A mother's voice changes while talking to her newborns

Washington D.C.: A study has recently found that mothers">new mothers subconsciously change the tone of their voice when they talk to their babies so that their babies can learn to recognise their mothers from birth.

According to researchers from the Princeton University in New Jersey, U.S., regardless of the language spoken, all mothers use a universal 'motherese' or 'baby talk' when they address to their infants, which is an exaggerated and somewhat musical form of speech.

While it may sound silly to adults, studies show it plays an important role in language learning, engaging infants' emotions and highlighting the structure of language to help babies decode the puzzle of syllables and sentences.

The researchers explained that a mother shifts the timbre, which is defined as the quality of a sound, in her voice so her newborn can recognise and pay attention to her from birth.

The team recorded the mothers when they played with their seven- to 12-month-old newborns and when they spoke to another adult.

The findings indicated that the differences in timbre were strong enough to be reliably picked out by a machine learning algorithm.

The authors explained that the shifts suggested there was a universal form of communication with newborns.

Researcher Elise Piazza said her team had discovered 'a new cue that mothers implicitly use to support babies' language learning'.

The timbre shift was consistent across women who spoke 10 languages: English, Cantonese, French, German, Hebrew, Hungarian, Mandarin, Polish, Russian and Spanish.

Piazza said: 'We found that mothers alter this basic quality of their voices when speaking to infants, and they do so in a highly consistent way across many diverse languages.'

The study was published in the Current Biology journal.