The research, led by Murdoch Children’s Research Institute (MCRI) and published in the Archives of Disease in Childhood, identifies red flags to help guide speech therapy referrals.

In addition, the data confirms for the first time in more than two decades that speech errors are common and vary widely up to six years of age.

As part of the study, 1179 participants aged 2-12 years were recruited from schools, childcare centres and kindergartens across Victoria and NSW.

Trained speech and language therapists assessed children using a picture naming task and found developmental speech errors was common in children aged two to six, but by seven years 90 per cent could form all sounds.

Only minor differences in speech were seen between eight and 12 years.

Disordered speech errors that occurred in less than 10 per cent of children included vowel errors, transpositions such as ‘efelant’ for elephant and mixing up speech sounds such as ‘glack’ for black.

Compared with historical data from 20 years ago, some sounds were acquired more slowly and some common errors took longer to resolve. Importantly, there was no evidence that children’s speech had become more disordered.

According to MCRI Professor Angela Morgan, despite speech disorders being an increasing challenge for paediatricians, there is limited evidence to guide detection and referrals for those at risk of persistent problems.

“The lack of research forces a trial-and-error approach, which can result in critical resources being wrongly directed,” Morgan says.

“This is compounded by the absence of any official English speech data being published for over two decades.

“New data is also needed to find out how new technologies, like phones and devices, are changing children’s speech.”

MCRI’s Dr Daisy Shepherd says the large representative study provided a much-needed updated description and understanding of speech performance.

Morgan says the new assessment tool would ensure fewer children were incorrectly assigned to wait lists and less resources wasted on treating speech error patterns that were likely to resolve in time.

“We found lots of young children can struggle to pick up speech correctly, which may explain why so many families seek support for speech development in the preschool years,” she says.

“Furthermore, our data suggests speech is mastered more slowly and common errors are taking longer to outgrow compared with previous generations.

“Our tool identifies the children experiencing the most difficulty within their age group using speech tasks and will support healthcare professionals to improve detection and referral for disordered speech errors.”

Isla, 9, has childhood apraxia of speech, a rare speech disorder that hinders the brain’s ability to plan and co-ordinate the muscle movements necessary for clear speech.

Mum Sheree says Isla was referred to speech therapy at about two years of age after she failed to meet early developmental milestones.

“Isla’s speech was delayed, she wasn’t babbling like babies do and had difficulty starting or transitioning between sounds or words,” Sheree says.

“Luckily at the time, Isla was already seeing a pediatrician who was able to refer us to a speech clinic.

“Despite acting on it quickly, we still had to wait another four months to see a therapist.”

Sheree says the speech therapy has made a significant difference.

“Isla knows what she wants to say in her head, but sometimes her mouth has trouble saying the words clearly and consistently,” she says.

“Her speech difficulty has a huge effect on her confidence. When she was younger, Isla often gave up on talking and relied on non-verbal communication including gestures so others could understand her.

“But with the help of therapy Isla is now better understood, and family and friends have noticed the huge progress in her speech, she has come a long way.”

Sheree says the tool developed by MCRI researchers will be of enormous help to families and healthcare workers.

“We know so many families with children who have apraxia of speech who weren’t able to access early support,” she says.

“Their GPs didn’t refer them to a speech therapist when symptoms first appeared, thinking the child would eventually catch up with their peers.

“On top of that, long wait lists and finding the right therapist fit for your family only adds to the delays.

“Children with speech disorders have to be incredibly resilient but they need early intervention to make sure they can thrive.”

Researchers from the University of Melbourne and Redenlab also contributed to the study.