Background noise from the TV or radio can make it harder for toddlers to learn new words, according to recent research.

Scientists carried out experiments in which two-year-olds were taught new words, while hearing soft or loud background speech.

The toddlers exposed to the quieter sounds were the only ones who learned the words successfully.

They were also better at grasping the meaning of words that had earlier been learned in a calm environment, further tests showed.

A total of 106 children, aged between 22 and 30 months, took part in the study.

They were taught names for unfamiliar objects, and then tested on their ability to recognise them when they were labelled.

The scientists said that the findings may be even more relevant to crowded low-income households that tend to have higher noise levels.

The research is reported in the journal, Child Development.