Product Development

Inspired by research on child development, especially Meaningful Differences by Drs. Hart and Risley, Infoture’s world-class team of engineers, research academicians, linguists, and speech-language professionals spent three years and millions of dollars researching and developing the LENA System.

A simple technology for parents to use, the LENA System was complex for our scientists to develop. The LENA Digital Language Processor captures every utterance between parent, or other caregiver, and child. Then the software uses advanced algorithms and statistical models of adult speech and child vocalizations to analyze the language environment.

No one had ever attempted to automatically count and report on words spoken to a child and conversational turns in the highly variable and messy (from a speech recognition standpoint) home environment. A leading speech recognition expert laughed out loud when told what Infoture was trying to do . . .

LENA Software Development

To create the LENA software, Infoture scientists constructed algorithms and statistical models for adult speech and child vocalizations utilizing over 18,000 hours of recordings from 314 families. The recordings were repeatedly fed into a specially designed super computer with 148 parallel processors and 27,300 gigabytes of storage.

LENA filters out far field speech and estimates the number of words spoken by any adult — mother, father, or other caregiver — near the child.

LENA uses similar rules to Hart and Risley’s to measure conversational turns. A conversational turn is considered to have occurred when a child vocalizes and an adult responds, or an adult speaks and a child responds. Each time that happens, one turn is counted.

One child vocalization is counted when a child’s speech sound of any length is surrounded by at least 300 milliseconds of silence.

LENA also filters out the majority of non-speech sounds a child makes. Such sounds include vegetative sounds — those that have to do with respiration or digestion — as well as cries, screams, and whining sounds.

The LENA Language Environment software is particularly unique in that our engineers adapted cutting-edge speech recognition software to work in unstructured environments. Doing so enables LENA to eliminate child crying and vegetative sounds, as well as voices from a radio or television.

The LENA Developmental Snapshot

As part of the LENA System, Infoture developed the LENA Developmental Snapshot (LDS) comprising a 52-question parent survey regarding expressive and receptive language skills, and the resulting information about a child’s developmental age from two months to 36 months. Infoture investigated the accuracy of the LDS by comparing its estimated developmental age with the developmental age estimates of various standardized assessments. The LDS is highly correlated with recognized standardized assessments of language development (Pearson’s r = .93, p < .001).