TUSCALOOSA, Ala. — From gurgling “goos” to squealing “wheees!”, the delightful symphony of sounds emanating from a baby’s crib may seem like charming gibberish to the untrained ear. However, a new study suggests that these adorable vocalizations are far more than just random noise — they’re actually a crucial stepping stone on the path to language development.
The research, published in PLOS One, took a deep dive into the vocal patterns of 130 typically developing infants over the course of their first year of life. Their discoveries challenge long-held assumptions about how babies learn to communicate.
Traditionally, many experts believed that infants start out making haphazard sounds, gradually progressing to more structured “baby talk” as they listen to and imitate the adults around them. This new study paints a different picture, one where babies are actively exploring and practicing different categories of sounds in what might be thought of as a precursor to speech.
Think of it like a baby’s very first music lesson. Just as a budding pianist might spend time practicing scales and chords, it seems infants devote chunks of their day to making specific types of sounds, almost as if they’re trying to perfect their technique.
The researchers reached this conclusion after sifting through an enormous trove of audio data captured by small recording devices worn by the babies as they went about their daily lives. In total, they analyzed over 1,100 daylong recordings, adding up to nearly 14,500 hours – or about 1.6 years – of audio.
Using special software to isolate the infant vocalizations, the research team categorized the sounds into three main types: squeals (high-pitched, often excited-sounding noises), growls (low-pitched, often “rumbly” sounds), and vowel-like utterances (which the researchers dubbed “vocants”).
Next, they zoomed in on five-minute segments from each recording, hunting for patterns in how these sound categories were distributed. The results were striking: 40% of the recordings showed significant “clustering” of squeals, with a similar percentage showing clustering of growls. In other words, the babies weren’t randomly mixing their sounds, but rather, they seemed to focus on one type at a time, practicing it intensively.
Even more fascinating, this clustering pattern cropped up in babies of all ages, even in the very first months of life. Interestingly, the three to four-month mark (often thought of as the peak of “vocal play”) actually had the lowest rates of clustering. The practice sessions seemed to ramp up as the babies got older, with the most focused “rehearsals” happening in the second half of the first year.
So why does this matter? The researchers believe this vocal exploration serves two key purposes. First, it helps lay the neurological groundwork for speech. After all, as any adult learning a new language knows, mastering unfamiliar sound categories is a crucial part of the process. By spending time practicing different vocalization types, babies may be priming their brains for the challenge of speech acquisition.
Second, all this “baby talk” may serve as an important signal to caregivers. A baby who spends a chunk of time squealing or growling is, in a sense, showing off their vocal prowess. To an attentive parent, these concentrated bouts of a particular sound could be a sign that the baby’s development is on track and perhaps even a cue to engage the baby in some back-and-forth “conversation.”
Of course, like any good science, this study raises as many questions as it answers. The researchers readily acknowledge the limitations of their baby sound “coding system,” which boiled down an incredibly complex set of vocalizations into just a handful of broad categories.
They also note that their method of sampling — analyzing five-minute snippets from daylong recordings — likely underestimates the true number of vocal practice sessions. A baby may have many more “cluster” bouts that simply didn’t make it into the analyzed segments.
Still, the work represents a major leap forward in our understanding of how babies develop the building blocks of language. It suggests that infants are not just passive recipients of language input but active explorers, shaping their own vocal development through diligent (and adorable) practice.
So, the next time you hear a baby babbling away in what sounds like nonsensical streams of squeals and growls, listen closer. That little one may be working hard on their pre-language “scales and arpeggios,” preparing for a lifetime of communication. If you can’t resist joining in the “conversation,” go right ahead — the baby will likely welcome the duet.
StudyFinds Editor-in-Chief Steve Fink contributed to this report.