Babies spend a significant portion of their first year making noises, from responding to caregivers with vocalizations to engaging in self-directed babbling.
A new study, published in the open-access journal PLOS ONE, suggests that these seemingly random noises may actually be part of a deliberate process of vocal play and practice. Researchers Hyunjoo Yoo from the University of Alabama, Pumpki Lei Su from the University of Texas at Dallas, and their colleagues analyzed all-day home recordings of 130 English-learning, normally-developing infants and found that the babies grouped specific sounds, such as squeals and growls, in non-random patterns.
Parsing Vocalizations into Categories
The researchers analyzed recordings taken from a larger study conducted by the Marcus Autism Center, Children’s Healthcare of Atlanta, and Emory University School of Medicine. They randomly selected 21 five-minute samples from each infant’s recording and parsed every vocalization made in each sample into categories: vocants (vowel-like sounds), squeals, growls, and “other” sounds. This approach allowed them to collect a large amount of data, albeit with some oversimplification of the complexities and nuances in vocalizations.
Significant Clustering of Squeals and Growls
The analysis revealed that 40 percent of all analyzed squeals and growls appeared in significant clusters across all infants. Over 60 percent of the five-minute sessions showed a significant amount of clustering focused on either squeals or growls, but not both in one session. Additionally, 87 percent of infants demonstrated at least one age where their recordings had significant squeal clustering and at least one age with significant growl clustering. No infants showed a complete absence of clustering.
The clear patterns observed in individual babies and across the entire group suggest a possible pathway for language development that warrants further investigation. The authors note that while their sound categorization approach may have oversimplified the complexities of vocalizations, the quantitative dataset gathered is sufficient to identify these patterns.
“Active vocal exploration and vocal category formation are fundamental to subsequent language development. The present study represents the first empirical investigation of early vocal category formation. Infants not only spontaneously produce speech-like vocalizations, but also actively explore and practice different types of vocalizations from the first months of life,” the authors add.
This study sheds new light on the importance of babies’ babbling and vocalizations in their first year of life, highlighting the potential role of vocal play and practice in language development. As researchers continue to explore this area, their findings may provide valuable insights into how infants acquire language skills and how caregivers can support this process.
