Canonical babbling trajectories across the first year of life in autism and typical development

Abstract

This study explores vocal development as an early marker of autism, focusing on canonical babbling rate and onset, typically established by 7 months. Previous reports suggested delayed or reduced canonical babbling in infants later diagnosed with autism, but the story may be complicated. We present a prospective study on 44 infants later diagnosed with autism spectrum disorder compared with 127 infants later identified as typically developing who were followed longitudinally with day-long recordings from 0 to 13 months. Eight 5-min segments from each of their recordings were coded for canonical and noncanonical syllables. The results confirmed many reports that canonical babbling is a robust feature of human vocal development in the first year of life, with small overall mean differences in canonical babbling rates between the autism spectrum disorder and typically developing groups beginning around 9 months, primarily in males. Our findings highlight the importance of considering sex differences in vocal communication as part of the early detection and diagnosis of autism when determining the need for communication supports to maximize outcomes. Lay Abstract Our study examined how babies develop their ability to talk to help identify early signs of autism. We looked at babies’ production of babbling with mature syllables across the first year of life. Babies usually start producing mature babbling at 7 months of age before they say their first words. Some studies have suggested that babies who are later diagnosed with autism produce this kind of babbling less frequently in their first year of life, but other studies have shown complicated outcomes. In this new study, we followed 44 autistic babies and compared them to 127 typically developing babies. We recorded the babies once every month, all day long, from the time that they were born until they were around 13 months old. Then, we studied their mature babbling from segments of these recordings. We found that the rate at which babies used mature babbling was lower in boys with autism, and higher in girls with autism, compared to babies without autism. This research helps us understand how babies with autism learn to talk. It also raises important questions about differences between boys and girls with autism. Our study can help us improve how scientists and clinicians can identify autism earlier, which could lead to better communication supports for autistic children and their families.