Before babies start saying words, it is hard for parents to know whether their little one actually understands the things that they say to them. Many parenting magazines and books recommend speaking to children even before parents think their babies can understand what they're saying – and sometimes even before they're born – because it helps babies to recognise voices and begin to learn about language. You may wonder, though, if a baby has no idea what is being spoken to them, does it really matter what or how it is said?
It might be useful to know that babies do actually understand something about what you're saying before they know what the words themselves mean. In fact, "baby talk" – when you exaggerate emotions and extend words more than you usually would with adults – can be useful for helping babies distinguish speech sounds.
In addition, we know that a mothers' tone of voice, as well as singing, can soothe infants, reducing their levels of cortisol, a hormone produced when experiencing stress. Research also increasingly suggests that babies pick up on, and respond differently to, tones of voice. It may even be that the tone used when speaking to babies can give them information about what the speaker intends for them, and motivates them to behave in certain ways.
Studies have also confirmed that babies can distinguish between positive and negative messages at as young as five months old. You may have noticed, for example, how babies respond when they hear a sharp "No!" to warn them away from danger, or how speaking in a calming voice can soothe little ones. Babies also respond differently to toys depending on whether their parents talk about the objects using positive or negative sounding voices. The babies are more likely to approach a toy they've never seen before when they hear a positive tone, for example, even if the words spoken are exactly the same.
Motivated by tone
Our latest research project seeks to find out more about how babies are motivated by these different tones of voice. When a parent or a nursery teacher speaks to a baby, they naturally adjust their tone of voice. Whether they are encouraging babies to try something new, avoid something dangerous, or cooperate on a task, caregivers seem to use various tones to help babies understand their intention.
We know that by the time a child begins school, these motivational "messages" can influence how well they do in education, how happy they are, and even how or if they behave in aggressive ways with other children. But researchers know very little about whether babies care about, or are affected by, the motivational messages that come from encouraging tones of speech.
Why does it matter whether babies respond to motivational messages? Well, as a multi-tasking parent or childminder, it can be challenging to convey information to a preverbal baby in an efficient way.
To carefully explore this, we are now planning research with babies aged between ten and 12 months and their families. During the study, we will show the babies simple pictures on a screen and play short sentences. We will then measure how long the infants listen to sentences that are spoken in different tones.
Technology allows us to track exactly where and how long each baby watches the screen in front of them, and we can show the parents how we measure this as soon as the study ends. It may not sound like much fun for the little ones, but we have designed it to be playful and engaging, and the study is held in a friendly and safe environment.
If we find out that a simple change in the tone of voice can stop young babies from doing something that could be dangerous, or encourages them to engage in a positive behaviour, this could be an efficient route to communicating with and helping all children to learn. It could also lead to happier babies who are more effectively motivated by their caregivers.
Sarah Gerson, Lecturer in Developmental & Health Psychology, Cardiff University; Merideth Gattis, Professor of Psychology, Cardiff University, and Netta Weinstein, Senior Lecturer in Social and Environmental Psychology, Cardiff University