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4/27/2009 The Power of Talk: The Impact of Adult Talk, Conversational Turns, & TV during the Critical Years (0-4) of Child Development Jill Gilkerson, Ph.D., & Jeffrey A. Richards, M.A. | |
| Note: This article will be peer-reviewed for ASHA CEUs. If you are interested in receiving ASHA CEUs, be sure to check back. Foreword Written by Todd Risley, Professor Emeritus of Psychology, University of Alaska Senior Scientist, Schiefelbusch Institute for Life Span Studies, University of Kansas, December 2006 In 1995, Betty Hart and I released the findings of a longitudinal research study that we had conducted for over a decade. Our book, Meaningful Differences in the Everyday Experience of Young American Children (Hart & Risely, 1995) described how we learned that the most important ingredient in the recipe for a child’s future academic success is the sheer volume of talk that the child’s parents have with the child—from the child’s birth until age three. It was a study rooted in the history of the War on Poverty. We knew long before we conducted our study that children differed greatly in how fast they acquired language skills and subsequently developed academically. We wanted to know why. We discovered that race and ethnicity has no bearing on a child’s academic success. In fact, even disadvantages attributed to socioeconomic status can be overcome. What matters is this: The more parents talk with their child from birth to age three, the more likely their child will excel academically later in life. And that sets the stage for other successes in the child’s future. If a parent only talks a little bit, the conversation is only about business. “Stop that.” “Get down from there.” “Come here.” But when a parent advances the conversation beyond business, the topics automatically change. The words used in conversation change, too. And that makes all the difference later in the child’s intellectual life. As is the case with most academic studies, we encountered certain limitations. The first was that we observed and recorded our 42 participants for only one hour every month. Also, the youngest children in our study were about seven months old, so we could only speculate about language development for children younger than that. In 2006, Infoture developed LENA, which stands for Language ENvironment Analysis. This remarkable technology is unlike any other tool available—for parents or researchers. With LENA, Infoture recorded the conversations between 314 children and their parents for 12-hour periods once a month for six to 11 months. The average number of 12-hour recordings per child was five. The children’s ages ranged from 2 months old to 36 months old. By using LENA, Infoture verified what Betty Hart and I had uncovered—that children who hear more words from birth to age three have more sophisticated language skills than children who don’t hear as many words. In other words, talk is the greatest tool parents can use to develop their child’s intellectual skills. Infoture also gained insights into the patterns of talk between parents and their children, when during the day that talk occurs more often and when talk occurs less. Of course, it is critical that parents know they are talking enough with their children. And that’s where LENA comes in. LENA makes it possible for parents to know exactly how much they talk with their child. It was professionally satisfying and exciting, as you might imagine, generating a study that educators, speech professionals, pediatricians, government officials, and parents have come to find important. And it’s equally satisfying and exciting to see our study confirmed—and new findings unveiled—with the use of a revolutionary new tool such as LENA. Overview The Power of Talk provides a sample of what has been learned so far from mining the data collected using the Language ENvironment Analysis (LENA) system. It describes the development of LENA and a natural language corpus on child and adult speech, the largest of its type in the world. This is the second edition of The Power of Talk; the first was published in January, 2007. Numerical results have changed since the first edition due to improvements in the software processing algorithms. More detailed data, figures, and tables regarding this report can be found at the Infoture website: www.LENAbaby.com One objective Infoture has had from the beginning, both in the development of the LENA system and in the collection of the data on child language development, was to confirm and extend the results of the breakthrough study by Betty Hart, Ph.D., and Todd Risley, Ph.D. Hart and Risley asked why some children do better academically than others. They determined that a child’s intellectual success later in life is directly related to the amount of talk the child hears from birth to age three. Research conducted by Infoture using LENA has indeed confirmed many of their important findings. Key findings to date include:
Meaningful Differences in the Everyday Experience of Young American Children describes the findings of a groundbreaking longitudinal study of parent-child talk in families in Kansas conducted over nearly a full decade by researchers Betty Hart, Ph.D., and Todd R. Risley, Ph.D. Over a three-year period, a team of researchers recorded one full hour of talk each month, including every word spoken at home between parents and children during that hour, for 42 families with children from 7 months to 36 months of age. They and their team observed and recorded parent-child talk during the late afternoon or early evening, a time when there is typically more conversation in the home. The team then spent an additional six years typing, coding, and analyzing some 30,000 pages of transcripts. Hart and Risley categorized participants based on socioeconomic status. Their sample comprised:
Follow-up studies by Hart and Risley of those same children at age nine showed that there was a very tight link between the academic success of a child and the number of words the child’s parents spoke to the child to age three. Hart and Risley’s findings include:
This finding is particularly notable because the child’s rate of vocabulary growth, vocabulary use, and IQ score was more strongly related to the number of words a parent said per hour than any other variable including parents’ education or socioeconomic status. Hart and Risley found that the amount of parent talk accounted for a significant portion of the verbal and intellectual accomplishments of the children in their study. In fact, according to Hart and Risley, the measure of accomplishments at age three predicted measures of language skills at ages nine and ten. Thus, the importance of the first three years of a child’s experience cannot be underestimated. The Language ENvironment Analysis System (LENA) LENA is the world’s first automatic natural language environment analysis system for infants and toddlers. The development of LENA was inspired by the work of Hart & Risely (1995). Infoture, Inc., the company that developed LENA, was founded on the belief that technology is best used to enhance the parent and child bond rather than become a substitute for it. It is the close daily interaction between parents and children that help children reach their full potentials. Infoture employs a world-class team of engineers, research academicians, linguists, and speech-language pathologists (SLPs) who have spent over four years and millions of dollars researching and developing LENA. In the time since the initial LENA development, Infoture has collected over 65,000 hours of audio recordings in the natural home environment. This database forms the basis for the analyses reported here, and it will be available for researchers worldwide to draw from to facilitate independent academic studies. The LENA system includes:
The LENA DLP captures every utterance between parent, or other caregiver, and child. Then the software uses advanced algorithms and statistical modeling to analyze the conversations and estimate three primary language-related measures: Adult Word Count (AWC; the number of adult words spoken); Conversational Turns (CT; adult-child alternations per day); and Child Vocalization frequency (CV; the number of words, babbles, and “protophones” or prespeech communicative sounds produced by the child). The accuracy of the LENA system was assessed using 70 one-hour test files from 70 different families (children 2 months to 36 months; 2 children per month of age). For Adult Word Count, LENA had a mean per-hour error rate of 2 percent compared to human transcribers. Accuracy for individual families may be better or worse due to variable sources of noise in the environment and confusion between non-speech noises and adult-child talk. Higher potential error rates are mitigated by the fact that, over time, errors tend to cancel out because relative values and relative change in the number of adult words and conversational turns are more important than absolute values. LENA is unique in that Infoture’s engineers adapted it to work in unstructured environments. Doing so enables LENA to discern between clear and unclear or faint speech and to filter out other sounds, such as child cries and vegetative sounds, or voices from a radio or television. In their study, Hart and Risley recorded one hour of conversation during a specific day every month—typically during the late afternoon or early evening. They counted the adult words and child vocalizations in that hour, and then extrapolated those findings across 14 waking hours to estimate the total number of adult words that their participants experienced. As a result, Hart and Risley estimated that children with advanced language skills would have heard more than 33 million words in the first three years of life, or about 30,000 words every day. Using LENA to record an entire 12-hour day of language experience with 329 participants enabled Infoture to accurately estimate the number of adult words that children in a highly enriched language environment hear in the first three years of life: almost 22 million words, or about 20,000 words every day. With LENA we could see for the first time the pattern of talk during the entire day, revealing that talk peaks during the late afternoon and early evening (something that Hart and Risley could not have known). Considering the fact that Hart and Risley extrapolated their estimate of 33 million words based on one hour of recording at peak talk hours, the LENA estimate based on 12-hour days and the Hart and Risley estimate based on 14-hour days are strikingly similar. Development of the LENA Software To create the LENA software, Infoture scientists constructed algorithms and mathematical models utilizing over 18,000 hours of recordings from 329 families. The recordings were repeatedly fed into a specially designed super computer with 148 parallel processors and 27,300 gigabytes of storage. The models included these parameters:
Table 1  Click Here to View Larger Version of Table 1 (PDF) The Infoture Natural Language Study Phase I There were 329 participants in Phase I of the Infoture Natural Language study. Participants recorded for at least 12 consecutive hours one day each month for six months from January through June, 2006. The children in Phase I were between 2 months and 48 months of age, and there were approximately 8 children in each age-month interval through age 36 months. During each month of Phase I Infoture added more 2-month-old children and continued to collect data from the children who had aged beyond 36 months. The sample was recruited from the Denver, CO metropolitan area through newspaper ads and direct mail solicitations. Over 2,000 people expressed interest in participating, and Infoture eventually narrowed the group to match United States Census figures with respect to the attained education level of participants’ mothers. Phase II Eighty Phase I participants, chosen to provide a representative sample with respect to children’s overall language ability and mothers’ attained education, were selected to participate in an extended longitudinal study (Phase II) from July 2006 through February 2009 and continue to record monthly. Results presented are based on over 32,000 hours of data from 2,682 recordings collected during Phases I and II through December 2007 from participant children ages 2 months through 48 months. Adult Words, Conversational Turns, & Child Vocalizations An important goal of the Infoture Natural Language Study has been the generation of the first normative percentile estimates for Adult Word Count, Conversational Turns, and Child Vocalizations (based on 12-hour days). Table 2 shows representative values for these measures for selected percentiles. Table 2  Click Here to View Larger Version of Table 2 (PDF) One of the most interesting details regarding adult speech that can be seen in this normative table is the degree of variation in amount of talk. Parents at the 90th percentile say over 1.5 times more words than parents at the 50th percentile and nearly 3.5 times more than parents at the 10th percentile. They engage in more conversational turns as well, at similar rates. Comparing Hart & Risley Estimates with LENA Estimates The LENA daily adult word count estimates are somewhat lower than those projected by Hart and Risley. The estimated mean word count for Hart and Risley’s professional class parents was 30,137 words per day, and the LENA 90th percentile is 20,824 words per day. Why are these counts different? The difference between Hart and Risley’s counts and the LENA counts can be attributed to data collection procedures. The participants in Hart and Risley’s study did not record all day—they recorded for one hour, and that hour was extrapolated to a 14-hour day. Importantly, Hart and Risley’s participants recorded in the afternoon and evening. As it turns out, the late afternoon and evening are peak talk times, something that Hart and Risley could not have known without LENA. Participants in the Infoture study recorded once a month for an entire 12-hour day; there was no extrapolation. The combined effect of these procedural differences means the LENA daily and hourly counts are approximately 30 percent lower than Hart and Risley’s estimates. This is actually good news. It means that each word a parent speaks to their child is 30 percent more powerful than what Hart and Risley estimated in 1995. The LENA Automatic Vocalization Assessment (AVA) The assessment of language development in young children poses numerous challenges that stem in part from the difficulty of collecting a sufficient quantity of representative language data. Speech-language professionals (SLPs)employ a variety of instruments to evaluate a child’s language development. These standard assessments incorporate both parent report and clinical observation components to varying degrees, are typically administered by a professional in a clinical setting, and can require from 30-90 minutes to complete and score. Consequently, the reliability and validity of these instruments can be affected by such factors as an unfamiliar clinical setting, heavy reliance on parent input, and limited observation time. Infoture’s goal for the automatic vocalization assessment (AVA) is to provide parents and professionals with an automated tool that can be used to screen children for language delay and to generate an objective expressive language development estimate as part of an overall evaluation, diagnostic, and treatment process. In particular, AVA is intended to minimize the effects of confounds inherent to evaluation in a clinical setting by collecting language data in the natural home environment over an entire day in as unobtrusive a manner as possible. AVA software uses automatic speech recognition technology to categorize and quantify the sounds present in a child’s vocalizations recorded using the LENA system. This quantitative acoustic information is analyzed statistically to generate information about the child’s expressive language development, which is reported as the AVA standard score, developmental age estimates, and an estimated mean length of utterance (EMLU). AVA Reliability Test-retest reliability for AVA is shown in Table 3, which details comparisons between AVA scores from recordings two months apart for participants ages 2-48 months. For reference, test-retest reliability values for PLS-4 and REEL-3 expressive language scores from administrations two months apart during the Infoture Natural Language Study are shown. As can be seen in the Correlation columns, AVA test-retest reliability is similar to that of the standard assessments. AVA scores from audio recordings collected one month apart correlated similarly well (r=.76, p<.01). The Mean Difference columns show that on average there were no significant differences between AVA scores from recordings made two months apart. Developmental age estimates were highly correlated (r=.99, p<.01). Estimates of ages one month apart, as would be expected, differed on average by approximately one month (M=1.1, SD=1.7). Table 3  Click Here to View Larger Version of Table 3 (PDF) AVA Validity The validity of AVA estimates was examined using a subset of 155 participants with six months of consecutive recordings by correlating AVA to an averaged SLP-assessed PLS-4/REEL-3 expressive language score. AVA standard scores were examined in two ways: first as single monthly scores, and then by averaging AVA scores from multiple recordings to produce a single estimate per child. Individual AVA scores for each month correlated well with the SLP-based score (r = 0.69 – 0.76, all p<.01). Averaged AVA scores from three successive months (1,2,3; 2,3,4; etc.) correlated as well or better (r = 0.77 – 0.80, all p<.01), and the average of AVA scores from every other month demonstrated ever stronger correlations (months 1,3,5: r = 0.88; months 2,4,6: r = 0.86, both p<.01). The validity of AVA developmental age estimates was tested by comparing them with chronological age and with PLS-4/REEL-3 expressive language estimates assessed within six weeks of the recording from which the AVA estimate was derived. AVA developmental age correlated well with chronological age (r = 0.97, p<.01) and with age estimates from the criterion measures (r= 0.93, p<.01). Alternately, the validity of the AVA estimate can be assessed by the accuracy with which it identifies children with potential expressive language delay. AVA scores from all available recordings were averaged to produce a single composite AVA score per child. Using a threshold score of 77.5 (i.e., 1.5 standard deviations below the mean) AVA correctly identified 11/19 = 58% of participants similarly identified as having a potential delay by the criterion measures. Eight (42%) of the SLP-identified children with possible delay have below average AVA estimates but do not meet the threshold criteria. The false positive rate is low; 3/317 = 1% of typically developing children in the sample fall below the AVA threshold, suggesting a possible expressive language delay. Standards Assessments Validate LENA Measures The Infoture Natural Language Study supports the conclusions that Hart and Risley (1995) drew from their study. Children’s scores on language and cognitive assessments are related to the amount of adult talk in their environment and the number of conversational turns they engage in with the parent. The Importance of Talk Infoture retained certified speech-language pathologists (SLPs) who assessed the language skills of participants during independent observation sessions. These measures then were correlated to Adult Word Count (AWC), Conversational Turns (CT), Child Vocalizations (CV), and AVA. As shown in Table 4, LENA measures correlated significantly with standard measures of language, confirming the importance of talk as reported in Hart and Risley’s research. Table 4  Click Here to View Larger Version of Table 4 (PDF) LENA Measures of Expressive Language Ability In addition to the data from the 329 typically developing children collected during the Infoture Natural Language Study, Infoture collected recording data using LENA from a sample of 31 children diagnosed with a language delay. The two samples were combined and split into decile groups based on each child’s average PLS-4 and/or REEL-3 expressive language score as assessed by a certified SLP. As expected, compared to the children in the upper deciles children in the lower deciles are exposed to less adult talk, engage in fewer conversational turns, vocalize less frequently, and have lower expressive language skills as assessed by AVA. Exploring the Home Language Time of Day Most talk between parents and children aged 2 months to 48 months typically occurred at the end of the day. The amount of talk throughout the morning was relatively flat. The biggest surprise from the timeline analysis was that there was not much talk in the early afternoon, presumably because children were eating or napping, and then rose until dinnertime. Television Studies have suggested that overexposure to television has a detrimental impact on young children’s language development (Christakis & Zimmerman, 2006). Data from the Infoture Natural Language Study provide support for this claim. This negative association with TV can also be seen for LENA measures. For example, in a sample of 165 2-year-olds, average detected TV time was negatively correlated with Adult Word Count (r=-.34, p<.01), with Conversational Turns (r=-.45, p<.01), with Child Vocalizations (r=-.41, p<.01), and with the child’s AVA expressive language score (r=-.29, p<.01). Researchers who are experts on the effect of television on child development, Frederick J. Zimmerman, Ph.D., and Dimitri A, Christakis, M.D., M.P.H. conducted independent analyses of the impact of television time on parent-child interactions using data from the Infoture Natural Language Study. They confirmed the negative impact of TV, importantly discovering that adult-child conversations (i.e., conversational turns) are a crucial aspect of a child’s language learning environment, more powerful than the quantity of adult words. In addition, they showed that at least one measurable effect television viewing may have is to reduce the number of such parent-child interactions. The Effect of Parent Talk Infoture asked study participants to rate the amount they talked to their children; 239 parents responded. Virtually all parents—99 percent—thought they talked an average amount (3 on a 5-point scale) or an above-average amount (4 or 5 on a 5-point scale). In fact, 74 percent of the parents thought they talked “more than average” (4 on a 5-point scale) or “much more than average” (5 on a 5-point scale). Of these parents who thought they talked more than average or much more than average, 40 percent were actually below the 50th percentile for adult word count. Only 20 percent of those who thought they talked much more than average were in the 80th percentile or higher. Children with Advanced Language Skills Have Parents Who Talk More Infoture confirmed that parents of advanced children—children who scored consistently between the 90th and 99th percentile on independent standard language assessments—talked significantly more to their children than parents of less advanced children. (Children’s language skills group designation was assigned based on the greater of each child’s average PLS-4 or REEL-3 overall language ability scores.) The parents of advanced children also engaged in significantly more conversational turns with their children. (Conversational turns for advanced versus non-advanced children were compared after first standardizing values by age. Displayed values reflect turn counts using each child’s average age.) Table 5 displays estimated mean values for these two groups. Table 5  Click Here to View Larger Version of Table 5 (PDF) The difference in the mean number of adult words spoken to advanced children compared to all other children is 2,295 words. In a 12-hour day, that is a difference of 191 words per hour. The mean difference in conversational turns between advanced children and their parents compared to all other children is 214 turns in a 12-hour day, or almost 18 additional turn-taking events an hour. Talkative Parents Have Talkative Children Confirming results from Hart and Risley’s research, the Infoture Natural Language Study found that as children of talkative parents grow older, they vocalize more frequently than children of taciturn parents. Whether parents were taciturn or talkative, the study showed that children had similar vocalization levels at an early age. With time and as the language environment started to have an effect, children’s vocalization rates grow significantly different, emphasizing the important role parents may play as language teachers for their children. Overall, children of talkative parents had average vocalization counts near the 67th percentile, whereas children of taciturn parents averaged below the 36th percentile (t(326)= 5.33, p<.01 Early Parent Talk Predicts Later Language Ability Infoture examined the power of adult talk during the first six months to predict later language ability in a sample of 27 children from the Phase II longitudinal sample. Average adult word counts from recordings completed when each child was between 2 months to 6 months of age were compared to average PLS-4 Total Language standard scores from evaluations completed on average at 24 months of age (range 18 months to 32 months). The more adult talk children were exposed to in the first six months, the higher their language ability scores were a year or more later (r=0.59, p<.01). A similar pattern was observed for conversational turns (r=0.51, p<.01). These results reinforce the importance of adult talk during the first few months to a child’s language development. Effect of Attained Education The variation in talk among college-educated parents was substantial. The average daily adult word count for professional parents—parents who earned at least a bachelor’s degree—was significantly higher (Mean=14,926) than the average daily adult word count (Mean=12,024) for other parents (t(327)=5.53, p<.01). However, there was substantial variation in adult word count within all groups. In fact, the upper 50 percent of parents who did not complete high school had a significantly higher average daily word count (Mean=14,245) than the lower 50 percent of parents who graduated from college (Mean=11,802; t(71) = 4.55, p< .01). Effect of Child Gender Infoture also looked at the differences between genders: Is there a difference between the amount of language input that girls receive from their parents compared to boys? It is often suggested that girls are generally more advanced than boys in the early school years. As Hart and Risley learned and Infoture confirmed, there are distinct academic advantages for children whose parents talk more to them. Do girls hear more words in the crucial development years? As can be seen in Table 6, there is evidence that girls do hear more words. Mothers tended to talk with their daughters more than with their sons. Up through age 30 months, mothers talked with their daughters nearly 9 percent more than mothers talked with their sons. Table 6  Click Here to View Larger Version of Table 6 (PDF) Fathers spoke substantially fewer words to their children than mothers did. Mothers spoke an average of 6,447 more words per day to their children, a difference that was more pronounced with daughters than with sons. Mothers contributed approximately 75 percent of the total adult words spoken, compared with the fathers’ 25 percent. (Although the LENA software does distinguish male from female word counts, these measurements are combined and reported as one aggregate number [Adult Word Count]. Adult male and female word counts can be obtained using the LENA Advanced Data Extractor [ADEX]). Effect of Birth Order Average daily adult word counts were somewhat higher for firstborn compared to latter-born children, whether or not the child had siblings. Overall, firstborn children were exposed to an average of 1,338 more words per day (t(327)=2.81, p<.01). There were interesting gender effects as well, both for the parents and for the children. Both male and female adults spoke significantly more to their firstborn boys than their latter-born boys, but spoke similarly to their girls regardless of birth order. Parents Can Change Their Behaviors One of the most important findings of the Infoture Natural Language Study is the high degree of variability in adult words and conversational turns between families and within families. But there weren’t only differences between families; families themselves differed from day-to-day. One method to characterize within-family variation for adult talk is to calculate the coefficient of variation based on the ratio of the variability in word counts to the average word count. In our normative sample, the coefficient of variation is 52.5 percent, meaning that any given day the typical family in our sample could vary in their total adult talk by over 50 percent of the average amount. That is, they might speak as little as 6,000 words or as many as 19,000 words on any particular day. Families are similarly variable when it comes to conversational turns. For a typical family with a 24 month-old, the coefficient of variation is 53 percent, with an average of 520 turns per day. So for this family, turn counts could range from as few as 250 to as many as 800 on any given day. Thus, day-to-day, both the amount of adult words a child hears and the number of conversational turns a child engages in varies substantially in the average family. Both the high within family and between family variation in the child language environment demonstrate that there is an opportunity for parents using LENA to improve significantly. Many parents on some days are already providing outstanding language environments for their children. Receiving feedback using the LENA software could help parents consistently provide more high word count and fewer low word count days and engage in more conversational turns, which in turn could help to improve their child’s cumulative language experience and accelerate their overall language development. Infoture provided LENA systems to 102 families in the US and UK and asked them to record weekly and to try to improve the amount they talked to their children. Parents who started out at or below the 20th percentile with respect to adult talk were able to increase their daily counts substantially using the feedback provided by the LENA software. Parents who started out at average levels were able to increase their counts as well. It is worth noting that both groups experience initial gains followed by slight declines, illustrating that behavioral change needs both feedback and reinforcement. Monolingual Spanish-Speaking Families Infoture collected monthly recording data over a 6-month period from a sample of 20 children 2 months to 34 months of age from monolingual Spanish-speaking families. Despite the small sample size relative to the normative sample, the pattern of adult talk over the course of a day was quite similar. Talk time is relatively high in the morning hours, drops toward lunch and nap times, then rises again. Again, despite the much smaller sample size, it is evident that the increase in counts for the college-educated families holds for both samples. There were no differences among the first three education groups, but the AWC for the most educated group is significantly higher than that for the other three groups. Conclusion The original study conducted by Hart and Risley—recording one hour of conversation between parents and young children in 42 homes each month for three years—was truly groundbreaking in that it led educators, government officials, teachers, linguists, and parents to rethink language development for children from birth to three years of age. Hart and Risley learned there was a direct correlation between adult words and a child’s IQ, adult words and a child’s academic success, and adult words and a child’s vocabulary learning trajectory. They also learned that families in the high socioeconomic status category talk more than families in other categories, but that the amount of talk between families varies tremendously—even among families in the high socioeconomic status category. The Infoture Natural Language Study, which used LENA to record conversations between parents and children in 329 homes over a 12-hour day for six months or more, was equally groundbreaking. Infoture confirmed the key finding of the Hart and Risley study—the best thing parents can do for their children is talk with them. Consistent with Hart and Risley’s research, the children most advanced with respect to language development had parents who spoke significantly more than parents of less advanced children. The LENA technology allowed Infoture to build on Hart and Risley’s seminal work, creating the first-ever percentile norms for daily adult word counts, conversational turns, and child vocalizations. Additional interesting findings from the Infoture Natural Language Study reflect the impact of gender and birth order on adult talk. Children heard more talk from their mothers than their fathers, and mothers talked more to their daughters than to their sons. Analyses also showed that both parents talked more to firstborn children, particularly boys, than to latter-born children. Not surprisingly, children of talkative parents were equally talkative, and children of taciturn parents were just as taciturn. This finding reflects the important role parents play in their children’s language development. Parents tend to overestimate the amount they talk to their children, and they can be highly variable from day-to-day. However, given the opportunity to receive feedback on how much they are talking, parents are able to increase that amount consistently. The LENA system permits a detailed look into the audio environment of the child. For example, the ability to track adult words on an hourly basis enabled Infoture to learn that most talk between parents and their children occurred in the late afternoon and early evening. Examination of television detected in the home revealed that the more television that was detected, the lower a child’s language abilities were. Moving beyond the Infoture Natural Language Study, the LENA system has been utilized to study the language environment of children from other populations. This research has found, for example, that monolingual Spanish-speaking families demonstrated similar patterns of talk to English-speaking families, and that parents of children with autism talked less the more severe their children’s symptoms were. Although many questions remain and there is much more research to be done, it is more and more clear that for the parents who want to give their child the best chance of succeeding academically, one key is to talk to and with their child as much as possible. References Accardo, P.J., & Capute, A.J. (2005). The Capute Scales: Cognitive Adaptive Test/Clinical Linguistic and Auditory Milestone Scale (CAT/CLAMS). Baltimore: Brookes. Bzoch, K.R., League, R., & Brown, V.L. (2003). Receptive-Expressive Emergent Language Test (3rd ed.; REEL-3). Austin: Pro-Ed. Christakis, D.A., & Zimmerman, F.J. (2006). The elephant in the living room: Make television work for your kids. New York: Rodale. Hart, B., & Risley, T.R. (1995). Meaningful differences in the everyday experience of young American children. Baltimore: Brookes. Ireton, H. (1992). Child Development Inventory (CDI). Minneapolis, MN: Behavior Science Systems. Zimmerman, I.L., Steiner, V.G., & Pond, R.E. (2002). Preschool Language Scale, (4th ed.; PLS-4). San Antonio: The Psychological Corporation. | |