Babbling in children with neurodevelopmental disability and validity of a simplified way of measuring canonical babbling ratio

A Pilot Investigation on the Relationship Between Infant Vocal Characteristics at 12 Months and Speech Motor Impairment at 4-5 Years

PURPOSE

The objective of this pilot study was to investigate the relationship between infant vocal characteristics and later speech motor impairment in children at risk for cerebral palsy (CP) to inform the early prediction of speech motor impairment.

METHOD

Vocal complexity, volubility, and consonant inventories of 13 infants at risk of CP were examined at approximately 12 months. We examined their association with later levels of speech motor impairment as measured by the Viking Speech Scale (VSS).

RESULTS

Children in our sample with greater speech motor impairment at age 4 years produced lower rates of developmentally complex vocalizations in infancy but showed no significant differences in vocal stage attainment, volubility, or consonant diversity.

CONCLUSIONS

Our results are in line with trends found in prior literature examining vocal characteristics of infants at risk for speech motor involvement. These results can inform data-driven hypotheses in future studies aimed at the early prediction of speech motor impairment through the study of infant vocal production.

Shared Environment - Different Genes: Speech-Language Development in a Pair of Dizygotic Twins with and Without MECP2 Mutation

This retrospective study compared the speech-language development of a pair of dizygotic twin girls during the first 2 years of life: one with typical development (Twin A) and one with atypical development (Twin B), who was later diagnosed with Rett syndrome (RTT). Audio snippets were extracted from home videos, with nearly equal representation from each child. The audio analysis focused on articulatory complexity, voice characteristics, and linguistic variability. Despite sharing the same social-communicative environment, the twins' speech-language development diverged. From the first to second year of life, articulatory complexity and variability increased in the typically developing Twin A. In contrast, Twin B produced a high number of vocalizations in the 7th month, including canonical sounds with substantial variability. However, her vocalization quantity, complexity, and variability subsequently decreased, resulting in only sporadically discernable canonical vocalizations during her second year. This developmental trajectory points to very early stagnation and regression in Twin B, occurring earlier than typically observed. While Twin B displayed a range of typical vocalization features, deviations in the density and distribution of inspiratory and high-pitched vocalizations during the first year further suggest early speech-language abnormalities in RTT, preceding frank developmental stagnation and regression. As the study relied on limited retrospective data, the findings should be interpreted with caution, and further investigation is needed. Nevertheless, this twin study provides a unique perspective that deepens our understanding of early speech-language developmental profiles in RTT, especially in light of the intertwinement of genetic, individual, and contextual factors.

Segmental trunk control and developmental parameters in children with cerebral palsy aged 24 to 42 months: A cross-sectional study

This study aimed (1) to investigate the relationship between segmental trunk control and motor, cognitive, and language development parameters in children with cerebral palsy (CP) and (2) to compare segmental trunk control levels and motor, language, and cognitive development in children with CP and typically developing (TD) peers. A cross-sectional observational study was conducted with 63 children aged between 24 and 42 months, including those with typical and atypical development. The atypical development group included 30 children with CP ranged from Gross Motor Function Classification System levels I to V (70.0% males, median age: 29 months, interquartile range: 25-36 months), and 33 children in the TD group (69.7% males, median age: 29 months, interquartile range: 26-36 months) included age-matched. Motor, language, and cognitive development domains were evaluated using the Bayley Scales of Infant and Toddler Development, Third Edition, and the level of trunk control was evaluated using the Segmental Assessment of Trunk Control. In children with CP, segmental trunk control was found to be strongly correlated with motor, cognitive, and language development (all P < .001, Spearman r ranged from 0.767-0.927). Furthermore, children with CP had lower segmental trunk control levels and cognitive, language, and motor development results than their TD peers (all P < .001). The strong relationship between segmental trunk control levels and developmental parameters can guide clinicians and therapists in planning and implementing intervention programs designed for children with CP who have difficulties in trunk control.

Vocal Characteristics of Children With Cerebral Palsy and Anarthria

PURPOSE

This study aimed to investigate the vocal characteristics of children with cerebral palsy (CP) and anarthria using the stage model of vocal development.

METHOD

Vocal characteristics of 39 children with CP and anarthria around 4 years of age were analyzed from laboratory-based caregiver-child interactions. Perceptual coding analysis was conducted using the Stark Assessment of Early Vocal Development-Revised to examine vocal complexity, volubility, and consonant diversity.

RESULTS

Children predominately produced vocalizations corresponding to the two earliest stages of vocal development characterized by vowel-like utterances. They showed a limited attainment of consonantal features with low consonant diversity and variably low vocal rates.

CONCLUSIONS

Our results demonstrate that underlying neurological impairments resulting in an anarthric status in children with CP affect the progression of speech motor development and their ability to advance beyond early vocal stages. These findings highlight the importance of considering alternative communication modalities for children demonstrating similar vocal characteristics beyond expected periods of development.

Longitudinal follow-up of hearing, speech, and language skills in 6-year-old children with congenital moderate hearing loss

OBJECTIVES

Children born with moderate hearing loss present with speech and language outcomes at both ends of the spectrum. To explore reasons for this, the objective of this study was to follow up a group of children born with moderate sensorineural hearing loss at 6 years of age (n = 7) by investigating their outcomes in hearing, speech, and language development from time point of hearing aid fitting at 6 months. Another objective was to investigate the relationship between earlier outcomes on precursing variables to the current status in auditory, speech and language development.

METHOD

Earlier data from a project with the same participants of auditory variables, speech, and language development were compared to the current study outcomes at 6 years of age. Children in this study performed standardized tests of phonology (SVANTE), expressive vocabulary (BNT), and speech-in-noise test (Hagerman's sentences). Parents reported on their child's functional auditory performance in everyday life (PEACH), and demographics and general development (questionnaire). Etiology and frequency of speech and language-directed intervention from time point of diagnosis to 6 years of age were collected through medical journals.

RESULTS

Hearing levels were stable over time in all children but one, who had received bilateral cochlear implants. Performance on speech-in-noise testing varied in aided condition (-0.8 to 8, mean 2.65, SD 3.09) and unaided condition (7.2 dB-21.2 dB, mean 12.06, SD 4.82). Scores on the PEACH indicated further review in four of the seven children. Mean group score on consonant proficiency had increased from 3 to 6 years of age and were within age norms. Vocabulary scores were below the norms of children with typical hearing. Outcomes on vocabulary measures at 2.5 years showed strong correlations that were significant to scores on the BNT at 6 years of age (r = 0.87, p = 0.05). Correlations between hours of hearing aid use and vocabulary was not significant at 6 years of age. The frequency of intervention sessions in the first 6 years varied between participants (4-55, mean 19.1, SD 17.1).

CONCLUSION

Despite homogeneous hearing and other background variables in the participants from birth, large individual variations in speech and language outcomes at 6 years of age were found. Considering the many factors involved that impact the development of children with moderate hearing loss, the results suggest that monitoring early precursors in auditory, speech and language development may be helpful in setting commensurate goals for each child. Detecting additional conditions that may pose challenges in future speech and language as early as possible is important. There is ample room for improvement in terms of increasing the frequency of intervention for children with moderate hearing loss and their families.

Follow-up of expressive language and general development at 12, 18 and 36 months for children with no canonical babbling at 10 months

Little is known about the developmental trajectories in children who do not use canonical babbling (CB) at 10 months. The aim was to examine how speech, language, cognitive and motor abilities developed in children without CB. For 15 children identified as not having CB, consonant production, expressive vocabulary and general development were assessed at 12, 18 and 36 months from audio-video recordings. Twelve (79%) children still lacked CB at 12 months. At 18 months, six (40%) had parent-reported expressive vocabulary results below the 10th percentile, and two (14%) did not use dental/alveolar stops. The percentage of consonants correct for the group was at the level of peers at 36 months (89%, SD 0.17), but the group had fewer established target consonants than age norms. Most children had a small expressive vocabulary in comparison with Swedish age norms for younger children as well as with age-matched norms for other Nordic languages. The general development (Bayley-III) for three children (21%) who did not use speech was 1-2 SD below the average range in at least one domain (cognitive, language or motor), but the results for the whole group were within the average range. In conclusion, the heterogeneity in early consonant development in the study group resembles that of children in clinical groups with known risk for speech and language difficulties and the expressive vocabulary resembles that of children with delayed expressive vocabulary. For about one-fifth of the children, the absence of canonical babbling at age 10 months could be seen as an early sign of a more comprehensive developmental disability.

Babbling in extremely premature infants at 12 months corrected age

Babbling is an important precursor to speech in infancy, and deviations from the typical babbling development can predict later difficulties in speech, language, and communication. This cross-sectional study aimed to investigate babbling and early speech in Swedish extremely premature infants. Samples of babbling were collected from 20 extremely premature infants (EPT group) at the corrected age of 12 months. Data collection was home-based and consisted of an audio-video recording of each infant playing with a parent. Presence of canonical babbling (CB), and three oral stop variables distinctive of typical babbling, and consonant inventory were assessed. The assessment was performed during a standardised observation of babbling. Data from the EPT group were compared to previously collected data of a reference group of 20 10-month-old infants without known medical diagnoses. The results showed that the EPT group had a lower proportion of infants producing CB, and that they used a significantly smaller consonant inventory compared to the reference group. Although not statistically significant, oral stops were less frequently found in the EPT group. The findings of a restricted consonant inventory and low proportion of CB in the EPT group are not surprising considering that the group has been found to be at risk of speech and language delay in toddlerhood. Still, further research is needed to explore whether babbling at 12 months can predict speech and language skills at an older age in extremely premature infants.

Vocal Characteristics of Infants at Risk for Speech Motor Involvement: A Scoping Review

PURPOSE

The purpose of this scoping review was to (a) summarize methodological characteristics of studies examining vocal characteristics of infants at high risk for neurological speech motor involvement and (b) report the state of the high-quality evidence on vocal characteristic trends of infants diagnosed or at high risk for cerebral palsy (CP).

METHOD

The PRISMA (Preferred Reporting Items of Systematic Reviews and Meta-Analyses) extension for scoping reviews was followed for reporting our review. Studies measured prelinguistic vocal characteristics of infants under 24 months with birth risk or genetic conditions known to commonly present with speech motor involvement. Fifty-five studies met criteria for Part 1. Eleven studies met criteria for synthesis in Part 2.

RESULTS

A smaller percentage of studies examined infants with or at risk for CP compared to studies examining genetic conditions such as Down syndrome. The median year of publication was 1999, with a median sample size of nine participants. Most studies were conducted in laboratory settings and used human coding of vocalizations produced during caregiver-child interactions. Substantial methodological differences were noted across all studies. A small number of high-quality studies of infants with or at risk for CP revealed high rates of marginal babbling, low rates of canonical babbling, and limited consonant diversity under 24 months. Mixed findings were noted across studies of general birth risk factors.

CONCLUSIONS

There is limited evidence available to support the early detection of speech motor involvement. Large methodological differences currently impact the ability to synthesize findings across studies. There is a critical need to conduct longitudinal research with larger sample sizes and advanced, modern technologies to detect vocal precursors of speech impairment to support the accurate diagnosis and prognosis of speech development in infants with CP and other clinical populations.

Marginal and Canonical Babbling in 10 Infants at Risk for Cerebral Palsy

PURPOSE

This study is a preliminary quantification and characterization of the development of marginal and canonical syllable patterns in 10 infants at risk for cerebral palsy (CP).

METHOD

We calculated marginal and canonical babbling ratios from parent-infant laboratory recordings of 10 infants at two time points, approximately 13 and 16 months of age. The frequency and diversity of labial, coronal, and velar types of marginal and canonical syllables were also examined. Differences across three outcome groups were compared: infants later diagnosed with CP (n = 3, CP group), risk of CP due to ongoing gross motor delays (n = 4, risk group), and current typically developing status with resolved gross motor delays (n = 3, TDx group). Performance on the Mullen Scales was included for perspective on cognitive development.

RESULTS

Higher marginal syllable ratios were observed in the CP and risk groups than the TDx group. An increasing canonical syllable ratio across the two ages was consistently observed in the TDx group. The TDx group produced a greater frequency and diversity of canonical syllable types than the risk and CP groups, and of marginal syllable types than the CP group.

CONCLUSIONS

This study offers preliminary support for the possibility that speech motor impairment in infants with CP have the potential to be observed and quantified early in vocal development prior to the expected onset of first words. Prolonged rates of marginal syllable forms may be suggestive of speech motor impairment; however, additional longitudinal outcome data over a longer time course and a larger sample of infants are needed to provide further support for this possibility.

Prosodic signatures of ASD severity and developmental delay in preschoolers

Atypical prosody in speech production is a core feature of Autism Spectrum Disorder (ASD) that can impact everyday life communication. Because the ability to modulate prosody develops around the age of speech acquisition, it might be affected by ASD symptoms and developmental delays that emerge at the same period. Here, we investigated the existence of a prosodic signature of developmental level and ASD symptom severity in a sample of 74 autistic preschoolers. We first developed an original diarization pipeline to extract preschoolers' vocalizations from recordings of naturalistic social interactions. Using this novel approach, we then found a robust voice quality signature of ASD developmental difficulties in preschoolers. Furthermore, some prosodic measures were associated with one year later outcome in participants who had not acquired speech yet. Altogether, our results highlight the potential benefits of automatized diarization algorithms and prosodic metrics for digital phenotyping in psychiatry, helping clinicians establish early diagnosis and prognosis.

Inter-rater reliability in classification of canonical babbling status based on canonical babbling ratio in infants with isolated cleft palate randomised to Timing of Primary Surgery for Cleft Palate (TOPS)

Canonical babbling (CB) is commonly defined as present when at least 15% of all syllables produced are canonical, in other words a canonical babbling ratio (CBR) ≥0.15. However, there is limited knowledge about inter-rater reliability in classification of CB status based on CBR and inter-rater differences in assessment of CBR. We investigated inter-rater reliability of experienced Speech Language Therapists (SLTs) on: classification of CB status based on CBR ≥ 0.15, CBRs and the total number of syllables per infant used to calculate CBR.Each infant (n = 484) was video-recorded at a clinical site in play interaction with their parent as part of the randomised controlled trial Timing of Primary Surgery for Cleft Palate. Each recording was subsequently assessed by three independent SLTs, from a pool of 29 SLTs. They assessed the recordings in real time.The three assessing SLTs agreed in classification of CB status in 423 (87.4%) infants, with higher complete agreement for canonical (91%; 326/358) than non-canonical (77%; 97/126). The average difference in CBR and total number of syllables identified between the SLT assessments of each infant was 0.12 and 95, respectively.This study provided new evidence that one trained SLT can reliably classify CB status (CBR ≥ 0.15) in real time when there is clear distinction between the observed CBR and the boundary (0.15); however, when the observed CBR approaches the boundary multiple SLT assessments are beneficial. Thus, we recommend to include assessment of inter-rater reliability, if the purpose is to compare CBR and total syllable count across infants or studies.Trial registration number here: www.clinicaltrials.gov, identifier NCT00993551.

A Probe Study on Vocal Development in Two Infants at Risk for Cerebral Palsy

The present work examined canonical babbling ratios longitudinally as a measure of onset and consolidation of canonical babbling in two infants at risk of cerebral palsy (CP) between 5 and 16 months. Ten typically developing infants were included for comparison at 6, 9, 12, and 16-19 months. Canonical babbling ratios (CBRs) were calculated from 5-min segments, and follow-up diagnostic outcomes were collected between 24 and 33 months. The two infants at risk demonstrated low CBR growth trajectories compared to the typical infant group, and slightly different patterns of consolidation. The two infants at risk were later diagnosed with different levels of CP and speech impairment severity. All infants demonstrated greater variability than expected. Studying canonical babbling and other prelinguistic milestones in this population may inform our perspective of the involvement of the motor system in the vocal domain. Additional implications on the analysis of canonical babbling using all-day home recordings are discussed.

Implementation of an Early Communication Intervention for Young Children with Cerebral Palsy Using Single-Subject Research Design

The implementation of an intervention protocol aimed at increasing vocal complexity in three pre-linguistic children with cerebral palsy (two males, starting age 15 months, and one female, starting age 16 months) was evaluated utilising a repeated ABA case series design. The study progressed until the children were 36 months of age. Weekly probes with trained and untrained items were administered across each of three intervention blocks. Successive blocks targeted more advanced protophone production and speech movement patterns, individualised for each participant. Positive treatment effects were seen for all participants in terms of a greater rate of achievement of target protophone categories and speech movement patterns. Tau coefficients for trained items demonstrated overall moderate to large AB phase contrast effect sizes, with limited evidence of generalisation to untrained items. Control items featuring protophones and speech movements not targeted for intervention showed no change across phases for any participant. Our data suggest that emerging speech-production skills in prelinguistic infants with CP can be positively influenced through a multimodal intervention focused on capitalising on early periods of plasticity when language learning is most sensitive.

Emerging Verbal Functions in Early Infancy: Lessons from Observational and Computational Approaches on Typical Development and Neurodevelopmental Disorders

OBJECTIVES

Research on typically developing (TD) children and those with neurodevelopmental disorders and genetic syndromes was targeted. Specifically, studies on autism spectrum disorder, Down syndrome, Rett syndrome, fragile X syndrome, cerebral palsy, Angelman syndrome, tuberous sclerosis complex, Williams-Beuren syndrome, Cri-du-chat syndrome, Prader-Willi syndrome, and West syndrome were searched. The objectives are to review observational and computational studies on the emergence of (pre-)babbling vocalisations and outline findings on acoustic characteristics of early verbal functions.

METHODS

A comprehensive review of the literature was performed including observational and computational studies focusing on spontaneous infant vocalisations at the pre-babbling age of TD children, individuals with genetic or neurodevelopmental disorders.

RESULTS

While there is substantial knowledge about early vocal development in TD infants, the pre-babbling phase in infants with neurodevelopmental and genetic syndromes is scarcely scrutinised. Related approaches, paradigms, and definitions vary substantially and insights into the onset and characteristics of early verbal functions in most above-mentioned disorders are missing. Most studies focused on acoustic low-level descriptors (e.g. fundamental frequency) which bore limited clinical relevance. This calls for computational approaches to analyse features of infant typical and atypical verbal development.

CONCLUSIONS

Pre-babbling vocalisations as precursor for future speech-language functions may reveal valuable signs for identifying infants at risk for atypical development. Observational studies should be complemented by computational approaches to enable in-depth understanding of the developing speech-language functions. By disentangling features of typical and atypical early verbal development, computational approaches may support clinical screening and evaluation.

Infants later diagnosed with autism have lower canonical babbling ratios in the first year of life

BACKGROUND

Canonical babbling-producing syllables with a mature consonant, full vowel, and smooth transition-is an important developmental milestone that typically occurs in the first year of life. Some studies indicate delayed or reduced canonical babbling in infants at high familial likelihood for autism spectrum disorder (ASD) or who later receive an ASD diagnosis, but evidence is mixed. More refined characterization of babbling in the first year of life in infants with high likelihood for ASD is needed.

METHODS

Vocalizations produced at 6 and 12 months by infants (n = 267) taking part in a longitudinal study were coded for canonical and non-canonical syllables. Infants were categorized as low familial likelihood (LL), high familial likelihood diagnosed with ASD at 24 months (HL-ASD) or not diagnosed (HL-Neg). Language delay was assessed based on 24-month expressive and receptive language scores. Canonical babble ratio (CBR) was calculated by dividing the number of canonical syllables by the number of total syllables. Generalized linear (mixed) models were used to assess the relationship between group membership and CBR, controlling for site, sex, and maternal education. Logistic regression was used to assess whether canonical babbling ratios at 6 and 12 months predict 24-month diagnostic outcome.

RESULTS

No diagnostic group differences in CBR were detected at 6 months, but HL-ASD infants produced significantly lower CBR than both the HL-Neg and LL groups at 12 months. HL-Neg infants with language delay also showed reduced CBR at 12 months. Neither 6- nor 12-month CBR was significant predictors of 24-month diagnostic outcome (ASD versus no ASD) in logistic regression.

LIMITATIONS

Small numbers of vocalizations produced by infants at 6 months may limit the reliability of CBR estimates. It is not known if results generalize to infants who are not at high familial likelihood, or infants from more diverse racial and socioeconomic backgrounds.

CONCLUSIONS

Lower canonical babbling ratios are apparent by the end of the first year of life in ASD regardless of later language delay, but are also observed for infants with later language delay without ASD. Canonical babbling may lack specificity as an early marker when used on its own.

Vocalisation Repertoire at the End of the First Year of Life: An Exploratory Comparison of Rett Syndrome and Typical Development

Rett syndrome (RTT) is a rare, late detected developmental disorder associated with severe deficits in the speech-language domain. Despite a few reports about atypicalities in the speech-language development of infants and toddlers with RTT, a detailed analysis of the pre-linguistic vocalisation repertoire of infants with RTT is yet missing. Based on home video recordings, we analysed the vocalisations between 9 and 11 months of age of three female infants with typical RTT and compared them to three age-matched typically developing (TD) female controls. The video material of the infants had a total duration of 424 min with 1655 infant vocalisations. For each month, we (1) calculated the infants' canonical babbling ratios with CBRUTTER, i.e., the ratio of number of utterances containing canonical syllables to total number of utterances, and (2) classified their pre-linguistic vocalisations in three non-canonical and four canonical vocalisation subtypes. All infants achieved the milestone of canonical babbling at 9 months of age according to their canonical babbling ratios, i.e. CBRUTTER ≥ 0.15. We revealed overall lower CBRsUTTER and a lower proportion of canonical pre-linguistic vocalisations consisting of well-formed sounds that could serve as parts of target-language words for the RTT group compared to the TD group. Further studies with more data from individuals with RTT are needed to study the atypicalities in the pre-linguistic vocalisation repertoire which may portend the later deficits in spoken language that are characteristic features of RTT.

Clinical utilisation of the Infant Monitor of vocal Production (IMP) for early identification of communication impairment in young infants at-risk of cerebral palsy: a prospective cohort study

AIM

To report prospective longitudinal data of early vocaliszations of infants identified "at-risk" of cerebral palsy (CP) for early identification of communication impairment.

METHOD

This case-control longitudinal prospective cohort study reports on the assessment of 36 infants, 18 identified as at-risk of CP at the time of enrolment and 18 typically developing (TD) children, at three time points: 6 months, 9 months and 12 months of age, Data were obtained through criterion and norm referenced assessments of vocaliszation behaviors.

RESULTS

Early vocal behaviors of infants identified as at-risk of CP did not differ from their age matched peers at 6 months of age, however, significant group differences emerged at 9 and 12 months when pre-canonical and canonical babble typically emerge. Generalized linear mixed models analysis showed that the rate of development of early language ability and more complex speech-related vocal behaviors was slower for infants at risk of CP when compared to TD infants, with over 75% of infants with CP showing below normal vocal production and impaired language by 12 months of age.

INTERPRETATION

Our data suggest characteristics of infant vocalizations associated with pre-canonical and canonical babbling provide a strong evidence base for predicting communication outcomes in infants at risk of CP.

Early Vocal Development in Tuberous Sclerosis Complex

BACKGROUND

Our goal was to assess for the first time early vocalizations as precursors to speech in audio-video recordings of infants with tuberous sclerosis complex (TSC).

METHODS

We randomly selected 40 infants with TSC from the TSC Autism Center of Excellence Research Network dataset. Using human observers, we analyzed 74 audio-video recordings within a flexible software-based coding environment. During the recordings, infants were engaged in developmental testing. We determined syllables per minute (volubility), the number of consonant-vowel combinations, such as 'ba' (canonical babbling), and the canonical babbling ratio (canonical syllables/total syllables) and compared the data with two groups of typically developing (TD) infants. One comparison group's data had come from a laboratory setting, while the other's had come from all-day Language Environment Analysis recordings at home.

RESULTS

Compared with TD infants in laboratory and all-day Language Environment Analysis recordings, entry into the canonical babbling stage was delayed in the majority of infants with TSC, and the canonical babbling ratio was low (TD mean = 0.346, SE = 0.19; TSC mean = 0.117, SE = 0.023). Volubility level in infants with TSC was less than half that of TD infants (TD mean = 9.82, SE = 5.78; TSC mean = 3.99, SE = 2.16).

CONCLUSIONS

Entry into the canonical stage and other precursors of speech development were delayed in infants with TSC and may signal poor language and developmental outcomes. Future studies are planned to assess prediction of language and developmental outcomes using these measures in a larger sample and in more precisely comparable recording circumstances.

Canonical babbling ratio - Concurrent and predictive evaluation of the 0.15 criterion

INTRODUCTION

Canonical babbling ratio (CBR) is a commonly used measure to quantify canonical babbling (CB), and 0.15 is the commonly accepted criterion for the canonical babbling stage. However, this has not been thoroughly investigated. The aim of this study was to evaluate the validity of this criterion using concurrent and predictive comparisons.

METHODS

Longitudinal data from 50 children recruited in different clinical projects were used. At 10 months of age, CBR was calculated based on counted utterances from audio-video recorded parent-child interactions. The videos were also assessed by CB observation, where an observer made an overall judgement on whether the child was in the canonical babbling stage or not. For the concurrent evaluation, CBR was compared to CB observation as a reference test, using area under the curve (AUC). The criterion resulting in the best combination of sensitivity and specificity was identified using positive likelihood ratios. In the predictive comparisons CBR was analyzed as a predictor of speech/language difficulties at 30-36 months. Participants presenting with difficulties in consonant production and/or parent-reported vocabulary were considered to have speech/language difficulties. Sensitivity and specificity were compared for CBR using the 0.15 criterion and the new criterion identified in this study.

RESULTS

An AUC of 0.87 indicated that CBR is a valid measure of canonical babbling in 10-month-old children. The best combination of sensitivity and specificity was found at a criterion of 0.14 (sensitivity 0.96, specificity 0.70). In the predictive comparison, CBR with a 0.14 or 0.15 criterion revealed the same sensitivity (0.71) but 0.14 showed a slightly better specificity (0.52 versus 0.42).

CONCLUSIONS

CBR is a valid measure of CB (at 10 months). However, when using CBR to classify children's babbling as canonical or non-canonical, researchers need to carefully consider the implications of the chosen criterion.

Speech and Language in 5-year-olds with Different Neurological Disabilities and the Association between Early and Later Consonant Production

The primary aim was to describe speech and language abilities in a clinical group of verbal 5-year-old children diagnosed with neurological disability (ND) in infancy, and the secondary aim was to trace precursors to consonant production at age 5 years (T2) in data from 12 to 22 months (T1). The participants (n = 11, with Down syndrome (DS), cerebral palsy, and chromosomal deletion syndromes) were tested with a battery of speech and language tests. Consonant production at T2 was compared to data on consonant use at T1. At T2, two participants had age appropriate speech and language and another three had age-appropriate speech, but low results on language tests. The remaining six participants had severe speech and language difficulties. Participants with DS had significantly lower results on consonant production measures. An association between consonant production at T1 and T2 for participants with DS indicates that number of different true consonants might be a predictive measure when evaluating young children with DS.

Prelexical phonetic and early lexical development in German-acquiring infants: canonical babbling and first spoken words

Prelexical phonetic capacities have widely been described to be a precursor for later speech and language development. However, studies so far varied greatly in the measurements used for the detection of canonical babbling onset or the description of infants' phonetic capacities at one or more set time points. The comparability of results is, therefore, questionable. Thus, the aims of this study were to investigate the associations between (1) different measurements of CBO, (2) different aspects of phonetic capacity at the age of 9 months and (3) age of CBO and phonetic capacities at 9 months. A further aim (4) was to explore whether one of the measures would be suitable to predict the age of word onset (WO) in 20 healthy German-acquiring individuals. The data were derived from monthly recorded spontaneous speech samples between 0 and 18 months. It was found that the different applied prelexical measures equally well serve as valid estimators for the detection of CBO or of infants' phonetic capacities. Further, age of CBO and phonetic capacities at 9 months were significantly associated even though the age of CBO did not reliably predict phonetic capacities. Prelexical measures and WO were not related. Reasons for no indication of a significant association are discussed.

Functionally Flexible Signaling and the Origin of Language

At the earliest break of ancient hominins from their primate relatives in vocal communication, we propose a selection pressure on vocal fitness signaling by hominin infants. Exploratory vocalizations, not tied to expression of distress or immediate need, could have helped persuade parents of the wellness and viability of the infants who produced them. We hypothesize that hominin parents invested more in infants who produced such signals of fitness plentifully, neglecting or abandoning them less often than infants who produced the sounds less frequently. Selection for such exploratory vocalization provided a critically important inclination and capability relevant to language, we reason, because the system that encouraged spontaneous vocalization also made vocalization functionally flexible to an extent that has not been observed in any other animal. Although this vocal flexibility did not by itself create language, it provided an essential foundation upon which language would evolve through a variety of additional steps. In evaluating this speculation, we consider presumable barriers to evolving language that are thought to be implications of Darwinian Theory. It has been claimed that communication always involves sender self-interest and that self-interest leads to deceit, which is countered through clever detection by receivers. The constant battle of senders and receivers has been thought to pose an insuperable challenge to honest communication, which has been viewed as a requirement of language. To make communication honest, it has been proposed that stable signaling requires costly handicaps for the sender, and since language cannot entail high cost, the reasoning has suggested an insurmountable obstacle to the evolution of language. We think this presumed honesty barrier is an illusion that can be revealed by recognition of the fact that language is not inherently honest and in light of the distinction between illocutionary force and semantics. Our paper also considers barriers to the evolution of language (not having to do with honesty) that we think may have actually played important roles in preventing species other than humans from evolving language.

Früherkennung von Entwicklungsstörungen: Kanonisches Lallen (k)‌ein diagnostischer Marker‍(!)?

Zusammenfassung. Theoretischer Hintergrund: Forschungsergebnisse zum frühen Spracherwerb bei Kindern mit spät erkannten Entwicklungsstörungen sind inkonsistent und angesichts unterschiedlicher Forschungsparadigmen und Definitionen nur bedingt vergleichbar. Fragestellung: Ziel dieser Übersichtsarbeit ist es, das Potenzial früher verbaler Fähigkeiten, vor allem des kanonischen Lallens, als Marker zur Früherkennung von Autismus-Spektrum-Störung, Rett-Syndrom und Fragilem-X-Syndrom zu beschreiben. Methode: Übersichtsarbeit über retrospektive und prospektive Studien zu frühen verbalen Fähigkeiten in der Prodromalphase dieser Störungsbilder. Ergebnisse: Einige Kinder mit spät erkannten Entwicklungsstörungen erwerben das kanonische Lallen nach dem kritischen Zeitfenster von 6 bis 10 Monaten und/oder haben oft qualitative Veränderungen in ihren Lautäußerungen. Diskussion und Schlussfolgerung: Eine abweichende Entwicklung des kanonischen Lallens kann auf spätere atypische Entwicklung hinweisen. Als funktioneller Marker für die spezifische Früherkennung von Entwicklungsstörungen scheint dieser Erwerbsmeilenstein jedoch nicht geeignet. Linguistische und signalbasierte Detailanalysen frühkindlicher Vokalisationen könnten zukünftig einen entscheidenden Beitrag hierzu leisten.

Canonical Babbling and Early Consonant Development Related to Hearing in Children With Otitis Media With Effusion With or Without Cleft Palate

OBJECTIVE

To investigate and compare babbling, early consonant production and proficiency from 10 to 36 months of age and its relationship with hearing in children with otitis media with effusion (OME) with or without cleft palate.

DESIGN

Prospective, longitudinal group comparison study.

SETTING

University hospital.

PARTICIPANTS

Fifteen children born with nonsyndromic cleft palate with or without cleft lip (CP±L) and 15 age-matched children with hearing loss (HL) associated with OME but without cleft palate (noncleft group).

MAIN OUTCOME MEASURES

Canonical babbling (CB) and early consonant variables (presence of oral stops, anterior stops, dental/alveolar stops, number of different true consonants) at 10 and 18 months, and percentage of consonants correct proficiency (PCC) at 36 months.

RESULTS

A total of 54% of the CP±L group and 77% of the noncleft group had CB. The noncleft group had a significantly higher prevalence of all consonant variables. Percentage of consonants correct was 61.9% in the CP±L group and 81.6% in the noncleft group. All early consonant variables except CB were significantly related to PCC. Hearing sensitivity at 18 and 30 months correlated with PCC and explained 40% of the variation.

CONCLUSIONS

Mild HL impacted presence of CB at 10 months and was related to consonant proficiency at 36 months in children with HL associated with OME and children with cleft palate. The noncleft group showed results at 36 months similar to children with normal hearing; however, the CP±L group did not. Although the cleft palate may have a bigger impact on the speech development, management of hearing sensitivity would also be beneficial.

Validation of a Parent Report Tool for Monitoring Early Vocal Stages in Infants

Purpose Tracking of infants' progression through early vocal stages supports the identification of children at risk for language delays and guides early intervention for children with disabilities. However, few clinical tools are available to support systematic assessment of infants' early vocal development. This study sought to develop and conduct a preliminary evaluation of the validity of a parent report tool designed for this purpose, the Vocal Development Landmarks Interview (VDLI). Method The participants were caregivers of 160 typically developing 6- to 21-month-old infants. Caregivers participated in the VDLI, which uses audio samples of authentic infant vocalizations to query parents regarding their children's vocal behaviors. The VDLI yields 3 subscale scores (Precanonical, Canonical, and Word) and a total score. Caregivers also completed sections of the Communication and Symbolic Behavior Scales Developmental Profile Caregiver Questionnaire that yielded a speech composite score. Results Cross-sectional analyses showed that the VDLI is sensitive to age and captures the expected developmental trajectories of vocal behaviors. A strong, positive correlation ( r = .93) was found between VDLI total scores and the Communication and Symbolic Behavior Scales Developmental Profile speech composite score, indicating concurrent validity. Subscales were found to be internally consistent. Conclusion Preliminary findings of sensitivity to age, concurrent validity, and internal consistency provide support for the eventual use of the VDLI as a clinical tool for tracking vocal and early verbal milestones. Future research will explore the level of concordance between parent report and researcher observations of child vocal behaviors. Supplemental Material https://doi.org/10.23641/asha.8330003.

Canonical Babbling: A Marker for Earlier Identification of Late Detected Developmental Disorders?

PURPOSE OF REVIEW

To summarize findings about the emergence and characteristics of canonical babbling in children with late detected developmental disorders (LDDDs), such as autism spectrum disorder, Rett syndrome, and fragile X syndrome. In particular, we ask whether infants' vocal development in the first year of life contains any markers that may contribute to earlier detection of these disorders.

RECENT FINDINGS

Only a handful studies have investigated canonical babbling in infants with LDDDs. With divergent research paradigms and definitions applied, findings on the onset and characteristics of canonical babbling are inconsistent and difficult to compare. Infants with LDDDs showed reduced likelihood to produce canonical babbling vocalizations. If achieved, this milestone was more likely to be reached beyond the critical time window of 5-10 months.

SUMMARY

Canonical babbling appears promising as a potential marker for early detection of infants at risk for developmental disorders. In-depth studies on babbling characteristics in LDDDs are warranted.