Tone More Important than Phonetics for Babies’ Language Development 

A new study by the University of Cambridge, has found that sing-song speech is vital in helping babies to learn a language and that babies do not begin to process phonetic information (the smallest sound units of speech) until they are around 7 months old.

The study concluded that the rise and fall of tone—as in a nursery rhyme—is crucial to an infant’s processing of information and language.

The new findings, published in Nature Communications journal, directly challenge the view that phonetic information is the most critical part of infant language learning. Phonetic information is typically represented by alphabetic sounds.

When processing their findings in relation to levels of development, the team explained that the results suggest dyslexia and developmental language disorder may be associated with rhythm perception, as opposed to difficulties with processing phonetic information.

Professor Usha Goswami, a neuroscientist at the University of Cambridge and author of the study, explained “Our research shows that the individual sounds of speech are not processed reliably until around seven months, even though most infants can recognize familiar words like ‘bottle’ by this point.”

“From then individual speech sounds are still added in very slowly—too slowly to form the basis of language. We believe that speech rhythm information is the hidden glue underpinning the development of a well-functioning language system.” 

“Parents should talk and sing to their babies as much as possible or use infant-directed speech like nursery rhymes because it will make a difference to language outcome.”

Previous studies have led linguists to believe that infants pick up small sound elements first, and then add them together to make words.

To put this theory to the test once again, the Cambridge researchers recorded the brain activity of 50 infants at ages: four, seven, and 11 months old,  as they watched a video of an elementary school teacher singing 18 nursery rhymes.

The team then used tailored algorithms to distinguish how the infants were encoding and processing this information in the brain.

Subsequently, the collected data showed that phonetic encoding in babies emerged gradually over the first year of life, beginning with dental sounds (produced by the upper front teeth)—such as “d” for “daddy” and “t” for “teddy”; —and nasal sounds (produced when airflow is directed through the nose) —such as “m” for “mommy”.

Professor Goswami added : “Infants can use rhythmic information like a scaffold or skeleton to add phonetic information on to. “For example, they might learn that the rhythm pattern of English words is typically strong-weak, as in ‘daddy’ or ‘mommy’, with the stress on the first syllable.”

“They can use this rhythm pattern to guess where one word ends and another begins when listening to natural speech.” 

She expressed that rhythm is a universal aspect of every language, whereby all babies “are exposed to… a strong beat structure with a strong syllable twice a second” and concluded, “We’re biologically programmed to emphasize this when speaking to babies.”