By Kelley Dwyer, Au.D., CCC-A
Pediatric Audiologist

Current research has proven that parents’ interactions with their infants and toddlers are vital to proper speech and language development. Not only does this parent-child interaction foster appropriate language acquisition and expansion, it is also a reliable predictor of a child’s future success.

Based on research conducted by Betty Hart and Todd Risley in 2003, language exposure varied widely between socio-economic classes. The language experience was not influenced by amount of toys, but was instead solely determined by the quantity and quality of communicative interaction between the parent and child. Their research, based on observations of 42 families and their children across the socio-economic spectrum from infant to three years showed that the amount of words heard by a child in a family of low socio-economic status was significantly lower in quantity and quality, than those heard by a child on the other end of the spectrum.

The average child at the low end of the continuum heard approximately 616 words per hour versus a child from a family of high economic standing, who heard an average of 2,153 words per hour. The data, extrapolated out to the fourth year of life, showed that the child from the family of high economic standing would hear approximately 45 million words in four years. Conversely, an average child from a family of low economic status would top out at 13 million words at the age of four, a difference, and deficit, of 30 million words.

The observers also found that a child’s vocabulary, sentence structure, and speech patterns were almost identical to their caregivers, with 86% to 98% of a child’s vocabulary being derived directly from their parents. Furthermore, the same children were re-evaluated at the age of nine and results indicated that those children who were subjected to the 30 million word gap were still performing at a significantly lower level in areas of vocabulary, language development, and reading comprehension abilities, than their peers who were given access to a language-rich environment.  This static pattern of lower performance suggests that the language skill discrepancies have not been resolved after four years of classroom education and may actually indicate widening gaps. This continuing trend identifies language abilities, established by the age of three and gleaned from parent-child interactions, to be a good predictor of future capacity.

Parents must be empowered to positively influence their child’s speech and language development from early infancy, as they hold the key to impact not only their child’s linguistic capabilities, but also their future cognitive potential. A parent has the unique opportunity, while a child is young and dependent, to shape every experience they encounter. As a result, these early exposures will create the foundation for the child’s habits in attending to, categorizing, and integrating newer and more complex experiences in the future.

Grow Your Baby’s Brain

The common link between successful school-age children has little to do with the amount of toys, or cool gadgets they have. Once a student reaches third grade (nine to ten years of age) a child transitions from “learning-to-read” to “reading-to-learn.” If language/reading skills are not up to par at this age, the language gap will be difficult to close, resulting in increased difficulty in the classroom for the rest of the child’s education.

Research has shown that parent-child interaction is the one key for fostering great speech and language development by age three. Cortical development, influenced significantly by experiences, occurs most rapidly in infancy and early childhood. As a result, parents and caregivers can actually influence the growth of their baby’s brain.

Parents speak to their babies in a natural way with small sentences, elongated vowels, more inflection, and at a higher pitch, typically referred to in literature as parentese.  Parentese differs from the commonly known term of baby talk, which consists  of syllables that are unintelligible and do not form actual words.

Research has shown that infants and young children were able to connect words to their objects with more ease when spoken to using parentese. Although your baby may not understand you, it is imperative for you to sing and to talk to your child, so the child is exposed to the sounds and structure of their native language.

During this time a child learns which mouth movements coincide with different sounds, demonstrating the importance of face-to-face interaction. Furthermore, this interaction, and turn-taking that occurs naturally between you and your baby, mimics typical human conversation, shaping the understanding of cultural dialogue.

Repetition of words strengthens your child’s ability to produce that word, give it meaning, and categorize it in the understanding of other words. As a parent you can create a language-rich environment by narrating your child’s daily activities. By linguistically highlighting your child’s  actions and experiences, you can allow your baby to follow along and draw connections between words and their meanings.

For example, statements like “Mommy is cooking dinner,” “Carrots are orange and yummy,” “Socks go on your feet,” and “Bubbles are fun in the bath,” can help your child pay attention to daily details. Even reading to your baby, along with talking about the pictures and characters, will give your baby the benefit of correlating your words and assumptions with their meanings and concepts. By actively growing your baby’s brain and practicing good language nutrition, you can significantly impact the development of your child’s speech and language development, along with future educational and cognitive paths.

 Bridging the Gap 

The 30 million word gap was a monumental finding from Hart and Risley’s research, demanding that parents strengthen their interactions with their infant children and take responsibility for nurturing their speech and language development.   Organizations like the 30 Million Word Project and Project ASPIRE are actively trying to bridge the gap and resolve the discrepancies, working towards a common goal of age-appropriate speech and language development by the age of three.

By providing parent-directed counseling, these organizations aim to empower parents with the knowledge that they hold the key to their child’s language development and future success. Utilizing parent-implemented intervention, the 30 Million Word Project and Project ASPIRE are entering homes and enriching the language environments of children, through their caregivers. Similar programs, with goals of increasing language input in the home through parent interaction, include the Marcus Autism Center’s “Talk with Me Baby” and the Hanen Program “It Takes Two to Talk.” For more information on how to provide your child with a language-rich environment, please visit the websites below, including the TedX talk on Language Nutrition by Dr. Brenda Fitzgerald, Commissioner of the Georgia Department of Public Health.

As a parent you are your child’s best advocate for speech and language development.


Hart, B. & Risley, T.R. “The Early Catastrophe” (2004). Education Review, 77 (1), 100-118

Suskind, D, & Leffel, K. “The Thiry Million Word Project: A Quantitative Study.” (2013). Lecture.

Suskind, D., et al. “An Exploratory Study of “Quantitative Linguistic Feedback”: Effect of LENA Feedback on Adult Language Production” (2013). Communication Disorders Quarterly, 34.4, 199-209. Web. 

 Werker, J. F. “Infants prefer” parentese.” (1987) Society for Research in Child Development Meeting, April, 23.