Toddlers Hear Their Own Words Differently, Says Study

Ever wonder why toddlers just can't seem to get the pronunciation of some words just right? Science may now have an answer.

People subconsciously monitor their voices to ensure the sound they are producing is the one that is intended. If it is different, we are able to change that tone, but new research found that toddlers do not monitor their voices in the same way.

"Surprisingly, 2-year-olds do not monitor their auditory feedback like adults do, suggesting they are using a different strategy to control speech production," lead author Ewen MacDonald of the Technical University of Denmark told

MacDonald said monitoring one's voice is similar to musicians playing music. For example, violinists adjust their fingers to bring a note that is out of tune, in tune.

In the study, published in the journal Cell Biology,  a group of adults, 4-year-olds, and 2-year-olds said the word "bed" repeatedly while simultaneously hearing the word "bad" through a set of headphones. Everyone was able to adjust their speech to continue to say the word "bed," except for the youngest age group.

The findings are surprising because infants can detect small changes in the pronunciation of familiar words in their native language, MacDonald said. By the time American children reach age 2, they have an average of 300 words in their vocabulary.

One reason for the findings may be due to the way children communicate with their caregivers, researchers noted.

"One possibility is that the 2-year-olds may rely on the person they are talking to instead of monitoring their own voice," said MacDonald. "If you look at interactions between young toddlers learning to speak and their caregivers, you will often hear the caregiver repeating or reflecting back what the child has just said.  It may be this interaction that is helping children judge their accuracy in producing speech."

But Diane Paul, director of clinical issues in speech-language pathology at the American Speech-Language-Hearing Association, said the task itself may be too challenging for this age.

"They don't have the linguistic experience and developmental ability yet to self-correct," said Paul. "Young children may mispronounce certain sounds (sounds that typically develop later). But if an adult asks them, "Did you say (sound pronounced correctly), they will say 'yes.' They hear the sound correctly even though they are not yet ready to pronounce it correctly."

The study confirms what researchers have known about typical development, Paul continued. Young children focus on the content of what they are saying rather than the way they are saying it. Children develop the ability to "repair conversations" when they are misunderstood starting around age 3. These skills are refined as children get older, she said.

"Our work highlights the importance of social interaction, such as conversation between caregivers and children, in the development of children's speech production," said MacDonald. "While the present study focused on the normal development of speech production, we will be investigating potential applications for understanding and addressing delayed and abnormal early speech development."

To help build their children's language, parents should focus on what their young children say rather than how they say it, Paul said.  If a child has a speech error, parents should say the sound correctly in their own speech, but they should not correct the child in the early stage of speech development.

Paul gave the following notes and tips for parents to understand their children's language development:

Children do not learn to say all speech sounds at once. They say sounds in a predictable sequence depending on the particular language or language they are learning.

Be a good speech model. Speak clearly and use correct speech sounds.

Respond to any of a child's attempts at communication.

Show that you are listening and comment on what your child says, not how he or she says it.

Talk and read to your child often to stimulate speech, language and listening skills.