Research
Several hundred research studies over the last 50 years document the importance of talking to and
interacting with your baby, especially during the first three years. Many governmental and professional
organizations support the importance of the quantity of talk and conversational turns, including the
National Institute of Child Health and Human Development, American Speech-Language-Hearing Association,
and the Zero To Three Foundation.
Recent brain research also confirms how important parent and caregiver talk is to child development,
which is one reason why the American Academy of Pediatrics recommends that children two years and under
not be allowed to watch TV or videos. It’s not educational toys, TV, or videos that make your child smart
and well-adjusted. It’s you.
Foundational Research: Hart & Risley
One of the most important studies in the field of child development is documented in the book,
Meaningful Differences, by noted University of Kansas researchers, Drs. Betty Hart and Todd Risley.
The remarkable study of parent-child talk and interaction was the inspiration for the development of the LENA
System. Hart and Risley discovered, “With few exceptions, the more parents talked to their children, the faster
the children’s vocabularies were growing and the higher the children’s IQ test scores at age three and later.”
More about this study
Download the latest technical paper from Todd Risley, co-author of Meaningful Differences in the
Everyday Experience of Young American Children.
The Everyday Experience of American Babies: Discoveries and Implications
In response to Dr. Todd Risley’s passing on Nov. 2, 2007:
“We are deeply saddened by the loss of Dr. Todd Risley, whose profound contributions to the field of behavior analysis and human development will be remembered for generations. Todd was a true visionary, dedicated to taking behavioral analysis out of the laboratory and into the community where his research could make a meaningful difference in the lives of so many. He was the inspiration for Infoture’s own research, and we are honored to have collaborated with him and to have learned so much from him. We offer our sincere condolences to Todd’s family and loved ones. He will be immeasurably missed by us all.”
"University leaders offer condolences after death of Todd Risley"
LENA Foundation Research and Technical Reports
Listed below are technical reports to enable researchers and clinicians to better understand LENA’s development, reliability and validity.
View Abstracts
|
Collapse Abstracts
View Archives 
| RSS 
Overview of LENA development and surprising findings, both confirming and expanding on Hart and Risley’s ground breaking work.
permanent link:
http://www.lenafoundation.org/TechReport.aspx/PowerOfTalk/LTR-01-2
This paper describes the multiphase LENA Natural Language Study, an ongoing data collection effort designed to investigate the language environment of infants and toddlers. Data collected contributes to product development and normative information for use with the LENA System and child development research. phase I study participants were representative of the US Census with respect to mothers’ attained education and consisted of 329 normally developing infants and toddlers from monolingual English-speaking households living in the Denver-metro area. participants provided day-long audio recordings of their natural language environment once a month, and certiied speech language pathologists assessed participant language ability independently through standardized assessments. A subset of 80 phase I participants has continued to provide monthly recordings in phase II of the study. The normative database described herein contains over 32,000 hours of spontaneous speech data. This paper describes how normative information was derived for the Adult Word Count estimates (AWC; adult words spoken per day), Conversational Turns estimates (CT; adult-child alternations per day), and Child Vocalization frequency estimates (CV; words, babbles, and “protophones” or pre-speech communicative sounds) that are reported in the LENA System.
permanent link:
http://www.lenafoundation.org/TechReport.aspx/Natural_Language_Study/LTR-02-2
The LENA language environment analysis system was designed to estimate adult and key child interactions in natural home environments. Contrary to controlled clinical research environments, the speech used by the participants in this study was real, unrehearsed, and representative of each child’s typical daily language environment. In this paper, we describe the Audio processing System in terms of information low, feature extraction, and segmentation identiication. We also reveal the audio speciications that were either met or exceeded during the development and design of the LENA digital language processor (DLP).
permanent link:
http://www.lenafoundation.org/TechReport.aspx/Audio_Specifications/LTR-03-2
The LENA Digital Language processor records real-time audio data that is transferred to a computer for processing by LENA language environment software V3.1.0. Ultimately an Interpretive Time Segments (ITS) ile is created that summarizes the processing results for the data contained within the original audio file. LENA data analyses have focused primarily on estimating Adult Word Counts (AWC), Child Vocalizations (CV), and Conversational Turns (CT) between adult and key child. however, the data processing reveals numerous other factors that have not yet been studied by researchers at LENA Foundation. In this paper, we reveal the general content of the ITS file. We also provide a detailed description of each component speciic to the ITS file and implications with regard to potential research and analyses.
permanent link:
http://www.lenafoundation.org/TechReport.aspx/ITS_File/LTR-04-2
The LENA language environment analysis system was designed to provide information about the language environment of infants and toddlers. In this technical report, we describe the reliability of the LENA System in terms of segmentation, adult word counts, and child vocalizations. We also describe unique sources of variability associated with data collection in the natural home environment.
permanent link:
http://www.lenafoundation.org/TechReport.aspx/Reliability/LTR-05-2
The developing of the LENA language environment analysis software V3.1.0 as well as quantifying its accuracy and reliability is dependent on the accurate and reliable transcription of the audio recording files by professional transcribers. here, we discuss the analytical procedure designed and implemented by LENA’s professional transcription team to identify and code speakers. We also reveal the degree to which inter-rater reliability was achieved between the criterion rater and four to seven secondary raters in terms of agreement for segment classiication and adult word counts. Signiicant accuracy in the transcriptions was critical to train the processing models used to identify segments in audio recordings automatically and subsequently to test the accuracy and reliability of the segmentation process.
permanent link:
http://www.lenafoundation.org/TechReport.aspx/Transcription/LTR-06-2
As part of the development of the LENA System, a team of LENA speech language pathologists, linguists, statisticians and other researchers created the LENA Developmental Snapshot (LDS). This 52-item survey was designed to assess expressive and receptive language skills in children 2 months-36 months of age and to estimate developmental age as a function of chronological age. here we describe the development of the LDS. Initial respondents were drawn largely from the LENA Normative Study participant pool, and their LDS scores were validated based on correlations with pre-existing standardized language and cognitive assessments. participants in a longitudinal study completed the LDS at approximately monthly intervals to evaluate LDS test-retest reliability.
permanent link:
http://www.lenafoundation.org/TechReport.aspx/Snapshot/LTR-07-2
This report describes the development of LENA’s automatic vocalization assessment (AVATM) software. AVA software is designed to provide both parents and professionals with automatically generated information about the expressive language development of children ages 2 months to 48 months. Expressive language estimates are produced based on 12- to 16-hour audio recordings collected in the natural home environment using the LENA language environment analysis system. AVA software uses automatic speech recognition technology to categorize and quantify the sounds in child vocalizations (e.g., protophones and phonemes). These quantitative acoustic information data (expressed as “phone” and “biphone” frequencies) are reduced to principal components which are applied as input for age-based multiple linear regression models. The AVA software utilizes these regression models to generate information about expressive language development as standard scores, developmental age estimates, and estimated mean length of utterance (EMLU). AVA expressive language estimates demonstrate statistical reliability and validity comparable to standard expressive language assessments commonly administered by speech language pathologists.
permanent link:
http://www.lenafoundation.org/TechReport.aspx/AVA/LTR-08-1
The LENA language environment analysis system is a powerful new tool that can help pediatricians, speech language pathologists, and audiologists improve their diagnosis and treatment of language delay and disorders, and increase parent involvement and satisfaction. Broadly speaking, the uses of LENA in clinical practice fall into four categories: 1) assessment and diagnosis, 2) monitoring fidelity of treatment, 3) audio environment analysis, 4) enhanced treatment through in-home feedback.
permanent link:
http://www.lenafoundation.org/TechReport.aspx/ClinicalApps/LTR-09-1