger is more shaky. First words, it is argued, are learnt far more effectively from real people than voices on the TV.
In the US, the American Academy of Paediatrics recommends no exposure to TV and computer screens for those under two, but lack of evidence for such a measure means there is no such policy in the UK.
This latest study into TV's effect on children comes from the University of Washington's Dimitri Christakis, the researcher who made headlines after reporting that infants who watched the Baby Einstein series - a set of programmes billed as educational - learnt fewer new words than those who did not.
His new study did not differentiate between TV being watched or background TV, nor did it examine the kind of programmes that were on. But it did find that overall, adults barely spoke to children when the TV was audible.
Research published last year also in the US also found problems with background TV, concluding that it affected both the quality and quantity of play in young children.
Liz Attenborough, director of Talk to Your Baby at the UK's National Literacy Trust, agrees that the permanent presence of the TV in the background is something parents should try to reduce.
"Even if you think you're not paying attention to it, you probably are - and this may well interfere with how much you speak to your child. The TV shouldn't be on all the time.
"But we are lucky to have some high-quality children's programmes in the UK. They are usually well thought-out, often featuring a clear, single voice, and incite children to make responses," she said.
"Of course we need to be aware of the problems TV can pose, but equally we don't want to throw the baby out with the bathwater."