To measure how babies learn from baby talk, Dr. Patricia Kuhl of the University of Washington and colleagues in Sweden and Russia had babies listen to both adult speech and to their mothers’ slower baby talk.
Adult speech is faster, more monotone and few of the vowels are articulated clearly. Kuhl recorded an adult saying, “I bought this set of beads and I like them.” The word, “bead,” came out sounding like “bid,” or “bit,” or “bed.”
In baby talk, or “parentese,” the word was stretched to “beeeeeeeed!” The voice was high, sing-songy and positive, and the mothers’ faces were expressive, the mouth over-exaggerating - which shows the baby how to form the sound.
Babies in the study were far more attracted to the baby talk and paid attention longer. Earlier studies show infants’ hearts beat faster and more endorphins are released when listening to baby talk like “Loooook at the red baaaaaahhl!” and “Give me a biiiiiiig smiiiiile!”
“This is biology telling us something, that it comes naturally for us to talk to our infants in this way,” Kuhl said. “You couldn’t instruct it if you tried.”