Infant-Directed Speech Enhances Attention to Speech in Deaf Infants With Cochlear Implants

Listening Preference for Child-Directed Speech Versus Time-Reversed Speech in Moderate-Preterm Infants Compared to Full-Term Infants

PURPOSE

The purpose of the present study was to examine whether there is a listening preference for child-directed speech (CDS) over backward speech in moderate-preterm infants (MPIs).

METHOD

Eighteen MPIs of gestational age of 32.0 weeks (range: 32-34.06 weeks), chronological age of 8.09 months, and maturation age of 6.48 months served as the experimental group. The two control groups consisted of a total of 36 infants-20 full-term infants matched for chronological age and 16 full-term infants matched for maturation age. The infants were tested using the central fixation procedure and were presented with 16 trials of CDS and backward speech. A follow-up was conducted 5 years after the initial experiment using a developmental and a five-item parent questionnaire.

RESULTS

MPIs did not demonstrate a preference for CDS over backward speech, whereas both control groups demonstrated a listening preference for CDS over backward speech. MPIs showed a delayed use of first words and word combinations and lower scores on the five-item questionnaire compared to term infants. Twelve MPIs (67%) did not demonstrate a preference for CDS over backward speech. Four of them (33%) were later diagnosed with neurodevelopmental disorders.

CONCLUSIONS

The lack of preference for CDS over backward speech in the MPIs group suggests delayed developmental pattern of speech processing compared to full-term peers. Delays in neurological maturation as well as listening experience in an unregulated environment outside the uterus during a sensitive period of brain development may affect the recognition of phonological and prosodic patterns that support listening preference for speech over backward speech.

The everyday speech environments of preschoolers with and without cochlear implants

Children who receive cochlear implants develop spoken language on a protracted timescale. The home environment facilitates speech-language development, yet it is relatively unknown how the environment differs between children with cochlear implants and typical hearing. We matched eighteen preschoolers with implants (31-65 months) to two groups of children with typical hearing: by chronological age and hearing age. Each child completed a long-form, naturalistic audio recording of their home environment (appx. 16 hours/child; >730 hours of observation) to measure adult speech input, child vocal productivity, and caregiver-child interaction. Results showed that children with cochlear implants and typical hearing were exposed to and engaged in similar amounts of spoken language with caregivers. However, the home environment did not reflect developmental stages as closely for children with implants, or predict their speech outcomes as strongly. Home-based speech-language interventions should focus on the unique input-outcome relationships for this group of children with hearing loss.

Assessing parent interaction with deaf infants: A quantitative survey of UK professional practice

BACKGROUND

Between 90% and 95% of deaf children are born to hearing parents who often need support with how to adapt their communication. Parent-child interaction (PCI) is an important predictor of deaf children's future language development. It is therefore necessary for professionals to assess parents' strengths and needs to identify areas for intervention. Qualified teachers of the deaf (QToDs), speech and language therapists (SLTs), psychologists, and national deaf child and adolescent mental health (NDCAMHS) professionals regularly support families with deaf children. With no current evidence-based tool available to assist with the assessment of PCI in deafness, it is important to gather information on current professional practice as this may differ from known practices within research.

AIMS

To survey the practices of UK-based professionals in the assessment of PCI where the deaf infant is aged 0-3 years. Professionals were QToDs, SLTs, psychologists or psychiatrists and professionals working at NDCAMHS services.

METHODS & PROCEDURES

After a pilot phase, an 85-item survey was distributed electronically through a range of professional and social media networks. Survey items were based on a systematic review of PCI with deaf infants. Survey questions were focused on parent behaviours that were assessed, methods of assessment, goal planning and service provision. Analysis was conducted using descriptive and inferential statistics.

OUTCOMES & RESULTS

A total of 190 professionals from across the UK completed part 1 of the survey; this decreased to 148 in part 4. Respondents were primarily female, hearing, used spoken English and had 16 years or more experience. Results indicate that PCI is routinely assessed by a large proportion of professionals and there is a substantial overlap in which parent behaviours are assessed. Some parent behaviours are assessed that do not feature in the research. Methods of assessment are informal and predominantly consist of observation and note making, with professionals using their own skills and experience to analyse interaction. Goal setting practices were largely similar between professionals, with many jointly deciding goals with parents.

CONCLUSIONS & IMPLICATIONS

This survey highlights the range of parent behaviours assessed by UK professionals in PCI with deaf children aged 0-3. This survey provides valuable information about and for professionals who assess PCI and set intervention goals with parents. Information from research and professional practice is important to consider in the design of a future PCI assessment. Implications are included for future research in this area.

WHAT THIS PAPER ADDS

What is already known on this subject Parental involvement is one of the greatest predictors of deaf children's language outcomes. With many deaf children born to hearing parents, parents often need guidance with how to facilitate effective communication. A recent systematic review identified the range of parent behaviours and methods used to analyse PCI in international research studies, but little evidence or guidance exists on how professionals assess this phenomenon in practice. What this study adds This is the first survey to generate large, valuable practice-based evidence for the assessment of parents' communication behaviours as they interact with their deaf infants aged 0-3. The survey recruited a range of multidisciplinary professionals working on interaction within this field: SLTs, qualified teachers of the deaf, psychologists or psychiatrists, and professionals working within deaf child and adolescent mental health services. The study reports on which behaviours these professionals assess and how, and includes information on the goal setting behaviours of practitioners. Most respondents were highly experienced; the survey, therefore, reveals expert practice within the field. What are the potential or actual clinical implications of this work? We recommend the following practice: (1) incorporate a range of parent-based behaviours in PCI assessments, including establishing joint engagement and parental sensitivity, as well as communication-focused behaviours; (2) video record PCI assessments where possible to enable professionals and parents to watch and reflect together; (3) following assessment, set parent-focused goals in collaboration with families, ensuring parents' skills, particularly their strengths, are considered. All primary caregivers should be included in the process where possible; and (4) reassess PCI regularly (at least termly) to monitor and encourage families' progress. The timing of reviews should be discussed between parent and professional.

Effect of telepractice on pediatric cochlear implant users and provider vowel space: A preliminary report

Clear speaking styles are goal-oriented modifications in which talkers adapt acoustic-phonetic characteristics of speech to compensate for communication challenges. Do children with hearing loss and a clinical provider modify speech characteristics during telepractice to adjust for remote communication? The study examined the effect of telepractice (tele-) on vowel production in seven (mean age 4:11 years, SD 1:2 years) children with cochlear implants (CIs) and a provider. The first (F1) and second (F2) formant frequencies of /i/, /ɑ/, and /u/ vowels were measured in child and provider speech during one in-person and one tele-speech-language intervention, order counterbalanced. Child and provider vowel space areas (VSA) were calculated. The results demonstrated an increase in F2 formant frequency for /i/ vowel in child and provider speech and an increase in F1 formant frequency for /ɑ/ vowel in the provider speech during tele- compared to in-person intervention. An expansion of VSA was found in child and provider speech in tele- compared to in-person intervention. In children, the earlier age of CI activation was associated with larger VSA in both tele- and in-person intervention. The results suggest that the children and the provider adjust vowel articulation in response to remote communication during telepractice.

Effects of Segmental and Suprasegmental Speech Perception on Reading in Pediatric Cochlear Implant Recipients

PURPOSE

The aim of this study was to determine whether suprasegmental speech perception contributes unique variance in predictions of reading decoding and comprehension for prelingually deaf children using two devices, at least one of which is a cochlear implant (CI).

METHOD

A total of 104, 5- to 9-year-old CI recipients completed tests of segmental perception (e.g., word recognition in quiet and noise, recognition of vowels and consonants in quiet), suprasegmental perception (e.g., talker and stress discrimination, nonword stress repetition, and emotion identification), and nonverbal intelligence. Two years later, participants completed standardized tests of reading decoding and comprehension. Using regression analyses, the unique contribution of suprasegmental perception to reading skills was determined after controlling for demographic characteristics and segmental perception performance.

RESULTS

Standardized reading scores of the CI recipients increased with nonverbal intelligence for both decoding and comprehension. Female gender was associated with higher comprehension scores. After controlling for gender and nonverbal intelligence, segmental perception accounted for approximately 4% and 2% of the variance in decoding and comprehension, respectively. After controlling for nonverbal intelligence, gender, and segmental perception, suprasegmental perception accounted for an extra 4% and 7% unique variance in reading decoding and reading comprehension, respectively.

CONCLUSIONS

Suprasegmental perception operates independently from segmental perception to facilitate good reading outcomes for these children with CIs. Clinicians and educators should be mindful that early perceptual skills may have long-term benefits for literacy. Research on how to optimize suprasegmental perception, perhaps through hearing-device programming and/or training strategies, is needed.

Associations Between Parent Mental State Language and Child Inhibitory Control in Children Who Are Deaf or Hard of Hearing

PURPOSE

Children who are deaf or hard of hearing (D/HH) are at increased risk for neurocognitive delays, which can have cascading effects on development. Associations between neurocognition and the content of parental language-specifically the use of mental state vocabulary-have been observed in typically hearing (TH) children. This study investigated the role of parental use of mental state language (e.g., vocabulary related to thought processes, desires, and emotions) in explaining variability in neurocognition in children who are D/HH.

METHOD

Dyads of 62 TH and 69 D/HH children who wear hearing aids or cochlear implants (ages 3-8 years) and their primary parent were videorecorded during a 20-min play session. Specific mental state words used by parents were extracted. Child neurocognition (specifically, inhibitory control) was assessed using norm-referenced measures.

RESULTS

Parent use of mental state language predicted child inhibitory control differentially based on hearing status, with a significant relation in the D/HH but not the TH group. Mental state vocabulary related to cognition (e.g., "think," "know"), but not to desire (e.g., "want," "like") or emotion (e.g., "feel," "frustrated"), predicted child inhibitory control in the D/HH group. Finally, there was a significant relation between the use of first person, but not second or third person, mental state verbs (e.g., "I think") and child inhibitory control.

CONCLUSIONS

Parental use of cognitive mental state vocabulary models language around thought processes, and parents' use of first-person referents models "self-talk." Modeling of these linguistic forms is likely foundational for developing self-regulation. Children who are D/HH often experience reduced auditory access and/or language delays and thus rely on high-quality parental language input for longer periods of development than their TH peers. Continued support from interventionists is indicated to coach parents to be high-quality models of more abstract, decontextualized language, supporting complex language development and inhibitory control in children who are D/HH.

A Framework for Understanding the Relation Between Spoken Language Input and Outcomes for Children with Cochlear Implants

Spoken language outcomes after cochlear implantation are highly variable. Some variance can be attributed to individual characteristics. Research with typically hearing children suggests that the amount of language directed to children may also play a role. However, several moderating factors may complicate the association between language input and language outcomes in children with cochlear implants. In this article, I present a conceptual framework that posits that the association between total language input directed to children and language outcomes is moderated by factors that influence what is accessible, attended to, and coordinated with the child. The framework also posits that children with cochlear implants exhibit more variability on those moderating factors, which explains why the relation between language input and language outcomes may be more complex even if language input is more important for successful language outcomes in this population.

Language development in infants with hearing loss: Benefits of infant-directed speech

The majority of infants with permanent congenital hearing loss fall significantly behind their normal hearing peers in the development of receptive and expressive oral communication skills. Independent of any prosthetic intervention ("hardware") for infants with hearing loss, the social and linguistic environment ("software") can still be optimal or sub-optimal and so can exert significant positive or negative effects on speech and language acquisition, with far-reaching beneficial or adverse effects, respectively. This review focusses on the nature of the social and linguistic environment of infants with hearing loss, in particular others' speech to infants. The nature of this "infant-directed speech" and its effects on language development has been studied extensively in hearing infants but far less comprehensively in infants with hearing loss. Here, literature on the nature of infant-directed speech and its impact on the speech perception and language acquisition in infants with hearing loss is reviewed. The review brings together evidence on the little-studied effects of infant-directed speech on speech and language development in infants with hearing loss, and provides suggestions, over and above early screening and external treatment, for a natural intervention at the level of the carer-infant microcosm that may well optimize the early linguistic experiences and mitigate later adverse effects for infants born with hearing loss.

Variability in Quantity and Quality of Early Linguistic Experience in Children With Cochlear Implants: Evidence from Analysis of Natural Auditory Environments

OBJECTIVES

Understanding how quantity and quality of language input vary across children with cochlear implants (CIs) is important for explaining sources of large individual differences in language outcomes of this at-risk pediatric population. Studies have mostly focused either on intervention-related, device-related, and/or patient-related factors, or relied on data from parental reports and laboratory-based speech corpus to unravel factors explaining individual differences in language outcomes among children with CIs. However, little is known about the extent to which children with CIs differ in quantity and quality of language input they experience in their natural linguistic environments. To address this knowledge gap, the present study analyzed the quantity and quality of language input to early-implanted children (age of implantation <23 mo) during the first year after implantation.

DESIGN

Day-long Language ENvironment Analysis (LENA) recordings, derived from home environments of 14 early-implanted children, were analyzed to estimate numbers of words per day, type-token ratio (TTR), and mean length of utterance in morphemes (MLUm) in adults' speech. Properties of language input were analyzed across these three dimensions to examine how input in home environments varied across children with CIs in quantity, defined as number of words, and quality, defined as whether speech was child-directed or overheard.

RESULTS

Our per-day estimates demonstrated that children with CIs were highly variable in the number of total words (mean ± SD = 25,134 ± 9,267 words) and high-quality child-directed words (mean ± SD = 10,817 ± 7,187 words) they experienced in a day in their home environments during the first year after implantation. The results also showed that the patterns of variability across children in quantity and quality of language input changes depending on whether the speech was child-directed or overheard. Children also experienced highly different environments in terms of lexical diversity (as measured by TTR) and morphosyntactic complexity (as measured by MLUm) of language input. The results demonstrated that children with CIs varied substantially in the quantity and quality of language input experienced in their home environments. More importantly, individual children experienced highly variable amounts of high-quality, child-directed speech, which may drive variability in language outcomes across children with CIs.

CONCLUSIONS

Analyzing early language input in natural, linguistic environments of children with CIs showed that the quantity and quality of early linguistic input vary substantially across individual children with CIs. This substantial individual variability suggests that the quantity and quality of early linguistic input are potential sources of individual differences in outcomes of children with CIs and warrant further investigation to determine the effects of this variability on outcomes.

Interdisciplinary Approaches to the Study of Listening Effort in Young Children with Cochlear Implants

Very early bilateral implantation is thought to significantly reduce the attentional effort required to acquire spoken language, and consequently offer a profound improvement in quality of life. Despite the early intervention, however, auditory and communicative outcomes in children with cochlear implants remain poorer than in hearing children. The distorted auditory input via the cochlear implants requires more auditory attention resulting in increased listening effort and fatigue. Listening effort and fatigue may critically affect attention to speech, and in turn language processing, which may help to explain the variation in language and communication abilities. However, measuring attention to speech and listening effort is demanding in infants and very young children. Three objective techniques for measuring listening effort are presented in this paper that may address the challenges of testing very young and/or uncooperative children with cochlear implants: pupillometry, electroencephalography, and functional near-infrared spectroscopy. We review the studies of listening effort that used these techniques in paediatric populations with hearing loss, and discuss potential benefits of the systematic evaluation of listening effort in these populations.

Estimating the reduced benefit of infant-directed speech in cochlear implant-related speech processing

Caregivers modify their speech when talking to infants, a specific type of speech known as infant-directed speech (IDS). This speaking style facilitates language learning compared to adult-directed speech (ADS) in infants with normal hearing (NH). While infants with NH and those with cochlear implants (CIs) prefer listening to IDS over ADS, it is yet unknown how CI processing may affect the acoustic distinctiveness between ADS and IDS, as well as the degree of intelligibility of these. This study analyzed speech of seven female adult talkers to model the effects of simulated CI processing on (1) acoustic distinctiveness between ADS and IDS, (2) estimates of intelligibility of caregivers' speech in ADS and IDS, and (3) individual differences in caregivers' ADS-to-IDS modification and estimated speech intelligibility. Results suggest that CI processing is substantially detrimental to the acoustic distinctiveness between ADS and IDS, as well as to the intelligibility benefit derived from ADS-to-IDS modifications. Moreover, the observed variability across individual talkers in acoustic implementation of ADS-to-IDS modification and the estimated speech intelligibility was significantly reduced due to CI processing. The findings are discussed in the context of the link between IDS and language learning in infants with CIs.

Differential At-Risk Pediatric Outcomes of Parental Sensitivity Based on Hearing Status

Purpose The aim of this study was to investigate the role of parental sensitivity in language and neurocognitive outcomes in children who are deaf and/or hard of hearing (DHH). Method Sixty-two parent-child dyads of children with normal hearing (NH) and 64 of children who are DHH (3-8 years) completed parent and child measures of inhibitory control/executive functioning and child measures of sentence comprehension and vocabulary. The dyads also participated in a video-recorded, free-play interaction that was coded for parental sensitivity. Results There was no evidence of associations between parental sensitivity and inhibitory control or receptive language in children with NH. In contrast, parental sensitivity was related to children's inhibitory control and all language measures in children who are DHH. Moreover, inhibitory control significantly mediated the association between parental sensitivity and child language on the Clinical Evaluation of Language Fundamentals-Fifth Edition Following Directions subscale (6-8 years)/Clinical Evaluation of Language Fundamentals Preschool-Second Edition Concepts and Following Directions subscale (3-5 years). Follow-up analyses comparing subgroups of children who used hearing aids (n = 29) or cochlear implants (CIs; n = 35) revealed similar correlational trends, with the exception that parental sensitivity showed little relation to inhibitory control in the group of CI users. Conclusions Parental sensitivity is associated with at-risk language outcomes and disturbances in inhibitory control in young children who are DHH. Compared to children with NH, children who are DHH may be more sensitive to parental behaviors and their effects on emerging inhibitory control and spoken language. Specifically, inhibitory control, when scaffolded by positive parental behaviors, may be critically important for robust language development in children who are DHH.

Infants' Preference for Child-Directed Speech Over Time-Reversed Speech in On-Channel and Off-Channel Masking

Purpose This study aims to examine the development of auditory selective attention to speech in noise by examining the ability of infants to prefer child-directed speech (CDS) over time-reversed speech (TRS) presented in "on-channel" and "off-channel" noise. Method A total of 32 infants participated in the study. Sixteen typically developing infants were tested at 7 and 11 months of age using the central fixation procedure with CDS and TRS in two types of noise at +10 dB signal-to-noise ratio. One type of noise was an "on-channel" masker with a spectrum overlapping that of the CDS (energetic masking), and the second was an "off-channel" masker with frequencies that were outside the spectrum of the CDS (distractive masking). An additional group of sixteen 11-month-old infants were tested in quiet and served as controls for the "off-frequency" masker condition. Results Infants preferred CDS over TRS in both age groups, but this preference was more pronounced with "off-channel" masker regardless of age. Also, older infants demonstrated longer looking time for the target stimuli when presented with an "off-channel" masker compared to the "on-channel" masker. Looking time in quiet was similar to looking time in the "off-channel" condition, and looking time for CDS was longer in quiet compared to the "on-channel" condition. Conclusions These findings support the notion that (a) infants as young as 7 months of age are already showing preference for speech in noise, regardless of type of masker; (b) by 11 months of age, listening with the "off-channel" condition did not yield different results than in quiet. Thus, by 11 months of age, infants' cognitive-attentional abilities may be more developed.

Tailoring the Input to Children's Needs: The Use of Fine Lexical Tuning in Speech Directed to Normally Hearing Children and Children With Cochlear Implants

Purpose: The aim of the present study was to explore fine lexical tuning in Dutch infant-directed speech (IDS) addressed to congenitally deaf infants who received a cochlear implant (CI) early in life (<2 years of age) in comparison with children with normal hearing (NH). The longitudinal pattern of parents' utterance length in the initial stages of the child's lexical development was examined. Parents' utterances containing the words the children eventually acquired in the earliest developmental stages were selected and their MLU (Mean Length of Utterance) was measured.

Method: Transcriptions of monthly recordings of spontaneous interactions of 10 CI children and 30 NH children with their parents were analyzed. The children with CI were followed from the moment their device was switched on, and the NH children from the age of 6 months onwards. A total of 57,846 utterances of parents of CI children and 149,468 utterances of parents of NH children were analyzed.

Results: IDS addressed to children with NH and children with CI exhibits fine lexical tuning: parents adjust the MLU of the utterances that contain the words that children are on the verge of producing themselves. More specifically, the parents' mean length of those utterances decreased in relation to the point when the children began using the item. Consequently, the number of occurrences in isolation of the lexical item increased. The speech addressed to all the children exhibited this phenomenon, but it was significantly more strongly present in speech addressed to the children with CI.

Conclusions: The speech addressed to children with NH and CI is characterized by fine lexical tuning and a high incidence of single-word utterances in the period leading up to the children's first use of words in speech production. Notwithstanding striking commonalities, IDS addressed to children with a hearing impairment is markedly different, which suggests that parents take this specific character of the children into account.

Speech Perception and Language Outcomes for Infants Receiving Cochlear Implants Before or After 9 Months of Age: Use of Category-Based Aggregation of Data in an Unselected Pediatric Cohort

Purpose This retrospective study aimed to amass large data sets to enable statistical comparisons of communication outcomes for infants receiving cochlear implants (CIs) before 9 months of age compared to groups who received their first CI between 9 months and 3.5 years of age. Method Speech perception scores and experienced clinicians' observations were used to refine the Categories of Auditory Performance Index (CAPI), thus creating its revised version, namely, the CAPI-Revised (CAPI-R). Standardized and criterion-referenced language data were used to create the novel Categories of Linguistic Performance (CLIP). The association between CAPI-R and CLIP data at two time points post implant (at 2 years of device experience and at 5 years of age) was examined in a large unselected cohort stratified for age at first implant: before 9 months (Group 1), between 9 and 12 months (Group 2), between 13 and 18 months (Group 3), between 19 and 24 months (Group 4), between 25 and 30 months (Group 5), between 31 and 36 months (Group 6), and between 37 and 42 months (Group 7). Results CAPI-R medians were 5 at 2 years of device experience, and 6 at 5 years of age. At 2 years of device experience, there was no significant difference in CAPI-R medians for children who received their first CI before 9 months compared to all other age-at-implant groups. At 5 years of age, a significantly better CAPI-R median was demonstrated by Group 1 (CI before 9 months) compared to Groups 4, 5, 6, and 7. CLIP medians were 3 at 2 years of device experience, and at 5 years of age. At 2 years device experience, and at 5 years of age, the Group 1 CLIP medians were significantly better than later age-at-implant groups. Conclusion Median CAPI-R outcomes supported access to CIs before 18 months of age for speech perception, and median CLIP outcomes supported access to CIs before 9 months of age for optimum language development.

Individual Differences in Mothers' Spontaneous Infant-Directed Speech Predict Language Attainment in Children With Cochlear Implants

Purpose Differences across language environments of prelingually deaf children who receive cochlear implants (CIs) may affect language acquisition; yet, whether mothers show individual differences in how they modify infant-directed (ID) compared with adult-directed (AD) speech has seldom been studied. This study assessed individual differences in how mothers realized speech modifications in ID register and whether these predicted differences in language outcomes for children with CIs. Method Participants were 36 dyads of mothers and their children aged 0;8-2;5 (years;months) at the time of CI implantation. Mothers' spontaneous speech was recorded in a lab setting in ID or AD conditions before ~15 months postimplantation. Mothers' speech samples were characterized for acoustic-phonetic and lexical properties established as canonical indices of ID speech to typically hearing infants, such as vowel space area differences, fundamental frequency variability, and speech rate. Children with CIs completed longitudinal administrations of one or more standardized language assessment instruments at variable intervals from 6 months to 9.5 years postimplantation. Standardized scores on assessments administered longitudinally were used to calculate linear regressions, which gave rise to predicted language scores for children at 2 years postimplantation and language growth over 2-year intervals. Results Mothers showed individual differences in how they modified speech in ID versus AD registers. Crucially, these individual differences significantly predicted differences in estimated language outcomes at 2 years postimplantation in children with CIs. Maternal speech variation in lexical quantity and vowel space area differences across ID and AD registers most frequently predicted estimates of language attainment in children with CIs, whereas prosodic differences played a minor role. Conclusion Results support that caregiver language behaviors play a substantial role in explaining variability in language attainment in children receiving CIs. Supplemental Material https://doi.org/10.23641/asha.12560147.

A meta-analysis of the predictability of LENA™ automated measures for child language development

Early language environment plays a critical role in child language development. The Language ENvironment Analysis (LENA™) system allows researchers and clinicians to collect daylong recordings and obtain automated measures to characterize a child's language environment. This meta-analysis evaluates the predictability of LENA's automated measures for language skills in young children. We systematically searched reports for associations between LENA's automated measures, specifically, adult word count (AWC), conversational turn count (CTC), and child vocalization count (CVC), and language skills in children younger than 48 months. Using robust variance estimation, we calculated weighted mean effect sizes and conducted moderator analyses exploring the factors that might affect this relationship. The results revealed an overall medium effect size for the correlation between LENA's automated measures and language skills. This relationship was largely consistent regardless of child developmental status, publication status, language assessment modality and method, or the age at which the LENA recording was taken; however, the effect was weakly moderated by the gap between LENA recordings and language measures taken. Among the three measures, there were medium associations between CTC and CVC and language, whereas there was a small-to-medium association between AWC and language. These findings extend beyond validation work conducted by the LENA Research Foundation and suggest certain predictive strength of LENA's automated measures for child language. We discussed possible mechanisms underlying the observed associations, as well as the theoretical, methodological, and clinical implications of these findings.

Longitudinal Development of Executive Functioning and Spoken Language Skills in Preschool-Aged Children With Cochlear Implants

Purpose Auditory deprivation has downstream effects on the development of language and executive functioning (EF) in prelingually deaf children with cochlear implants (CIs), but little is known about the very early development of EF during preschool ages in children with CIs. This study investigated the longitudinal development of EF and spoken language skills in samples of children with normal hearing (NH; N = 40) or CIs (N = 41) during preschool ages. Method Participants were enrolled in the study between ages 3 and 6 years and evaluated annually up to the age of 7 years. Mixed-effects models were used to evaluate and predict growth of spoken language and EF skills over time. Results Children with CIs scored lower than NH peers on language measures but improved significantly over time. On performance-based neurocognitive measures of controlled attention, inhibition, and working memory, children with CIs scored more poorly than the sample of NH peers but comparable to norms, whereas on a parent report behavior checklist, children with CIs scored more poorly than both NH peers and norms on inhibition and working memory. Children with CIs had poorer EF than the sample of NH peers in most domains even after accounting for language effects, and language predicted only the verbal working memory domain of EF. In contrast, EF skills consistently predicted language skills at subsequent visits. Conclusions Findings demonstrate that, despite significant improvement over time, some domains of EF (particularly parent-reported EF) and language skills in children with CIs lag behind those of children with NH during preschool ages. Language delays do not fully explain differences in EF development between children with CIs and NH peers during preschool ages, but EF skills predict subsequent language development in children with CIs.

Lexical Repetition Properties of Caregiver Speech and Language Development in Children With Cochlear Implants

Purpose Early language input plays an important role in child language and cognitive development (e.g., Gilkerson et al., 2018; Hart & Risley, 1995). In this study, we examined the effects of child's hearing status on lexical repetition properties of speech produced by their caregivers with normal hearing (NH). In addition, we investigated the relationship between maternal lexical repetition properties and later language skills in English-learning infants with cochlear implants (CIs). Method In a free-play session, 17 mothers and their prelingually deaf infants who received CIs before 2 years of age (CI group) were recorded at two post-CI intervals: 3 and 6 months postactivation; 18 hearing experience-matched infants with NH and their mothers and 14 chronological age-matched infants with NH group and their mothers were matched to the CI group. Maternal speech was transcribed from the recordings, and measures of maternal lexical repetition were obtained. Standardized language assessments were administered on children with CIs approximately two years after CI activation. Results The findings indicated that measures of lexical repetition were similar among the three groups of mothers, regardless of the hearing status of their infants. In addition, lexical repetition measures were correlated with later language skills in infants with CIs. Conclusions Infants with CIs receive the language input that contains similar lexical repetition properties as that in the speech received by their peers with NH, which is likely to play an important role in child speech processing and language development. These findings provide the knowledge for professionals to coach parents to implement specific language intervention strategies to support language development in infants with hearing loss. Supplemental Material https://doi.org/10.23641/asha.11936322.

Statistical distributions of consonant variants in infant-directed speech: evidence that /t/ may be exceptional

Statistical distributions of phonetic variants in spoken language influence speech perception for both language learners and mature users. We theorized that patterns of phonetic variant processing of consonants demonstrated by adults might stem in part from patterns of early exposure to statistics of phonetic variants in infant-directed (ID) speech. In particular, we hypothesized that ID speech might involve greater proportions of canonical /t/ pronunciations compared to adult-directed (AD) speech in at least some phonological contexts. This possibility was tested using a corpus of spontaneous speech of mothers speaking to other adults, or to their typically-developing infant. Tokens of word-final alveolar stops - including /t/, /d/, and the nasal stop /n/ - were examined in assimilable contexts (i.e., those followed by a word-initial labial and/or velar); these were classified as canonical, assimilated, deleted, or glottalized. Results confirmed that there were significantly more canonical pronunciations in assimilable contexts in ID compared with AD speech, an effect which was driven by the phoneme /t/. These findings suggest that at least in phonological contexts involving possible assimilation, children are exposed to more canonical /t/ variant pronunciations than adults are. This raises the possibility that perceptual processing of canonical /t/ may be partly attributable to exposure to canonical /t/ variants in ID speech. Results support the need for further research into how statistics of variant pronunciations in early language input may shape speech processing across the lifespan.

Preference for Infant-Directed Speech in Infants With Hearing Aids: Effects of Early Auditory Experience

Purpose

It is well established that (a) infants prefer listening to infant-directed speech (IDS) over adult-directed speech (ADS), and (b) IDS facilitates speech, language, and cognitive development, compared with ADS. The main purpose of this study was to determine whether infants with hearing aids (HAs), similar to their peers with normal hearing (NH), show a listening preference for IDS over ADS.

Method

A total of 42 infants participated in the study. In Experiment 1, 9 infants with hearing loss, who had approximately 12 months of experience (mean chronological age of 17.57 months) with HAs, and 9 infants with NH, who had similar chronological age (17.54 months), were tested. In Experiment 2, 10 infants with hearing loss, who had approximately 4 months of experience (mean chronological age of 9.86 months) with HAs, and 14 infants with NH, who had similar chronological age (9.09 months), were tested. Infants were tested on their listening preference in 3 randomized blocks: IDS versus silence, ADS versus silence, and IDS versus ADS blocks, using the central fixation preference procedure.

Results

Experiment 1 showed that infants with HAs, similar to their peers with NH, listened longer to both IDS and ADS relative to silence; however, neither infants with HAs nor infants with NH showed a listening preference for IDS over ADS. In Experiment 2, both infants with HAs and infants with NH showed a listening preference for IDS and ADS relative to silence; in addition, both groups preferred listening to IDS over ADS.

Conclusions

Infants with HAs appear to have sufficient access to the acoustic cues in the speech that allow them to develop an age-equivalent IDS preference. This may be attributed to a combination of being able to use the hearing they do have before receiving HAs and early device fitting. Given previously demonstrated positive associations between IDS preference and language development, this research encourages early interventions focusing on maximizing early auditory experience in infants with hearing loss.

Supplemental Material

https://doi.org/10.23641/asha.6906365.

Attention to speech and spoken language development in deaf children with cochlear implants: a 10-year longitudinal study

Early auditory/language experience plays an important role in language development. In this study, we examined the effects of severe-to-profound hearing loss and subsequent cochlear implantation on the development of attention to speech in children with cochlear implants (CIs). In addition, we investigated the extent to which attention to speech may predict spoken language development in children with CIs. We tested children with CIs and compared them to chronologically age-matched peers with normal hearing (NH) on their attention to speech at four time points post implantation; specifically, less than 1 month, 3 to 6 months, 12 months, and 18 months post implantation. We also collected a variety of well-established speech perception and spoken language measures from the children with CIs in a 10-year longitudinal study. Children with CIs showed reduced attention to speech as compared to their peers with NH at less than 1 month post implantation, but a similar degree of attention to speech as their NH peers during later time points. In addition, attention to speech at 3 to 6 months post implantation predicts speech perception in children with CIs. These results inform language acquisition theories and bring insights into our understanding of early severe-to-profound hearing loss on infants' attention to speech skills. In addition, the findings have significant clinical implications for early intervention on hearing loss, which emphasizes the importance of developing strong listening skills. A video abstract of this article can be viewed at: https://www.youtube.com/watch?v=f7xiYo3Ua08&feature=youtu.be.