The articulatory basis of babbling

Infant vocal productions coincide with body movements

Producing recognizable words is a difficult motor task; a one-syllable word can require the coordination of over 80 muscles. Thus, it is not surprising that the development of word productions in infancy lags considerably behind receptive language and is a known limiting factor in language development. A large literature has focused on the vocal apparatus, its articulators, and language development. There has been limited study of the relations between non-speech motor skills and the quality of early speech productions. Here we present evidence that the spontaneous vocalizations of 9- to 24-month-old infants recruit extraneous, synergistic co-activations of hand and head movements and that the temporal precision of the co-activation of vocal and extraneous muscle groups tightens with age and improved recognizability of speech. These results implicate an interaction between the muscle groups that produce speech and other body movements and provide new empirical pathways for understanding the role of motor development in language acquisition. RESEARCH HIGHLIGHTS: The spontaneous vocalizations of 9- to 24-month-old infants recruit extraneous, synergistic co-activations of hand and head movements. The temporal precision of these hand and head movements during vocal production tighten with age and improved speech recognition. These results implicate an interaction between the muscle groups producing speech with other body movements. These results provide new empirical pathways for understanding the role of motor development in language acquisition.

The Predictability of Naturalistic Evaluation of All-Day Recordings for Speech and Language Development

OBJECTIVES

The study aimed to investigate the predictive potential of language environment and vocal development status measures obtained through integrated analysis of Language ENvironment Analysis (LENA) recordings during the prelinguistic stage for subsequent speech and language development in Korean-acquiring children. Specifically, this study explored whether measures from both LENA-automated analysis and human coding at 6-8 months and 12-14 months of age predict vocabulary and phonological development at 18-20 months.

METHOD

One-day home recordings from 20 children were collected using a LENA recorder at 6-8 months, 12-14 months, and 18-20 months. Both LENA-automated measures and measures from human coding were obtained from recordings at 6-8 months and 12-14 months. The number of different words, consonant inventory, and utterance structure inventory were identified from recordings of 18-20 months. Correlation and multiple regression analyses were performed to investigate whether measures related to early language environment and child vocalization at 6-8 months and 12-14 months were predictive of vocabulary and phonological measures at 18-20 months.

RESULTS

The results showed that the two main LENA-automated measures, conversational turn count (CTC) and child vocalization count, were positively correlated with all vocabulary and phonological measures at 18-20 months. Multiple regression analysis revealed that CTC during the prelinguistic stages was the most significant predictor of a number of different words, consonant inventory, and utterance structure inventory at 18-20 months. Also, adult word count in LENA-automated measures, child-directed speech ratio, and canonical babbling ratio measured by human coding significantly predicted some vocabulary and phonological measures at 18-20 months.

CONCLUSION

This study highlights the multifaceted nature of language acquisition and collectively emphasizes the value of considering both quantitative and qualitative aspects of language input to understand early language development in children.

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.

Acoustic characteristics of sibilant fricatives and affricates in Mandarin-speaking children with cochlear implants

The purpose of the study was to examine the acoustic features of sibilant fricatives and affricates produced by prelingually deafened Mandarin-speaking children with cochlear implants (CIs) in comparison to their age-matched normal-hearing (NH) peers. The speakers included 21 children with NH aged between 3.25 and 10 years old and 35 children with CIs aged between 3.77 and 15 years old who were assigned into chronological-age-matched and hearing-age-matched subgroups. All speakers were recorded producing Mandarin words containing nine sibilant fricatives and affricates (/s, ɕ, ʂ, ts, tsʰ, tɕ, tɕʰ, tʂ, tʂʰ/) located at the word-initial position. Acoustic analysis was conducted to examine consonant duration, normalized amplitude, rise time, and spectral peak. The results revealed that the CI children, regardless of whether chronological-age-matched or hearing-age-matched, approximated the NH peers in the features of duration, amplitude, and rise time. However, the spectral peaks of the alveolar and alveolopalatal sounds in the CI children were significantly lower than in the NH children. The lower spectral peaks of the alveolar and alveolopalatal sounds resulted in less distinctive place contrast with the retroflex sounds in the CI children than in the NH peers, which might partially account for the lower intelligibility of high-frequency consonants in children with CIs.

Life of p: A consonant older than speech

Which sounds composed the first spoken languages? Archetypal sounds are not phylogenetically or archeologically recoverable, but comparative linguistics and primatology provide an alternative approach. Labial articulations are the most common speech sound, being virtually universal across the world's languages. Of all labials, the plosive 'p' sound, as in 'Pablo Picasso', transcribed /p/, is the most predominant voiceless sound globally and one of the first sounds to emerge in human infant canonical babbling. Global omnipresence and ontogenetic precocity imply that /p/-like sounds could predate the first major linguistic diversification event(s) in humans. Indeed, great ape vocal data support this view, namely, the only cultural sound shared across all great ape genera is articulatorily homologous to a rolling or trilled /p/, the 'raspberry'. /p/-like labial sounds represent an 'articulatory attractor' among living hominids and are likely among the oldest phonological features to have ever emerged in linguistic systems.

Review of methods for conducting speech research with minimally verbal individuals with autism spectrum disorder

The purpose of this paper was to review best-practice methods of collecting and analyzing speech production data from minimally verbal autistic speakers. Data on speech production data in minimally verbal individuals are valuable for a variety of purposes, including phenotyping, clinical assessment, and treatment monitoring. Both perceptual ("by ear") and acoustic analyses of speech can reveal subtle improvements as a result of therapy that may not be apparent when correct/incorrect judgments are used. Key considerations for collecting and analyzing speech production data from this population are reviewed. The definition of "minimally verbal" that is chosen will vary depending on the specific hypotheses investigated, as will the stimuli to be collected and the task(s) used to elicit them. Perceptual judgments are ecologically valid but subject to known sources of bias; therefore, training and reliability procedures for perceptual analyses are addressed, including guidelines on how to select vocalizations for inclusion or exclusion. Factors to consider when recording and acoustically analyzing speech are also briefly discussed. In summary, the tasks, stimuli, training methods, analysis type(s), and level of detail that yield the most reliable data to answer the question should be selected. It is possible to obtain rich high-quality data even from speakers with very little speech output. This information is useful not only for research but also for clinical decision-making and progress monitoring.

Bye-Bye Bunny: Place and Manner Sequences in Children's C1VC2V-Shaped Words

PURPOSE

Place and manner of articulation in American English-learning children's salient consonant-vowel-consonant-vowel (C₁VC₂V) target words (e.g., baby, bunny, and cookie) were compared with their actual productions of these words. We hypothesized that target words with repeated place and/or manner characteristics in C₁VC₂V consonant sequences would be matched in children's actual productions more frequently than target words with variegated place and manner sequences. This hypothesis was based on a proposal that children use available production system capacities to produce salient word forms derived from perceptual input on those word forms.

METHOD

Place and manner sequences were analyzed in 2,092 tokens of C₁VC₂V target words produced by 18 typically developing children in the single-word period. All data were from these children's spontaneous functional speech in a familiar speaking context. Both target word forms and actual child productions of those targets were analyzed.

RESULTS

Results indicated that C₁VC₂V word target sequences predominantly consisted of repetitions in both place and manner of articulation (e.g., labial-labial, stop-stop). Targets with repetitions of consonant sequences were matched more frequently than targets with variegated sequences for both place and manner (e.g., labial-coronal, stop-nasal) in these children's actual productions. Results also indicated that C₁VC₂V target words beginning with a labial consonant (e.g., baby, bunny, and piggy) were matched in children's actual productions more frequently than words with coronal or dorsal consonant onsets (e.g., daddy and cookie).

DISCUSSION

In C₁VC₂V word forms, occurring in early output, children's actual productions matched their target word sequences when the words consisted of repeated sequences in both place and manner. These results suggest that salient target words with repeated sequences may help children support increases in their repertoire of meaningful vocalizations during the transition from babbling to meaningful speech.

Auditory-motor mapping training: Testing an intonation-based spoken language treatment for minimally verbal children with autism spectrum disorder

We tested an intonation-based speech treatment for minimally verbal children with autism (auditory-motor mapping training, AMMT) against a nonintonation-based control treatment (speech repetition therapy, SRT). AMMT involves singing, rather than speaking, two-syllable words or phrases. In time with each sung syllable, therapist and child tap together on electronic drums tuned to the same pitches, thus coactivating shared auditory and motor neural representations of manual and vocal actions, and mimicking the "babbling and banging" stage of typical development. Fourteen children (three females), aged 5.0-10.8, with a mean Autism Diagnostic Observation Schedule-2 score of 22.9 (SD = 2.5) and a mean Kaufman Speech Praxis Test raw score of 12.9 (SD = 13.0) participated in this trial. The main outcome measure was percent syllables approximately correct. Four weeks post-treatment, AMMT resulted in a mean improvement of +12.1 (SE = 3.8) percentage points, compared to +2.8 (SE = 5.7) percentage points for SRT. This between-group difference was associated with a large effect size (Cohen's d = 0.82). Results suggest that simultaneous intonation and bimanual movements presented in a socially engaging milieu are effective factors in AMMT and can create an individualized, interactive music-making environment for spoken-language learning in minimally verbal children with autism.

Long-range sequential dependencies precede complex syntactic production in language acquisition

To convey meaning, human language relies on hierarchically organized, long-range relationships spanning words, phrases, sentences and discourse. As the distances between elements (e.g. phonemes, characters, words) in human language sequences increase, the strength of the long-range relationships between those elements decays following a power law. This power-law relationship has been attributed variously to long-range sequential organization present in human language syntax, semantics and discourse structure. However, non-linguistic behaviours in numerous phylogenetically distant species, ranging from humpback whale song to fruit fly motility, also demonstrate similar long-range statistical dependencies. Therefore, we hypothesized that long-range statistical dependencies in human speech may occur independently of linguistic structure. To test this hypothesis, we measured long-range dependencies in several speech corpora from children (aged 6 months-12 years). We find that adult-like power-law statistical dependencies are present in human vocalizations at the earliest detectable ages, prior to the production of complex linguistic structure. These linguistic structures cannot, therefore, be the sole cause of long-range statistical dependencies in language.

Simulating Speech Error Patterns Across Languages and Different Datasets

Children's speech acquisition is influenced by universal and language-specific forces. Some speech error patterns (or phonological processes) in children's speech are observed in many languages, but the same error pattern may have different effects in different languages. We aimed to explore phonological effects of the same speech error patterns across different languages, target audiences and discourse modes, using a novel method for large-scale corpus investigation. As an additional aim, we investigated the face validity of five different phonological effect measures by relating them to subjective ratings of assumed effects on intelligibility, as provided by practicing speech-language pathologists. Six frequently attested speech error patterns were simulated in authentic corpus data: backing, fronting, stopping, /r/-weakening, cluster reduction and weak syllable deletion-each simulation resulting in a "misarticulated" version of the original corpus. Phonological effects were quantified using five separate metrics of phonological complexity and distance from expected target forms. Using Swedish child-speech data as a reference, phonological effects were compared between this reference and a) child speech in Norwegian and English, and b) data representing different modes of discourse (spoken/written) and target audiences (adults/children) in Swedish. Of the speech error patterns, backing-the one atypical pattern of those included-was found to cause the most detrimental effects, across languages as well as across modes and speaker ages. However, none of the measures reflects intuitive rankings as provided by clinicians regarding effects on intelligibility, thus corroborating earlier reports that phonological competence is not translatable into levels of intelligibility.

Language and Learner Specific Influences on the Emergence of Consonantal Place and Manner Features

This article focuses on the emergence of consonantal place and manner feature categories in the speech of first language learners. Starting with an overview of current representational approaches to phonology, we take the position that only models that allow for the emergence of phonological categories at all levels of phonological representation (from sub-segmental properties of speech sounds all the way to word forms represented within the child's lexicon) can account for the data. We begin with a cross-linguistic survey of the acquisition of rhotic consonants. We show that the types of substitutions affecting different rhotics cross-linguistically can be predicted from two main observations: the phonetic characteristics of these rhotics and the larger system of categories displayed by each language. We then turn to a peculiar pattern of labial substitution for coronal continuants in the speech of a German learner. Building on previous literature on the topic, we attribute the emergence of this pattern to distributional properties of the child's developing lexicon. Together, these observations suggest that our understanding of phonological emergence must involve a consideration of multiple, potentially interacting levels of phonetic and phonological representation.

The Dorsal Differentiation of Velar From Alveolar Stops in Typically Developing Children and Children With Persistent Velar Fronting

Purpose This study has two key aims: first, to provide developmental articulatory norms for the alveolar-velar distinction in 30 English-speaking typically developing (TD) children; second, to illustrate the utility of the reported measures for classifying and quantifying the speech of children with a history of persistent velar fronting as they develop the contrast longitudinally. Method This study involved secondary data analysis of the UltraSuite corpus comprising ultrasound tongue imaging recordings of speech materials from 30 typical children and longitudinal data from five children with persistent velar fronting undergoing ultrasound visual biofeedback intervention. We present two new measures of coronal dorsal differentiation: KTMax and KT crescent area. These measures distinguish /k/ and /t/ by quantifying the magnitude of this distinction in absolute spatial terms (mm of linear dorsal difference). For the typical children, we report these measures in corner vowel contexts. We then compare these to dorsal productions by the children with speech disorders, before, during, and after intervention. Results Both measures reliably distinguished /k/ and /t/ in TD children. There was an effect of vowel, with larger KTmax and KT crescent area in /a/ and /o/ vowel contexts than in an /i/ context. The children with persistent velar fronting showed KTmax values near zero before intervention, showing a complete merger between /k/ and /t/. During intervention, they showed variable KTmax values. Post intervention, they showed values within the range of typical children. Conclusions This study provides articulatory norms derived from ultrasound tongue imaging for the dorsal differentiation in alveolar and velar stops in TD children. By applying these norms to children with persistent velar fronting as they acquire this contrast, we see that /k/ is acquired in an articulatorily gradient manner.

Oral Motor and Gesture Abilities Independently Associated With Preschool Language Skill: Longitudinal and Concurrent Relationships at 21 Months and 3-4 Years

Purpose Early motor abilities (gesture, oral motor, and gross/fine skills) are related to language abilities, and this is not due to an association with cognitive or symbolic abilities: Oral motor skills are uniquely associated with language abilities at 21 months of age. It is important to determine whether this motor-language relationship continues beyond the earliest stage of language development to understand language acquisition better and better predict which children may have lasting language difficulties. Method In this longitudinal study, we assessed language comprehension and production, oral motor skill, gross/fine motor skill, and meaningless manual gesture at ages 3 years (N = 89) and 4 years (N = 71), comparing the contribution of motor skill and earlier (at 21 months of age) language ability. We also examined covariates: nonverbal cognitive ability, socioeconomic status, and stimulation in the home as measured on the Home Screening Questionnaire. Results Motor abilities continue to have a significant relationship with language abilities independent of other factors in the preschool years. Meaningless manual gesture ability, gross/fine motor skill, and oral motor skill were still associated with language skill at 3 years of age; these relationships are not explained by the contribution of cognitive abilities or earlier language abilities. Conclusions Relationships between early motor skill and language development persist into preschool years and are not explained by other cognitive or home factors, nor by a relationship with earlier language ability. This finding should lead to a better understanding of the origins of language abilities.

Development and Validation of a Probe Word List to Assess Speech Motor Skills in Children

Purpose The aim of the study was to develop and validate a probe word list and scoring system to assess speech motor skills in preschool and school-age children with motor speech disorders. Method This article describes the development of a probe word list and scoring system using a modified word complexity measure and principles based on the hierarchical development of speech motor control known as the Motor Speech Hierarchy (MSH). The probe word list development accounted for factors related to word (i.e., motoric) complexity, linguistic variables, and content familiarity. The probe word list and scoring system was administered to 48 preschool and school-age children with moderate-to-severe speech motor delay at clinical centers in Ontario, Canada, and then evaluated for reliability and validity. Results One-way analyses of variance revealed that the motor complexity of the probe words increased significantly for each MSH stage, while no significant differences in the linguistic complexity were found for neighborhood density, mean biphone frequency, or log word frequency. The probe word list and scoring system yielded high reliability on measures of internal consistency and intrarater reliability. Interrater reliability indicated moderate agreement across the MSH stages, with the exception of MSH Stage V, which yielded substantial agreement. The probe word list and scoring system demonstrated high content, construct (unidimensionality, convergent validity, and discriminant validity), and criterion-related (concurrent and predictive) validity. Conclusions The probe word list and scoring system described in the current study provide a standardized method that speech-language pathologists can use in the assessment of speech motor control. It can support clinicians in identifying speech motor difficulties in preschool and school-age children, set appropriate goals, and potentially measure changes in these goals across time and/or after intervention.

Relationship between the target word form and children's productions: place of articulation in Consonant-Vowel-Consonant (C1VC2) words in American English

The aim of the present study was to investigate relationships between characteristics of children's target words and their actual productions during the single-word period in American English. Word productions in spontaneous and functional speech from 18 children acquiring American English were analyzed. Consonant sequences in 3,328 consonant-vowel-consonant (C₁VC₂) target words were analyzed in terms of global place of articulation (labials, coronals, and dorsals). Children's actual productions of place sequences were compared between target words containing repeated place sequences (e.g., mom, map, dad, not) and target words containing variegated place sequences (e.g., mat, dog, cat, nap). Overall, when the target word contained two consonants at the same global place of articulation (e.g., labial-labial, map; coronal-coronal, not), approximately 50% of children's actual productions matched consonant place characteristics. Conversely, when the target word consisted of variegated place sequences (e.g., mat, dog, cat, nap), only about 20% of the productions matched the target consonant sequences. These results suggest that children's actual productions are influenced by their own production abilities as well as by the phonetic forms of target words.

Vowel Context Effects on Consonant Repetition in Early Words

Purpose Consonant repetitions within words are a well-attested speech error pattern in children's early speech acquisition. We investigated the role of intervening vowel context in understanding speech forms containing consonant repetitions in early words. Intrasyllabic consonant-vowel (CV) sequences within consonant-vowel-consonant (CVC) and consonant-vowel-consonant-vowel (CVCV) forms containing consonant repetitions were analyzed to evaluate whether children's lack of independent movement control for the tongue in word-level sequences might contribute to these observed speech patterns. Method Spontaneous speech data produced by 10 typically developing children learning American English were analyzed longitudinally from the onset of word use to 36 months. Overall patterns and word shape effects for nine CV combinations occurring in their CVC and CVCV word shapes that contained repeated nonadjacent consonants and the intervening vowel were analyzed. Results Three CV combinations-coronal-front vowel, labial-central vowel, and dorsal-back vowel-occurred at above-chance levels. Preference for these CV patterns was strong in CVCV but not in CVC word shapes. These CV combinations occurred frequently at all time periods analyzed for CVCV's while decreasing across time for CVC's. Conclusions Analysis of intrasyllabic patterns within word forms containing consonant repetitions revealed that consonant repetitions in many early words occurred at above-chance levels in the context of articulatorily compatible vowels. Results suggest that children's production system capacities are an important contributing principle accounting for vowel context effects within word forms containing consonant repetitions during earliest speech acquisition.

Markedness and implicational relationships in phonological development: A cross-linguistic investigation

PURPOSE

The complexity approach to speech disorders, based on the theoretical notion of phonological markedness, has been gaining interest over the last decade. In a nutshell, this approach suggests that the acquisition of phonologically marked units (e.g. complex onsets) implies the acquisition of less marked ones (e.g. singleton onsets). However, because the notion of markedness is, itself, subject to controversies, we need to constrain what types of implications can be generalised among language learners, within and across languages.

METHOD

We report on longitudinal data from one phonologically-disordered and five typically-developing children documented across four different languages (English, French, German, Portuguese), using data from the PhonBank database (https://phonbank.talkbank.org). Using the Phon software program (https://www.phon.ca), we systematically analysed each longitudinal study for consonants in singleton onsets and codas as well as in onset clusters.

RESULT

The implicational relationships supported by our study involve units of similar types (e.g. relations between different segmental categories), while relationships that involve different types of units or processes cannot be generalised across learners.

CONCLUSION

A better understanding of implicational relationships makes the complexity approach more predictive of developmental patterns of phonology and related phonological disorders.

Exposure to a second language in infancy alters speech production

We evaluated the impact of exposure to a second language on infants' emerging speech production skills. We compared speech produced by three groups of 12-month-old infants while they interacted with interlocutors who spoke to them in Spanish and English: monolingual English-learning infants who had previously received 5 hours of exposure to a second language (Spanish), English- and Spanish-learning simultaneous bilinguals, and monolingual English-learning infants without any exposure to Spanish. Our results showed that the monolingual English-learning infants with short-term exposure to Spanish and the bilingual infants, but not the monolingual English-learning infants without exposure to Spanish, flexibly matched the prosody of their babbling to that of a Spanish- or English-speaking interlocutor. Our findings demonstrate the nature and extent of benefits for language learning from early exposure to two languages. We discuss the implications of these findings for language organization in infants learning two languages.

Syllable duration changes during babbling: a longitudinal study of French infant productions

At the babbling stage, the syllable does not have the temporal characteristics of adult syllables because of the infant's limited oro-motor skills. This research aims to further our knowledge of syllable duration and temporal variability and their evolution with age as an indicator of the development of articulatory skills. The possible impact of syllable position, as well as that of type of intrasyllabic associations and intersyllabic articulatory changes on these parameters has also been tested. Oral productions of 22 French infants were recorded monthly from 8 to 14 months. 11 261 Consonant-Vowel (CV) syllables were annotated and temporally analyzed. The mean duration varied according to syllable position, but not to the intrasyllabic or intersyllabic articulatory changes. Moreover, the syllable duration decreased significantly from the age of 10 months onwards, whereas the temporal variability remained the same.

A Framework of Motoric Complexity: An Investigation in Children With Typical and Impaired Speech Development

Introduction The current work presents a framework of motoric complexity where stimuli differ according to movement elements across a sound sequence (i.e., consonant transitions and vowel direction). This framework was then examined in children with childhood apraxia of speech (CAS), other speech sound disorders (SSDs), and typical development (TD). Method Twenty-four children (CAS, n = 8; SSD, n = 8; TD, n = 8), 5-6 years of age, participated in this study. The children produced words that varied in motoric complexity while transcription, acoustic, and kinematic data were collected. Multidimensional analyses were conducted to examine speech production accuracy, speech motor variability, and temporal control. Results Analyses revealed poorer accuracy, longer movement duration, and greater speech motor variability in children with CAS than TD (across all measures) and other SSDs (accuracy and variability). All children demonstrated greater speech motor variability and longer duration as movement demands increased within the framework of motoric complexity. Diagnostic grouping did not mediate performance on this task. Conclusions Results of this study are believed to reveal gradations of complexity with increasing movement demands, thereby supporting the proposed framework of motoric complexity. This work also supports the importance of considering motoric properties of sound sequences when evaluating speech production skills and designing experimental and treatment stimuli.

Assessment of prelinguistic vocalizations in real time: a comparison with phonetic transcription and assessment of inter-coder-reliability

This study investigated reliability of naturalistic listening in real time (NLRT) compared to phonetic transcription. Speech pathology students with brief training in NLRT assessed prelinguistic syllable inventory size and specific syllable types in typically developing infants. A second study also examined inter-coder reliability for canonical babbling, canonical babbling ratio and presence of oral stops in syllable inventory of infants with cleft palate, by means of NLRT. In study 1, ten students independently assessed prelinguistic samples of five 12-month-old typically developing infants using NLRT and phonetic transcription. Coders assessed syllable inventory size as more than twice as large using phonetic transcription as NLRT. Results showed a strong correlation between NLRT and phonetic transcription (syllables with more than five occurrences) for syllable inventory size (r = .60; p < .001). The methods showed similar results for inter-coder reliability of specific syllable types. In study 2, three other students assessed prelinguistic samples of twenty-eight 12-month-old infants with cleft palate by means of NLRT. Results revealed perfect inter-coder agreement for presence/absence of canonical babbling, strong correlations between the three coders' assessment of syllable inventory size (average r = .83; p < .001), but more inter-coder variability for agreement of specific syllable types. In conclusion, NLRT is a reliable method for assessing prelinguistic measures in infants with and without cleft palate with inter-coder agreement levels comparable to phonetic transcription for specific syllable types.

The Overlooked Tradition of "Personal Music" and Its Place in the Evolution of Music

This is an attempt to describe and explain so-called timbre-based music as a special system of musicking, communication, and psychological and social usage, which along with its corresponding beliefs constitutes a viable alternative to “frequency-based” music. Unfortunately, the current scientific research into music has been skewed almost entirely in favor of the frequency-based music prevalent in the West. Subsequently, whenever samples of timbre-based music attract the attention of Western researchers, these are usually interpreted as “defective” implementations of frequency-based music. The presence of discrete pitch is often regarded as the structural criterion that distinguishes music from non-music. We would like to present evidence to the contrary—in support of the existence of indigenous music systems based on the discretization and patterning of aspects of timbre, rather than pitch. This evidence comes mainly from extensive ethnographic research systematically conducted in eastern European and Asian parts of Russia from the 1890s. It involved the efforts of thousands of specialists and was coordinated by dozens of research institutions, and it has included not just ethnomusicology but linguistics, philology, organology, archaeology, anthropology, geography, and religious, and social studies. Much of the data has not been translated into Western languages. Although some Soviet-era publications were tainted by Marxist ideology, many researchers strove to provide accurate information (despite at times having been prosecuted for their work), and post-1990 research undertook a substantial revision of ideologically compromised concepts. Timbre-based tonal organization (TO) differs from that based on frequency in its personal orientation: musicking here occurs primarily for oneself and/or for close relatives/friends. Collective music-making is rare and exceptional. The foundation of timbre-based music seems to have vocal roots and rests on “personal song”—a system of personal identification through individualized patterns of rhythm, timbre, and pitch contour, utilized like a “human voice”—whose sound enables the recognition of a particular individual. The instrumental counterpart of the personalized singing tradition is the jaw harp tradition. The jaw harp is the principal musical instrument for at least 21 ethnicities in Russia, who occupy over half the territory of the country. The evolution of its TO forms the backbone for the development of timbre-based music art. Here, we provide the acoustic, socio-cultural, geographic, and chronological overview of timbre-based music.

Speech Sound Disorders in Children: An Articulatory Phonology Perspective

Speech Sound Disorders (SSDs) is a generic term used to describe a range of difficulties producing speech sounds in children (McLeod and Baker, 2017). The foundations of clinical assessment, classification and intervention for children with SSD have been heavily influenced by psycholinguistic theory and procedures, which largely posit a firm boundary between phonological processes and phonetics/articulation (Shriberg, 2010). Thus, in many current SSD classification systems the complex relationships between the etiology (distal), processing deficits (proximal) and the behavioral levels (speech symptoms) is under-specified (Terband et al., 2019a). It is critical to understand the complex interactions between these levels as they have implications for differential diagnosis and treatment planning (Terband et al., 2019a). There have been some theoretical attempts made towards understanding these interactions (e.g., McAllister Byun and Tessier, 2016) and characterizing speech patterns in children either solely as the product of speech motor performance limitations or purely as a consequence of phonological/grammatical competence has been challenged (Inkelas and Rose, 2007; McAllister Byun, 2012). In the present paper, we intend to reconcile the phonetic-phonology dichotomy and discuss the interconnectedness between these levels and the nature of SSDs using an alternative perspective based on the notion of an articulatory "gesture" within the broader concepts of the Articulatory Phonology model (AP; Browman and Goldstein, 1992). The articulatory "gesture" serves as a unit of phonological contrast and characterization of the resulting articulatory movements (Browman and Goldstein, 1992; van Lieshout and Goldstein, 2008). We present evidence supporting the notion of articulatory gestures at the level of speech production and as reflected in control processes in the brain and discuss how an articulatory "gesture"-based approach can account for articulatory behaviors in typical and disordered speech production (van Lieshout, 2004; Pouplier and van Lieshout, 2016). Specifically, we discuss how the AP model can provide an explanatory framework for understanding SSDs in children. Although other theories may be able to provide alternate explanations for some of the issues we will discuss, the AP framework in our view generates a unique scope that covers linguistic (phonology) and motor processes in a unified manner.

Sequence and hierarchy in vocal rhythms and phonology

I explore the neural and evolutionary origins of phonological hierarchy, building on Peter MacNeilage's frame/content model, which suggests that human speech evolved from primate nonvocal jaw oscillations, for example, lip smack displays, combined with phonation. Considerable recent data, reviewed here, support this proposition. I argue that the evolution of speech motor control required two independent components. The first, identified by MacNeilage, is the diversification of phonetic "content" within a simple sequential "frame," and would be within reach of nonhuman primates, by simply intermittently activating phonation during lip smack displays. Such voicing control requires laryngeal control, hypothesized to necessitate direct corticomotor connections to the nucleus ambiguus. The second component, proposed here, involves imposing additional hierarchical rhythmic structure upon the "flat" control sequences typifying mammalian vocal tract oscillations and is required for the flexible combinatorial capacity observed in modern phonology. I hypothesize that phonological hierarchy resulted from a marriage of a preexisting capacity for sequential structure seen in other primates, with novel hierarchical motor control circuitry (potentially evolved in tool use and/or musical contexts). In turn, this phonological hierarchy paved the way for phrasal syntactic hierarchy. I support these arguments using comparative and neural data from nonhuman primates and birdsong.

Volubility, Consonant Emergence, and Syllabic Structure in Infants and Toddlers Later Diagnosed With Childhood Apraxia of Speech, Speech Sound Disorder, and Typical Development: A Retrospective Video Analysis

Purpose Studies of infants' early vocalizations have proven helpful in describing the developmental characteristics of various communication disorders. However, few studies have addressed the early vocalizations of infants and toddlers who were later diagnosed, as older children, with childhood apraxia of speech (CAS). We refer to these infants and toddlers as LCAS. Extant studies also often lack a comparison group of infants and toddlers who were later diagnosed, as older children, with a speech sound disorder (SSD). We refer to these infants and toddlers as LSSD. We aimed to compare the volubility, consonant emergence, and syllabic structure from birth to age of 2 years, as observed in home videos, among 3 groups of infants and toddlers: LCAS, LSSD, and typically developing (TD). Method We assessed the speech-language skills of 17 children (3.5-8.8 years old; 7 with CAS, 5 with SSD, and 5 TD) and transcribed home videos (obtained from parents) of these same children from birth to age of 2 years. Early vocalizations were coded as nonresonant or resonant. Nonresonant vocalizations could not be transcribed with the International Phonetic Alphabet. Resonant (speechlike) vocalizations were broadly transcribed, and resonant consonants were categorized by place, manner, and voicing. Results Effect size comparisons revealed LCAS infants and toddlers were less voluble, used fewer resonant consonants, had a less diverse phonetic repertoire, and acquired resonant consonants later than either the LSSD or TD participants. For LSSD infants and toddlers, means for these dependent variables were lower than the means demonstrated by the TD group, but effect size were not strong due to LSSD variability. Conclusions Findings imply there might be clinical "red flags" that could assist the identification of infants and toddlers at risk for later diagnosis of CAS. Data did not support red flags for identifying infants and toddlers at risk for later diagnosis of SSD. Because of significant study limitations, results obtained should be considered preliminary. Supplemental Material https://doi.org/10.23641/asha.8233334.

Vocal production and novel word learning in the first year

Previous studies have demonstrated an effect of early vocal production on infants' speech processing and later vocabulary. This study focuses on the relationship between vocal production and new word learning. Thirty monolingual Italian-learning infants were recorded at about 11 months, to establish the extent of their consonant production. In parallel, the infants were trained on novel word-object pairs, two consisting of early learned consonants (ELC), two consisting of late learned consonants (LLC). Word learning was assessed through Preferential Looking. The results suggest that vocal production supports word learning: Only children with higher, consistent consonant production attended more to the trained ELC images.

Questioning the role of lexical contrastiveness in phonological development: Converging evidence from perception and production studies

In this article, we address relations between lexical and phonological development, with an emphasis on the notion of phonological contrast. We begin with an overview of the literature on word learning and on infant speech perception. Among other results, we report on studies showing that toddlers' perceptual abilities do not correlate with the development of phonological contrasts within their lexicons. We then engage in a systematic comparison between the lexical development of two child learners of English and their acquisition of consonants in syllable onsets. We establish a developmental timeline for each child's onset consonant system, which we compare to the types of phonological contrasts that are present in their expressive vocabularies at each relevant milestone. Like the earlier studies, ours also fails to return tangible parallels between the two areas of development. The data instead suggest that patterns of phonological development are best described in terms of the segmental categories they involve, in relative independence from measures of contrastiveness within the learners' lexicons.

Early Motor and Communicative Development in Infants With an Older Sibling With Autism Spectrum Disorder

Purpose

A recent approach to identifying early markers of risk for autism spectrum disorder (ASD) has been to study infants who have an older sibling with ASD. These infants are at heightened risk (HR) for ASD and for other developmental difficulties, and even those who do not receive an eventual ASD diagnosis manifest a high degree of variability in trajectories of development. The primary goal of this review is to summarize findings from research on early motor and communicative development in these HR infants.

Method

This review focuses on 2 lines of inquiry. The first assesses whether delays and atypicalities in early motor abilities and in the development of early communication provide an index of eventual ASD diagnosis. The second asks whether such delays also influence infants' interactions with objects and people in ways that exert far-reaching, cascading effects on development.

Results

HR infants who do and who do not receive a diagnosis of ASD vary widely in motor and communicative development. In addition, variation in infant motor and communicative development appears to have cascading effects on development, both on the emergence of behavior in other domains and on the broader learning environment.

Conclusions

Advances in communicative and language development are supported by advances in motor skill. When these advances are slowed and/or when new skills are not consolidated and remain challenging for the infant, the enhanced potential for exploration afforded by new abilities and the concomitant increase in opportunities for learning are reduced. Improving our understanding of communicative delays of the sort observed in ASD and developing effective intervention methods requires going beyond the individual to consider the constant, complex interplay between developing communicators and their environments.

Presentation Video

https://doi.org/10.23641/asha.7299308.

Behavioral predictors of improved speech output in minimally verbal children with autism

We investigated the relationship between eight theoretically motivated behavioral variables and a spoken-language-related outcome measure, after 25 sessions of treatment for speech production in 38 minimally verbal children with autism. After removing potential predictors that were uncorrelated with the outcome variable, two remained. We used both complete-case and multiple-imputation analyses to address missing predictor data and performed linear regressions to identify significant predictors of change in percent syllables approximately correct after treatment. Baseline phonetic inventory (the number of English phonemes repeated correctly) was the most robust predictor of improvement. In the group of 17 participants with complete data, ADOS score also significantly predicted the outcome. In contrast to some earlier studies, nonverbal IQ, baseline levels of expressive language, and younger age did not significantly predict improvement. The present results are not only consistent with previous studies showing that verbal imitation and autism severity significantly predict spoken language outcomes in preschool-aged minimally verbal children with autism, but also extend these findings to older minimally verbal children with autism. Autism Res 2018, 11: 1356-1365. © 2018 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: We wished to understand what baseline factors predicted whether minimally verbal children with autism would improve after treatment for spoken language. The outcome measure was change in percentage (%) syllables approximately correct on a set of 30 two-syllable words or phrases. Fifteen were both practiced in treatment and tested; the remainder were not practiced in treatment, but only tested, to assess how well children were able to generalize their new skills to an untrained set of words. Potential predictors tested were sex, age, expressive language, phonetic inventory (the number of English speech sounds repeated correctly), autism severity, and nonverbal IQ. Phonetic inventory and (for some children) autism severity predicted children's posttreatment improvement. Nonverbal IQ and expressive language ability did not predict improvement, nor did younger age, suggesting that some older children with autism may be candidates for speech therapy.

From intuition to intervention: developing an intonation-based treatment for autism

Autism affects ∼1.5% of children under age 8; its core symptoms include impairment in social-communicative functioning and repetitive behaviors/restricted interests. Music-based interventions have been considered one modality through which to treat autism. This report discusses considerations to take into account when developing a music-based intervention for a core symptom of autism. Treatment modality must be matched to symptom both clinically and theoretically, the behavior to be treated must be carefully defined and assessed, and outcome measures must be capable of showing improvement in that behavior over the course of the study. Fidelity assessment and rater blinding reduce experimenter bias. High inter-rater reliability for perceptually determined outcome measures helps obtain accurate estimates of treatment response. Later stages of testing compare the experimental intervention to matched control treatments or other validated therapies, isolating the intervention's "active ingredients." Such systematic investigation of a new music-based intervention can provide information of different types, ranging from an assessment of whether the intervention has any effect at all to an assessment of its outcomes and risks in uncontrolled community settings. Findings ultimately compose the evidence base that clinicians and families can use to decide the most effective way of addressing symptoms of autism for particular children.

A Review of Phonological Development of Mandarin-Speaking Children

PURPOSE

Research into the phonological development of Chinese children is in its infancy compared with the relatively extensive data available on the English-speaking population. This article provided a comprehensive review of empirical studies on the acquisition of Mandarin phonology.

METHOD

Studies over the past 45 years that describe phonological development in Mandarin-speaking children were located through electronic databases, citation searches, keyword searches through online search engines, and manual searches of libraries. The research design of the studies was reviewed, and findings of acceptable studies were summarized.

RESULTS

After reviewing the abstracts of 798 studies, a total of 12 that met the inclusion criteria were retained. These studies are discussed with reference to the demographic background of participants, geographic regions, aspects of speech sounds measured, data collection tools, transcription systems used, reliability, and the main findings.

CONCLUSIONS

The general developmental patterns reported were consistent. The methodological design varied substantially. These discrepancies, however, provide insights for further systematic investigations into phonological development in Mandarin.

Methods for eliciting, annotating, and analyzing databases for child speech development

Methods from automatic speech recognition (ASR), such as segmentation and forced alignment, have facilitated the rapid annotation and analysis of very large adult speech databases and databases of caregiver-infant interaction, enabling advances in speech science that were unimaginable just a few decades ago. This paper centers on two main problems that must be addressed in order to have analogous resources for developing and exploiting databases of young children's speech. The first problem is to understand and appreciate the differences between adult and child speech that cause ASR models developed for adult speech to fail when applied to child speech. These differences include the fact that children's vocal tracts are smaller than those of adult males and also changing rapidly in size and shape over the course of development, leading to between-talker variability across age groups that dwarfs the between-talker differences between adult men and women. Moreover, children do not achieve fully adult-like speech motor control until they are young adults, and their vocabularies and phonological proficiency are developing as well, leading to considerably more within-talker variability as well as more between-talker variability. The second problem then is to determine what annotation schemas and analysis techniques can most usefully capture relevant aspects of this variability. Indeed, standard acoustic characterizations applied to child speech reveal that adult-centered annotation schemas fail to capture phenomena such as the emergence of covert contrasts in children's developing phonological systems, while also revealing children's nonuniform progression toward community speech norms as they acquire the phonological systems of their native languages. Both problems point to the need for more basic research into the growth and development of the articulatory system (as well as of the lexicon and phonological system) that is oriented explicitly toward the construction of age-appropriate computational models.

Auditory-Motor Mapping Training in a More Verbal Child with Autism

We tested the effect of Auditory-Motor Mapping Training (AMMT), a novel, intonation-based treatment for spoken language originally developed for minimally verbal (MV) children with autism, on a more-verbal child with autism. We compared this child’s performance after 25 therapy sessions with that of: (1) a child matched on age, autism severity, and expressive language level who received 25 sessions of a non-intonation-based control treatment Speech Repetition Therapy (SRT); and (2) a matched pair of MV children (one of whom received AMMT; the other, SRT). We found a significant Time × Treatment effect in favor of AMMT for number of Syllables Correct and Consonants Correct per stimulus for both pairs of children, as well as a significant Time × Treatment effect in favor of AMMT for number of Vowels Correct per stimulus for the more-verbal pair. Magnitudes of the difference in post-treatment performance between AMMT and SRT, adjusted for Baseline differences, were: (a) larger for the more-verbal pair than for the MV pair; and (b) associated with very large effect sizes (Cohen’s d > 1.3) in the more-verbal pair. Results hold promise for the efficacy of AMMT for improving spoken language production in more-verbal children with autism as well as their MV peers and suggest hypotheses about brain function that are testable in both correlational and causal behavioral-imaging studies.

Non-adjacent consonant sequence patterns in English target words during the first-word period

The goal of this study was to investigate non-adjacent consonant sequence patterns in target words during the first-word period in infants learning American English. In the spontaneous speech of eighteen participants, target words with a Consonant-Vowel-Consonant (C1VC2) shape were analyzed. Target words were grouped into nine types, categorized by place of articulation (labial, coronal, dorsal) of initial and final consonants (e.g. mom, labial-labial; mat, labial-coronal; dog, coronal-dorsal). The results indicated that some consonant sequences occurred much more frequently than others in early target words. The two most frequent types were coronal-coronal (e.g. dad) and labial-coronal (e.g. mat). The least frequent type was dorsal-dorsal (e.g. cake). These patterns are consistent with phonotactic characteristics of English and infants' production capacities reported in previous studies. This study demonstrates that infants' expressive vocabularies reflect both ambient language characteristics and their own production capacities, at least for consonant sequences in C1VC2 word forms.

Profiles of vocal development in Korean children with and without cleft palate

This study longitudinally investigated vocal development in Korean children from 9 to 18 months of age with and without cleft palate (CP). Utterance samples were collected from 24 children with and without CP at 9, 12, 15 and 18 months of age. Each utterance was categorised into levels of vocalisation using the Korean-translated version of the Stark Assessment of Early Vocal Development-Revised (SAEVD-R). The results showed children with CP produced a significantly higher rate of precanonical vocalisations (the combination of Levels 1, 2, and 3) and a lower rate of Level 4 and 5 vocalisations than children without CP. Both groups showed decreases in Levels 1 and 2 and increases in Level 5 from 9 to 18 months of age. A significant increase in the proportion of Level 4 vocalisations across age was observed only in children without CP. Young Korean children with CP showed lower proportions of advanced vocalisation levels characterised by canonical and complex syllable structures across 9 and 18 months of age compared to children without CP.

White Matter Integrity and Treatment-Based Change in Speech Performance in Minimally Verbal Children with Autism Spectrum Disorder

We investigated the relationship between imaging variables for two language/speech-motor tracts and speech fluency variables in 10 minimally verbal (MV) children with autism. Specifically, we tested whether measures of white matter integrity—fractional anisotropy (FA) of the arcuate fasciculus (AF) and frontal aslant tract (FAT)—were related to change in percent syllable-initial consonants correct, percent items responded to, and percent syllable insertion errors (from best baseline to post 25 treatment sessions). Twenty-three MV children with autism spectrum disorder (ASD) received Auditory-Motor Mapping Training (AMMT), an intonation-based treatment to improve fluency in spoken output, and we report on seven who received a matched control treatment. Ten of the AMMT participants were able to undergo a magnetic resonance imaging study at baseline; their performance on baseline speech production measures is compared to that of the other two groups. No baseline differences were found between groups. A canonical correlation analysis (CCA) relating FA values for left- and right-hemisphere AF and FAT to speech production measures showed that FA of the left AF and right FAT were the largest contributors to the synthetic independent imaging-related variable. Change in percent syllable-initial consonants correct and percent syllable-insertion errors were the largest contributors to the synthetic dependent fluency-related variable. Regression analyses showed that FA values in left AF significantly predicted change in percent syllable-initial consonants correct, no FA variables significantly predicted change in percent items responded to, and FA of right FAT significantly predicted change in percent syllable-insertion errors. Results are consistent with previously identified roles for the AF in mediating bidirectional mapping between articulation and acoustics, and the FAT in its relationship to speech initiation and fluency. They further suggest a division of labor between the hemispheres, implicating the left hemisphere in accuracy of speech production and the right hemisphere in fluency in this population. Changes in response rate are interpreted as stemming from factors other than the integrity of these two fiber tracts. This study is the first to document the existence of a subgroup of MV children who experience increases in syllable- insertion errors as their speech develops in response to therapy.

Acquisition of voice onset time in toddlers at high and low risk for autism spectrum disorder

Although language delay is common in autism spectrum disorder (ASD), research is equivocal on whether speech development is affected. We used acoustic methods to investigate the existence of sub-perceptual differences in the speech of toddlers who developed ASD. Development of the distinction between b and p was prospectively tracked in 22 toddlers at low risk for ASD (LRC), 22 at high risk for ASD without ASD (HRA-), and 11 at high risk for ASD who were diagnosed with ASD at 36 months (HRA+). Voice onset time (VOT), the main acoustic difference between b and p, was measured from spontaneously produced words at 18, 24, and 36 months. Number of words, number of tokens (instances) of syllable-initial b and p produced, error rates, language scores, and motor ability were also assessed. All groups' mean language scores were within the average range or slightly higher. No between-group differences were found in number of words, b's, p's, or errors produced; or in mean or standard deviation of VOT. Binary logistic regression showed that only diagnostic status, not language score, motor ability, number of words, number of b's and p's, or number of errors significantly predicted whether a toddler produced acoustically distinct b and p populations at 36 months. HRA+ toddlers were significantly less likely to produce acoustically distinct b's and p's at 36 months, which may indicate that the HRA+ group may be using different strategies to produce this distinction. Autism Res 2017. © 2017 International Society for Autism Research, Wiley Periodicals, Inc. Autism Res 2017, 10: 1269-1279. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.

Imitation of Non-Speech Oral Gestures by 8-Month-Old Infants

This study investigates the oral gestures of 8-month-old infants in response to audiovisual presentation of lip and tongue smacks. Infants exhibited more lip gestures than tongue gestures following adult lip smacks and more tongue gestures than lip gestures following adult tongue smacks. The findings, which are consistent with predictions from Articulatory Phonology, imply that 8-month-old infants are capable of producing goal-directed oral gestures by matching the articulatory organ of an adult model.

Auditory-Motor Mapping Training: Comparing the Effects of a Novel Speech Treatment to a Control Treatment for Minimally Verbal Children with Autism

This study compared Auditory-Motor Mapping Training (AMMT), an intonation-based treatment for facilitating spoken language in minimally verbal children with autism spectrum disorder (ASD), to a matched control treatment, Speech Repetition Therapy (SRT). 23 minimally verbal children with ASD (20 male, mean age 6;5) received at least 25 sessions of AMMT. Seven (all male) were matched on age and verbal ability to seven participants (five male) who received SRT. Outcome measures were Percent Syllables Approximated, Percent Consonants Correct (of 86), and Percent Vowels Correct (of 61) produced on two sets of 15 bisyllabic stimuli. All subjects were assessed on these measures several times at baseline and after 10, 15, 20, and 25 sessions. The post-25 session assessment timepoint, common to all participants, was compared to Best Baseline performance. Overall, after 25 sessions, AMMT participants increased by 19.4% Syllables Approximated, 13.8% Consonants Correct, and19.1% Vowels Correct, compared to Best Baseline. In the matched AMMT-SRT group, after 25 sessions, AMMT participants produced 29.0% more Syllables Approximated (SRT 3.6%);17.9% more Consonants Correct (SRT 0.5); and 17.6% more Vowels Correct (SRT 0.8%). Chi-square tests showed that significantly more AMMT than SRT participants in both the overall and matched groups improved significantly in number of Syllables Approximated per stimulus and number of Consonants Correct per stimulus. Pre-treatment ability to imitate phonemes, but not chronological age or baseline performance on outcome measures, was significantly correlated with amount of improvement after 25 sessions. Intonation-based therapy may offer a promising new interventional approach for teaching spoken language to minimally verbal children with ASD.

Articulating What Infants Attune to in Native Speech

To become language users, infants must embrace the integrality of speech perception and production. That they do so, and quite rapidly, is implied by the native-language attunement they achieve in each domain by 6-12 months. Yet research has most often addressed one or the other domain, rarely how they interrelate. Moreover, mainstream assumptions that perception relies on acoustic patterns whereas production involves motor patterns entail that the infant would have to translate incommensurable information to grasp the perception-production relationship. We posit the more parsimonious view that both domains depend on commensurate articulatory information. Our proposed framework combines principles of the Perceptual Assimilation Model (PAM) and Articulatory Phonology (AP). According to PAM, infants attune to articulatory information in native speech and detect similarities of nonnative phones to native articulatory patterns. The AP premise that gestures of the speech organs are the basic elements of phonology offers articulatory similarity metrics while satisfying the requirement that phonological information be discrete and contrastive: (a) distinct articulatory organs produce vocal tract constrictions and (b) phonological contrasts recruit different articulators and/or constrictions of a given articulator that differ in degree or location. Various lines of research suggest young children perceive articulatory information, which guides their productions: discrimination of between- versus within-organ contrasts, simulations of attunement to language-specific articulatory distributions, multimodal speech perception, oral/vocal imitation, and perceptual effects of articulator activation or suppression. We conclude that articulatory gesture information serves as the foundation for developmental integrality of speech perception and production.

Vowels Development in Babbling of typically developing 6-to-12-month old Persian-learning Infants

OBJECTIVES

Pre-linguistic vocalizations including early consonants, vowels, and their combinations into syllables are considered as important predictors of the speech and language development. The purpose of this study was to examine vowel development in babblings of normally developing Persian-learning infants.

METHODS

Eight typically developing 6-8-month-old Persian-learning infants (3 boys and 5 girls) participated in this 4-month longitudinal descriptive-analytic study. A weekly 30-60-minute audio- and video-recording was obtained at home from the comfort state vocalizations of infants and the mother-child interactions. A total of 74:02:03 hours of vocalizations were phonetically transcribed. Seven vowels comprising /i/,/e/,/a/,/u/,/o/,/ɑ/, and /ә/ were identified in the babblings. The inter-rater reliability was obtained for 20% of vocalizations. The data were analyzed by repeated measures ANOVA and Pearson's correlation coefficient using SPSS software version 20.

RESULTS

The results showed that two vowels /a/ (46.04) and /e/ (23.60) were produced with the highest mean frequency of occurrence, respectively. Regarding front/back dimension, the front vowels were the most prominent ones (71.87); in terms of height, low (46.78) and mid (32.45) vowels occurred maximally. A good inter-rater reliability was obtained (0.99, P < .01).

CONCLUSION

The increased frequency of occurrence of the low and mid front vowels in the current study was consistent with previous studies on the emergence of vowels in pre-linguistic vocalization in other languages.

Learning words and learning sounds: Advances in language development

Phonological development is sometimes seen as a process of learning sounds, or forming phonological categories, and then combining sounds to build words, with the evidence taken largely from studies demonstrating 'perceptual narrowing' in infant speech perception over the first year of life. In contrast, studies of early word production have long provided evidence that holistic word learning may precede the formation of phonological categories. In that account, children begin by matching their existing vocal patterns to adult words, with knowledge of the phonological system emerging from the network of related word forms. Here I review evidence from production and then consider how the implicit and explicit learning mechanisms assumed by the complementary memory systems model might be understood as reconciling the two approaches.

Making Sense of Infant Familiarity and Novelty Responses to Words at Lexical Onset

This study suggests that familiarity and novelty preferences in infant experimental tasks can in some instances be interpreted together as a single indicator of language advance. We provide evidence to support this idea based on our use of the auditory headturn preference paradigm to record responses to words likely to be either familiar or unfamiliar to infants. Fifty-nine 10-month-old infants were tested. The task elicited mixed preferences: familiarity (longer average looks to the words likely to be familiar to the infants), novelty (longer average looks to the words likely to be unfamiliar) and no-preference (similar-length of looks to both type of words). The infants who exhibited either a familiarity or a novelty response were more advanced on independent indices of phonetic advance than the infants who showed no preference. In addition, infants exhibiting novelty responses were more lexically advanced than either the infants who exhibited familiarity or those who showed no-preference. The results provide partial support for Hunter and Ames' (1988) developmental model of attention in infancy and suggest caution when interpreting studies indexed to chronological age.

Baby babbling at five months linked to sex hormone levels in early infancy

Gender-dependent differentiation of the brain at morphological, neurochemical and functional levels of organization have been shown to be primarily controlled by sex differences in gonadal hormone concentrations during pre- and early postnatal development. Indeed, previous studies have reported that pre- and perinatal hormonal environments influence brain development and, consequently, affect sex specific long-term language outcomes. Herein, we investigated whether postnatal surges of estrogen (estradiol) and androgen (testosterone) may predict properties of pre-speech babbling at five months. This study is the first attempt to investigate a possible correlation between sex hormones and infants' articulatory skills during the typical postnatal period of extended hormonal activity known as 'mini-puberty.' A hierarchical, multiple regression approach revealed a significant, robust positive relationship between 4-week concentrations of estradiol and individual articulatory skills. In contrast, testosterone concentrations at five months negatively correlated with articulatory skills at the same age in both boys and girls. Our findings reinforce the assumption of the importance of sex hormones for auditory-vocal development towards language in human infants.

Structure and variability in human tongue muscle anatomy

The human tongue has a complex architecture, consistent with its complex roles in eating, speaking and breathing. Tongue muscle architecture has been depicted in drawings and photographs, but not quantified volumetrically. This paper aims to fill that gap by measuring the muscle architecture of the tongue for 14 people captured in high-resolution 3D MRI volumes. The results show the structure, relationships and variability among the muscles, as well as the effects of age, gender and weight on muscle volume. Since the tongue consists of partially interdigitated muscles, we consider the muscle volumes in two ways. The functional muscle volume encompasses the region of the tongue served by the muscle. The structural volume halves the volume of the muscle in regions where it interdigitates with other muscles. Results show similarity of scaling across subjects, and speculate on functional effects of the anatomical structure.

Design and Validation of a Talking Face for the iCub

Recent developments in human–robot interaction show how the ability to communicate with people in a natural way is of great importance for artificial agents. The implementation of facial expressions has been found to significantly increase the interaction capabilities of humanoid robots. For speech, displaying a correct articulation with sound is mandatory to avoid audiovisual illusions like the McGurk effect (leading to comprehension errors) as well as to enhance the intelligibility in noisy conditions. This work describes the design, construction and testing of an animatronic talking face developed for the iCub robot. This talking head has an articulated jaw and four independent lip movements actuated by five motors. It is covered by a specially designed elastic tissue cover whose hemlines at the lips are attached to the motors via connecting linkages. The mechanical design and the control scheme have been evaluated by speech intelligibility in noise (SPIN) perceptual tests that demonstrate an absolute 10% intelligibility gain provided by the jaw and lip movements over the audio-only display.

Non-verbal sensorimotor timing deficits in children and adolescents who stutter

There is growing evidence that motor and speech disorders co-occur during development. In the present study, we investigated whether stuttering, a developmental speech disorder, is associated with a predictive timing deficit in childhood and adolescence. By testing sensorimotor synchronization abilities, we aimed to assess whether predictive timing is dysfunctional in young participants who stutter (8-16 years). Twenty German children and adolescents who stutter and 43 non-stuttering participants matched for age and musical training were tested on their ability to synchronize their finger taps with periodic tone sequences and with a musical beat. Forty percent of children and 90% of adolescents who stutter displayed poor synchronization with both metronome and musical stimuli, falling below 2.5% of the estimated population based on the performance of the group without the disorder. Synchronization deficits were characterized by either lower synchronization accuracy or lower consistency or both. Lower accuracy resulted in an over-anticipation of the pacing event in participants who stutter. Moreover, individual profiles revealed that lower consistency was typical of participants that were severely stuttering. These findings support the idea that malfunctioning predictive timing during auditory-motor coupling plays a role in stuttering in children and adolescents.