Like a musician tuning a guitar, adults subconsciously listen to their own voice to tune the pitch, volume and pronunciation of their speech. Young children just learning how to talk, however, do not, a new study suggests. The result offers clues about how kids learn language—­and how parents can help.

Past studies have shown that adults use aural feedback to tweak their pronunc­iation. Ewen MacDonald, a professor at the Center for Applied Hearing Research at the Technical University of Denmark, decided to see if toddlers could do this as well. He had adults and children play a video game in which they guided the actions of a robot by repeating the word “bed.” Through headphones, the players heard their own voice every time they spoke—but with the frequency spectrum shifted so they heard “bad” instead of “bed.” MacDonald found that adults and four-year-old kids tried to com­pensate for the error by pronouncing the word more like “bid,” but two-year-olds never budged from “bed,” suggesting that they were not using auditory feedback to monitor their speech.

Although the toddlers may have been suppressing the feedback mechanism, MacDonald thinks they might not start listening to themselves until they are older. If that is the case, they may rely heavily on feedback from adults to gauge how they sound. In­deed, most parents and caregivers naturally repeat the words toddlers say, as praise and encouragement. “I think the real take-home message is that social interaction is important for the development of speech,” MacDonald says. “The general act of talking and interacting with the child in a normal way is the key.”

This article was published in print as "Learning to Listen."