Researchers in Sydney have found that Australian babies sometimes struggle with a broad local accent and find it easier to comprehend someone from Canada.

Until now it had been widely thought that infants were more able to distinguish new words if they were delivered in their native language.

But researchers from the University of Western Sydney (UWS) discovered that for some vowel sounds, Australian babies might not have a home-ground advantage.

Associate Professor Paola Escudero looked at why Australian babies did not distinguish certain vowel sounds in their native accent.

"Many studies have shown that there is a bias towards native language, so children like their native language more, they prefer it," she said.

"We thought well if that's the case, then Australian babies should be able to learn words from Australian English much faster, much more easily without trouble."

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Listen Duration: 3 minutes 8 seconds 3 m 8 s Babies baffled by Australian vowel sounds ( Bridget Brennan ) Download 5.8 MB

The researchers tested a new word on dozens of 15-month-old Australian babies.

"What we did is we tried to see whether children had more difficulties if they heard words spoken in one accent as opposed to another accent in English, because there's a lot of variability in the way we pronounce words," Associate Professor Escudero said.

They taught the babies to recognise a made-up word "deet" by playing them recordings of the sound and showing them picture cards to associate meaning with the word.

The researchers then tested if the babies noticed the word had been changed to "dit" or "doot".

When the babies listened to the Australian speaker, they did not notice the vowel changes. They made better sense of the different words listening to a Canadian.

"The reason why the Australian infants performed worse in the Australian accent is because those vowels are a lot more close together; they're a lot more similar in Australian English than they are in Canadian English," said researcher Dr Karen Mulak from the MARCS Institute at UWS.

Vowel sounds make all the difference

Dr Mulak said, at 15 months, babies' brains made sense of sounds and picked up new words and that different vowel sounds could be challenging.

"It depends on how far apart and how distinct the vowels are overall, not necessarily what vowels they're used to every day in their language," she said.

The researchers said the study shed light on why non-English-speaking migrants could find the Australian accent difficult to master.

Associate Professor Escudero said Australian pronunciation of words like sheep, ship or shoot could be misunderstood because of the vowel sounds.

"So it's really interesting how we think of English as one big language, but in fact each individual accent poses different challenges for different listeners and poses sometimes a challenge for infants learning their first language," she said.

The researchers would now test whether other infants at an older age were better able to understand the changing vowels.

They would also research whether Canadian babies could easily understand the Australian accent.