Lower Hutt mum Sarah Mahy says the Canterbury University study might clarify for her how concerned she should be about her children's speech.
Two of her three children have had help with their speech - with one still getting therapy. They were both about 2 when Ms Mahy and her husband noticed their speech wasn't as developed as others'.
"Alfie had really good vocabulary, but his clarity wasn't that flash - he would say 'sanks' for 'thanks', which triggered some concerns when we took him to the speech therapist."
He had treatment and now, at 5, his speech is fine.
Louie is now 2 and has made good progress, but last week his Plunket nurse put him back on the public health list for some extra help.
He had suffered from glue ear and might need grommets again.