|
The clunky, gargantuan tape recorders that speech-language pathologists have used for decades to collect data are officially obsolete. A small tool that is not much larger than a flash drive can record hours of uninterrupted speech in a child's natural language environment. The LENA (Language Environment Analysis) device tracks language development, including how many words children use every day and their interactions with parents and caregivers.
The device was inspired by the work of researchers Betty Hart, PhD, and Todd Risley, PhD, who used their own tape recorders to create an expansive database that is regarded as a milestone in the field of speech-language pathology. They recorded an hour of speech in 42 homes once a month over the course of two-and-a-half years and spent nearly a decade analyzing the thousands of hours of accumulated data. Their work led to the discovery that quality talk between parents and children is related directly to higher IQs and larger vocabularies.1
The LENA project has brought together professionals in speech-language pathology, speech and language science, and electrical engineering. Judy Montgomery, PhD, CCC-SLP, a professor at Chapman University, College of Educational Studies, in Orange, CA, became involved in the project when she was working on the Hart-Risley data.
"They focused on what a tape recorder could get sitting in the middle of the kitchen table every day from 5:00 to 6:00," said Dr. Montgomery, a member of the scientific advisory board for the LENA Foundation (www.lenafoundation.org). "Drop it off, tell the family to pretend it isn't there, go on talking, and then pick it up an hour later.' In a way it was such a simple thing, and other times it was such a profound thing."
Her interest in collecting information about young children's vocabulary drew her to the LENA project. "Words are the glue," she told ADVANCE. "They hold together our ideas and our ability to share those ideas with others. If people don't have a good command of vocabulary, they get very frustrated."
The mere presence of the device subtly changes the way adults behave, she said. "They think, 'Gotta talk!' I had no way of doing that before. I would tell parents, 'Talk to your child more,' and they would say, 'You told us that, but could we have a home program?'"
The LENA system now serves that function, picking up every word spoken in the home. The freedom it offers is one of its biggest benefits, Dr. Montgomery said. Parents are not required to do anything special, like buy a game, sit their child down, or say words in a certain way. They just need to talk more.
Drs. Hart and Risley originally assumed that the hour of data they collected each day represented the level of interaction in the home for the whole day. Based on that assumption, families would have used approximately 30,000 words daily. However, their recordings took place around dinner time, when people are more active.
Using the LENA device, researchers now estimate the daily word count to be between 17,000 and 20,000. On any given day there are periods of downtime when talking is rare. "Sometimes everybody just needs a little rest," said Dr. Montgomery. "We don't chat to babies all day long."
Parents who are quieter by nature do not have to feel inclined to become "talking machines," she said, but to at least make sure their child is included in conversation whenever possible."
The use of LENA now has expanded to families of 4-year-olds, allowing researchers to track children through the preschool experience. Currently, Dr. Montgomery and her doctoral students are examining children who have been identified as having developmental disabilities, including cerebral palsy, hearing loss and autism. "The family changes in terms of how much talking they do to that child. They lower their expectations. They tell me they don't, but they do," she said. They have to "keep talking, keep reading, and keep recording."
When gathering data, researchers ask parents to use the device five days a week for three weeks. Typically, the data will reveal that the child begins to respond more when spoken to, even after the relatively short time span of three weeks. They'll also notice that the "communication dance" between child and parent becomes livelier.
"That's what Todd Risley talked about for so long, this communication dance: 'You talk, I talk, you talk, I talk.' Typical learners go, 'Wow, this is how we play the talk game.' Kids with developmental disabilities don't always do that. Therefore, parents don't do it for as long or as much," said Dr. Montgomery.
She would like to see what the team can do in the future to bring therapy into the child's natural environment. Overall, though, she sees LENA becoming a progress monitoring tool. "At any point in time, you can give it a try," she said. "Just turn on the device and go on with the usual things you do. Two weeks later, try it again. See how you do on a typical day. I see it being used that way, which is pretty exciting."
Obtaining an accurate language assessment of a young child can be difficult, and getting language samples can be next to impossible. Data collection often is a hit-or-miss situation, and observation isn't always effective, especially if it's done in an artificial setting. Invariably, parents or caregivers offer excuses, such as "this isn't a typical day" or "he has a cold." They may blame a child's poor performance on a long car ride. Typical 15-minute therapy sessions cannot possibly represent a child's normal, everyday life. With LENA, however, these problems are avoided because data are collected continuously in a child's natural environment.
Parents are excited when they return the device to Dr. Montgomery, and they often participate in the analysis. "Recently, I was talking with a parent and said, "Look at this day; this is crazy. What happened on this day?' She said, 'We went to the zoo. We brought three adults with us and talked all day. We were exhausted when we got home.' I said, 'Wow, what a great language day. Look what you did!'"
When measurement tools like LENA become available, professionals come up with a variety of ways to use them, she said. "Clinicians step in and say, 'I could use it this way. How come nobody's done this yet?' I say, 'Go do it.' This is definitely one of those breakthroughs in measurements. Nobody has had this technology before."
While technology can be off-putting to some speech-language pathologists if they do not understand how they will benefit from it, others embrace it. "They are tired of recording language samples and writing down words that they hear on a tape recorder," Dr. Montgomery noted. "They say, "Give me a device!'"
As a member of the scientific advisory board for the LENA Foundation, Kimbrough Oller, PhD, of the School of Audiology and Speech-Language Pathology at the University of Memphis, has participated in all of the changes the project has undergone in the last four years. "We're in the third or fourth generation of results that are based on the various processing schemes developed around the LENA device," said Dr. Oller, who specializes in infant vocal development. "A huge database has been collected-over 70,000 hours of recording."
The database suggests a range of applications for LENA, and the recorder and software provide a strong basis for research, he said. "For example, the database makes it possible to compare how children are developing on a variety of vocal measures across ages. It can be measured automatically so people don't have to sit down and listen to the many hours of recording that are involved." Recently, researchers ran an analysis on 6 million child utterances, which no one was able to do before.
LENA provides researchers with a large pool of data at their fingertips. "The most interesting things that are happening concern comparisons across groups of children," Dr. Oller said. "There is much going on in that realm. We think this approach will make it possible for useful comparisons between infants developing normally and those with disabilities."
LENA also has implications for developmental studies, interventional studies, and studies on the reliability of home-based child care services, said Charles Greenwood, PhD, director of the Juniper Gardens Children's Project, in Kansas City, KS, and a member of the LENA Foundation scientific advisory board.
One of the most exciting aspects of LENA is the group of people working on it, he said. "It has brought together a range of excellent but diverse scientists who have been collaborating in a very fascinating way around all the issues of the speech processing aspect. Like many developments in science, as soon as you can measure something very accurately and efficiently, many new areas of inquiry open up."
The development of the system is a big step forward in the area of speech recognition. "This is probably the most untapped area for analyzing children's babble," he noted. "Now we can get a sense of how much talk the child is hearing, which is very important."
The LENA system has the potential to influence intervention studies by speech-language pathologists, psychologists and behavioral psychologists, Dr. Greenwood believes. For example, if the rate of talk is low in families, what can professionals do to increase it substantially over a certain period of time, and how would that intervention benefit children?
One of the problems with interventions that take place in the home for children with language problems is that there is no way of knowing how well parents follow through on instructions from speech-language pathologists, he said. Many home interventions "are designed to engage the parent as part of the intervention. The parent is prompted to interact with the child in certain ways during the day. But when the visitor leaves, what's the fidelity of implementation of the intervention by the parents? LENA can show us that."
The LENA system is one of the biggest advancements in the field of children's language assessment, according to John Hansen, PhD, who has a background in both electrical engineering and speech and language science. "It's revolutionary," said Dr. Hansen, chair of the Department of Electrical Engineering at the University of Texas at Dallas. "Typically, speech-language pathologists work with children for 10 minutes to an hour, and they may not see them for a couple of weeks or a month. When you only get a snapshot, it's not enough to assess progress. It doesn't give you the opportunity to see what's happening in a naturalistic environment."
The development team is looking to take the system into the realm of autism, which Dr. Hansen believes will yield great benefits. His personal interest is seeing how the device can be used in multi-infant or multi-children scenarios, such as in day care settings or orphanages, where it is difficult to track the language exposure of each child.
"This device will do for child's speech-language pathology specialists and families what Apple has done for the entertainment field with the iPod," said Dr. Hansen. "It will give speech-language pathologists, language specialists and pediatricians the ability to step into the home environment and leverage the amount of time they can spend with a family, and allow parents to become more active participants in a child's overall language development."
Reference
- Hart, B., Risley, T. (1995). Meaningful Differences in the Everyday Experience of Young American Children. Baltimore, MD: Brookes Publishing.
For More Information
Jason Mosheim is a Senior Associate Editor at ADVANCE. He can be contacted at jmosheim@advanceweb.com.
|