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Lots of people automatically speak to babies with a 'baby voice', using a sing-song rhythm and silly sounding words like 'bunny' and 'doggy'. But how does this affect the way babies learn language?

Researchers at the University of Cambridge are investigating the effects of ‘baby talk’ on babies' brains. They’ve found that the rhythm we use when we speak to babies is important to language learning, and that baby talk emphasises a rhythm that really helps children to learn words quickly.

We caught up with Professor Usha Goswami, who is leading on the project, to find out more.

Why is the rhythm of baby talk good for babies?

Image caption,
Cambridge University Professor, Usha Goswami set up an experiment to find out the best way to talk to a baby.

“In the Baby Rhythm Project, we've been following 120 infants over the first 2 and a half years of their life to see how important rhythm is in the development of language,” says Usha. They’ve been testing how babies’ brains respond to ‘baby talk’ with it’s sing-song rhythm versus normal speech.

Our data suggest that rhythm is fundamental to language learning - both being spoken to in baby talk, which has exaggerated rhythm structures, and a lot of the interactions we do with babies, like bouncing them on the knee or singing. All of those kinds of rhythm seem to be important for how babies learn language.

We tend towards the same rhythm when we speak in baby talk, she says. “We've looked at the way in which mums talk to babies in different languages and unconsciously they're exaggerating a rhythm pattern of around 120 beats a minute.” This is perfect for babies to learn from it seems. Her team’s experiments have shown that babies’ brainwaves seem to work in sync with this rhythm of speech. “We measured the brain response from 2 months, and it was always strongest to speech at that rhythm.”

Usha explains further. “Basically, the brain works by rhythm. You've got brain cells in large networks that are signalling using these pulses of electricity. You could think of this like fireflies in the forest. Each firefly is flickering on and off with a little pulse of electricity, but it's all random. But if you imagine someone in that forest playing a drum and all of the fireflies deciding to go on and off in time with that drumbeat, that's what your brain does [when it hears the rhythm of speech].”

It just so happens that the most common rhythm in human speech is the one we emphasise when we speak to babies. “Human speech is the most complex sound signal the brain receives, and there are many different rhythms to it, but the dominant rhythm is this 120 beats per minute that we exaggerate in baby talk. So this seems a great place for baby’s brains to start. We do it unconsciously, but it seems to be very important for the learning brain.”

Image caption,
Cambridge University Professor, Usha Goswami set up an experiment to find out the best way to talk to a baby.

Are words like ‘doggy’ and ‘bunny’ good for babies too?

Image caption,
The team looked to find out what's happening inside babies' brains when they listen to Parentese. Parentese is a way of speaking that heightens pitch, exaggerates the length of words and is very rhythmic.

When we speak to babies, we tend to use lots of versions of words that aren’t quite correct English, things like ‘doggy’, ‘bunny’ and ‘mummy’. It might seem odd, but Usha says that these are helpful for children learning to speak compared to using the ‘proper’ words. This is because they make the rhythm pattern of speech really obvious and clear. “When we speak, we usually alternate between strong and weak syllables. Our voices go up and down in loudness. In baby speak, we naturally emphasise that rhythm more than ever: ‘Dad-dy’, ‘mum-my’, ‘ba-by’.

Usha says that these words are much easier for babies to pick out and recognise when adults speak to them “When adults speak, our language is often a constant stream, there are no gaps when we're talking so you have to learn where to cut word from word. A good way to do this is to tune into that strong/weak pattern, which is so clear in words like ‘Daddy’, ‘Mummy’, ’doggy’, ‘kitty,’” she says. When babies are able to clearly pick words out in this way, they’re more likely to remember them.

This is another thing we do unconsciously when talking to babies, but which really aids their language learning.

When we make the sound patterns fit that template of ‘strong/weak/strong/weak’, then we’ve taken away one level of difficulty in learning a language.
Image caption,
The team looked to find out what's happening inside babies' brains when they listen to Parentese. Parentese is a way of speaking that heightens pitch, exaggerates the length of words and is very rhythmic.

How do nursery rhymes help?

Image caption,
Children's brain signals pulsed in time with the sing-song rhythms of baby talk.

Not only do we speak to babies in an exaggerated way, but adults often sing songs to babies from birth, particularly nursery rhymes. Usha is clear on the benefits of this. “I think nursery rhymes are fundamentally important because they present perfect rhythm structures. When adults speak to one another, we're not being rhythmically regular. But when you're singing to somebody, you're timing your language to an external beat, which helps children to predict the rhythm. In a nursery rhyme, which has a very simple rhythm pattern, babies get this especially good framework for learning about language.”

Usha says that the tradition of singing to babies and exaggerating rhythm patterns in our speech dates back to early human life and has evolved over time to the way we speak to babies today in a way that boosts their brains’ abilities to learn language. Food for thought the next time you sing ‘Wheels On The Bus’ or ask your baby what the ‘doggy’ is doing.

Image caption,
Children's brain signals pulsed in time with the sing-song rhythms of baby talk.

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