Babies learn to talk by making sounds. But how much do they really babble? A massive review looked at 42 studies involving 1,277 infants aged five to twenty-four months. These babies lived in sixteen different language environments around the world. The goal was to understand how much they babble and what affects that sound.
The data shows a clear pattern. The amount of babbling increases steadily as the child gets older. At five months, the level is low. By twenty-four months, it is much higher. This growth happens in a straight line over time.
How the researchers recorded the sounds mattered. Sessions where parents played interactively with the baby showed more babbling than quiet recordings at home. Also, babies learning languages with complex sounds started with less babbling than those learning simpler sounds. However, all these different paths seemed to meet around the twenty-month mark.
The study has one important warning. Smaller groups of babies were more likely to report higher babbling levels than they actually had. This means some early reports might have been too optimistic. Despite this, the findings support using babbling as a useful sign of development.