Washington, Oct 13 (PTI) Women tend to shift the timbreof their voice in a specific way while speaking to theirbabies, which could play an important role in the child'slanguage learning, a study suggests.
When talking with their young infants, parentsinstinctively use "baby talk," a unique form of speechincluding exaggerated pitch contours and short, repetitivephrases.
"We use timbre, the tone colour or unique quality of asound, all the time to distinguish people, animals, andinstruments," said Elise Piazza from Princeton University inthe US.
"We found that mothers alter this basic quality of theirvoices when speaking to infants, and they do so in a highlyconsistent way across many diverse languages," said Piazza.
Piazza and her colleagues focused on the vocal cues thatparents adjust during baby talk without even realising theyare doing it.
The researchers recorded 12 English-speaking motherswhile they played with and read to their 7- to 12-month-oldinfants. They also recorded those mothers while they spoke toanother adult.
After quantifying each mother's unique vocal fingerprintusing a concise measure of timbre, the researchers found thata computer could reliably tell the difference between infant-and adult-directed speech.
Using an approach called machine learning, theresearchers found that a computer could learn todifferentiate baby talk from normal speech based on just onesecond of speech data.
They verified that those differences could not beexplained by pitch or background noise.
The next question was whether those differences wouldhold true in mothers speaking other languages.
The researchers enlisted another group of 12 mothers whospoke nine different languages, including Spanish, Russian,Polish, Hungarian, German, French, Hebrew, Mandarin, andCantonese.
They found that the timbre shift observed in English-speaking mothers was highly consistent across those languagesfrom around the world.
"The machine learning algorithm, when trained on Englishdata alone, could immediately distinguish adult-directed frominfant-directed speech in a test set of non-Englishrecordings and vice versa when trained on non-English data,showing strong generalisability of this effect acrosslanguages," Piazza said.
"Thus, shifts in timbre between adult-directed andinfant-directed speech may represent a universal form ofcommunication that mothers implicitly use to engage theirbabies and support their language learning," said Piazza. PTISARSAR.
This is unedited, unformatted feed from the Press Trust of India wire.