Glossary

An Adult Word Count (AWC) is the number of words a child hears from an adult within a specific period of time: 5 minutes, hourly, daily. Studies show an increase of Adult Word Count can lead to an increase in a child’s later language and academic success.

AVA is an automatic assessment, based on the analysis of the audio recording of a child. AVA measures a child’s expressive language, provides Estimated Mean Length of Utterance (EMLU), and estimates the child’s language development age. AVA also provides a standard score, that has a high correlation to the REEL and PLS, at .73.

A child vocalization is counted when a child-speech of any length is surrounded by greater than 300 milliseconds of silence or other sound which is not child-speech. Child Vocalizations do not include cries or vegetative sounds. Examples:
   Child speaks: (pause) “baba baba baba baba” (pause)
   Child speaks: (pause) “but mama, I want the kitty now!” (pause)
   Child speaks: (pause) “not that, (pause) I want that” (pause) Some examples of child vocalizations are:

1. Canonical syllables: Baba, dada
2. Protophones: squeals, growls, raspberries etc.
3. Language dependent words and utterances

A Conversational Turn occurs when a child vocalizes (initiates) and an adult responds, or an adult speaks (initiates) and a child responds. Each time that happens, one turn is counted. CT’s are the only way to measure engaged interaction with a child, in order to enhance speech and language. Studies show an increase of Conversational Turns can lead to an increase in a child’s later language and academic success. Example: Child Initiates: “ba de do ba” and Adult Responds: “That’s right, that’s your bottle.” = One conversational turn Example: Adult Initiates: “Are you playing with your bear?” and Child Responds: “My bear.” = One conversational turn

The LENA Developmental Snapshot is an age-appropriate questionnaire that gives an estimate of a child’s developmental age, compared to their chronological age. LENA scientists and speech language pathologists developed the questionnaire, which is reliable and valid, and is highly correlated to standardized developmental assessments.
For more information, please reference LTR-07: The LENA™ Developmental Snapshot located on the LENA Foundation Technical Reports Page.

A two-ounce device developed to record your child’s language environment in order to provide you with feedback.

Estimated Mean Length of Utterance (EMLU) is a measurement, originally formalized by psychologist Roger Brown in 1973. EMLU is used based on the theory that states: since the length of the child’s utterances increases with age, one can derive a reasonable estimate of a child’s linguistic sophistication by calculating the average length of his/her utterances.

Written by LENA Foundation scientists, these technical reports provide detailed information about LENA’s development, reliability and validity. Current topics are listed below and are available on the LENA Foundation Technical Reports Page: LTR-01: The Power of Talk
LTR-02: The LENA Natural Language Study
LTR-03: The LENA™ Language Environment Analysis System: Audio Specifications
LTR-04: The LENA™ Language Environment Analysis System: The Interpreted Time Segments (ITS) File
LTR-05: Reliability of the LENA™ Language Environment Analysis System in Young Children’s Natural Home Environment
LTR-06: Transcriptional Analyses of the LENA Natural Language Corpus
LTR-07: The LENA™ Developmental Snapshot
LTR-08: The LENA™ Automatic Vocalization Assessment
LTR-09: Clinical Applications of the Breakthrough LENA System: Monitoring Language in the Natural Environment of the Child
LTR-10: Development and Performance of the LENA Automatic Autism Screen

The LENA Clothing is specifically designed for consistent and optimal acoustic properties, as well as the child’s comfort. The clothing is a critical part of using the LENA System. The LENA Digital Language Processor (DLP) fits snugly and unobtrusively into the pouch hidden in the front chest pocket, which is made out of special materials to allow audio to come through. The placement of this pocket was designed based on the distance and proximity of the key child’s mouth.

Test to evaluate a child’s language development, commonly administered by a speech language professional.

Test to evaluate a child’s language development, commonly administered by a speech language professional.

A standard score (SS) is a statistic that expresses how much a particular child’s score deviates from the average score of the test group. It is measured in standard deviation units. The standard score that LENA reports is much like those of the PLS. The scores are scaled to have a mean of 100 and a standard deviation of 15. Thus, a child with an SS=115 is scoring one standard deviation above the mean, roughly the 84th percentile. A child with a SS=70 is scoring 2 standard deviations below the mean, or in the delayed range.