Babies ‘coo and growl in distinct patterns throughout the first year of life’

Babies squeak and growl in distinct ‘clustering’ patterns throughout the first year of life, new research reveals.

Seemingly random early vocal trials are actually key to speech development, scientists say.

The first large-scale observation of infants’ vocalizations using home recordings throughout the day suggests that they actively engaged in noise play and sound practice.

The American and Austrian research team identified the most common categories of phonation for babies as ‘vocants’ – or vowel-like sounds – ‘scrash’ and ‘growls’.

They investigated whether babies group specific sounds in a non-random way, which would suggest practice or play.

The team analyzed recordings from 130 normally developing English-learning babies recorded throughout the day in their own homes during their first year of life.

A total of 21 five-minute samples were randomly chosen from each child recording.

The researchers categorized every vocalization made in each sample into whoops, squeaks and growls — as well as “other” sounds.

Study co-author Dr. HyunJoo Yoo said: “Forty percent of all squeaks and growls analyzed occurred in significant clusters in all children.”

“Over 60 percent of the five-minute sessions showed a significant amount of clustering focusing on either squeaks or growls, not both in a single session.”

The findings, published in the journal PLoS One, also revealed that 87 percent of the babies showed at least one age at which their recordings had “significant clusters of screeching” and at least one age at which their recordings had “clusters of significant to growl” – none. of infants demonstrating no clustering.

The research team acknowledged that their sound classification approach, while allowing them to collect a large amount of data, likely “oversimplified” the complexities and nuances of babies’ vocalizations.

But they say the data gathered was “enough” to see clear patterns in individual babies as well as across the group, suggesting a possible pathway for language development that warrants further investigation.

Dr. Yoo, an assistant professor at the University of Alabama, said, “Active vocal exploration and vocal category formation are fundamental to later language development.”

She added: “The present study represents the first empirical investigation of the early formation of vowel categories.”

“Babies not only spontaneously produce speech-like vocalizations, but actively explore and practice different types of vocalizations from the first months of life.”