Listening devices are being planted into hundreds of Australian homes as part of research into how children learn to talk. Those behind the study say it may help understand educational development in later life. It’s pretend tea time at the Dorian family home in Adelaide and the kids are busy chatting away. Mother Tina says these siblings have very different approaches to talking. Isaac was slow to develop language his skills because often his older brother Lachlan spoke on his behalf. Isaac, who’s almost four-years-old, was one of the first children bugged with an audio device as part of a major language study. It gave Tina some new insights into his learning.