Susan Rvachew

The impact of early onset otitis media on babbling and early language development

Numerous studies have shown that otitis media (OM) during infancy has a negative impact on language development later in life. Few studies have examined the effect of OM on linguistic and prelinguistic behavior during infancy. The purpose of this study was to investigate the impact of OM on the development of canonical babble in children who experienced at least one episode during the period birth through 6 months of age, in comparison with children who did not experience OM during this period. The results show a consistently lower rate of canonical syllable production among children with early onset OM, when compared to children with later onset OM, during the period 6 through 18 months of age. In addition, a relationship between canonical babbling ability and expressive vocabulary size was observed at 18 months of age.

Developmental and cross-linguistic variation in the infant vowel space: The case of Canadian English and Canadian French

This article describes the results of two experiments. Experiment 1 was a cross-sectional study designed to explore developmental and cross-linguistic variation in the vowel space of 10- to 18-month-old infants, exposed to either Canadian English or Canadian French. Acoustic parameters of the infant vowel space were described (specifically the mean and standard deviation of the first and second formant frequencies) and then used to derive the grave, acute, compact, and diffuse features of the vowel space across age. A decline in mean F1 with age for French-learning infants and a decline in mean F2 with age for English-learning infants was observed. A developmental expansion of the vowel space into the high-front and high-back regions was also evident. In experiment 2, the Variable Linear Articulatory Model was used to model the infant vowel space taking into consideration vocal tract size and morphology. Two simulations were performed, one with full range of movement for all articulatory paramenters, and the other for movement of jaw and lip parameters only. These simulated vowel spaces were used to aid in the interpretation of the developmental changes and cross-linguistic influences on vowel production in experiment 1.

Speech Perception by 6- to 8-Month-Olds in the Presence of Distracting Sounds

The role of selective attention in infant phonetic perception was examined using a distraction masker paradigm. We compared perception of /bu/ versus /gu/ in 6- to 8-month-olds using a visual fixat...

Auditory-Motor Learning during Speech Production in 9-11-Year-Old Children

Background Hearing ability is essential for normal speech development, however the precise mechanisms linking auditory input and the improvement of speaking ability remain poorly understood. Auditory feedback during speech production is believed to play a critical role by providing the nervous system with information about speech outcomes that is used to learn and subsequently fine-tune speech motor output. Surprisingly, few studies have directly investigated such auditory-motor learning in the speech production of typically developing children. Methodology/Principal Findings In the present study, we manipulated auditory feedback during speech production in a group of 9–11-year old children, as well as in adults. Following a period of speech practice under conditions of altered auditory feedback, compensatory changes in speech production and perception were examined. Consistent with prior studies, the adults exhibited compensatory changes in both their speech motor output and their perceptual representations of speech sound categories. The children exhibited compensatory changes in the motor domain, with a change in speech output that was similar in magnitude to that of the adults, however the children showed no reliable compensatory effect on their perceptual representations. Conclusions The results indicate that 9–11-year-old children, whose speech motor and perceptual abilities are still not fully developed, are nonetheless capable of auditory-feedback-based sensorimotor adaptation, supporting a role for such learning processes in speech motor development. Auditory feedback may play a more limited role, however, in the fine-tuning of childrens perceptual representations of speech sound categories.

Vocal Development of Infants with Very Low Birth Weight.

This study describes the vocal development of infants born with very low birth weights (VLBW). Samples of vocalizations were recorded from three groups of infants when they were 8, 12 and 18 months of age: preterm VLBW infants with bronchopulmonary dysplasia (BPD), preterm VLBW infants without BPD, and healthy full‐term infants. Infants with BPD produced significantly smaller canonical syllable ratios than the full‐term infants throughout the period of study. Premature VLBW infants who did not suffer from BPD produced relatively little canonical babble at 8 months of age, but were performing within the range of the full‐term infants at 18 months of age. At 18 months of age, the infants with BPD were reported to have significantly smaller expressive vocabulary sizes than the healthier preterm and full‐term infants.

The influence of syllable position on children's production of consonants

Two studies examined consonant production by 13 children with delayed phonological skills. Study 1 examined patterns of substitution errors in word-initial, word-final and intervocalic positions of two-syllable words with a strong-weak stress pattern. For phonemes that were misarticulated in at least one word position, intervocalic consonant production was most likely to be the same as the word-final consonant production, but different from the word-initial consonant production. Study 2 examined proportions of matches and mismatches for features in five positions of multisyllabic words: (1) syllable-initial, word-initial, (2) syllable-initial, within-word, (3) intervocalic before an unstressed syllable, (4) syllable-final, within-word, and (5) syllable-final, word-final. Significant variations in match ratios were observed as a function of syllable position. A number of different patterns of position-dependent errors were observed.

Emergence of the corner vowels in the babble produced by infants exposed to Canadian English or Canadian French.

This paper examined the emergence of corner vowels ([i], [u], [ae] and [a]) in the infant vowel spaces and the influence of the ambient language on babbling, in particular, on the frequency of occurrence of the corner vowels. Speech samples were recorded from 51 Canadian infants from 8 to 18 months of age, respectively, English-learning infants (n=24) and French-learning infants (n=27). The acoustic parameters (F1 and F2) of each codable infant vowel were analyzed and then used to plot all the vowels along the diffuse–compact (F2−F1) and grave–acute dimensions ([F1+F2]/2). Listener judgments of vowel category were obtained for the most extreme vowels in each infants vowel space, i.e., the 10% vowels with minimum or maximum diffuse–compact and grave–acute values. The judgments of adult listeners, both anglophone (n=5) and francophone (n=5), confirmed the peripheral expansion of infant vowel space toward the diffuse and grave corners with age. Furthermore, English-learning infants were judged by both English and French-speaking listeners to produce a greater frequency of [u] in the grave corner, in comparison with French-learning infants. The higher proportion of [u] in English sample was observed throughout the age range suggesting the influence of ambient language at a young age.

Monolingual or Bilingual Intervention for Primary Language Impairment? A Randomized Control Trial

PURPOSE This study investigated the clinical effectiveness of monolingual versus bilingual language intervention, the latter involving speech-language pathologist-parent collaboration. The study focuses on methods that are currently being recommended and that are feasible within current clinical contexts. METHOD Bilingual children with primary language impairment who speak a minority language as their home language and French as their second (n=29, mean age=5 years) were randomly assigned to monolingual treatment, bilingual treatment, and no-treatment (delayed-treatment) conditions. Sixteen sessions of individual language intervention were offered, targeting vocabulary and syntactic skills in French only or bilingually, through parent collaboration during the clinical sessions. Language evaluations were conducted before and after treatment by blinded examiners; these evaluations targeted French as well as the home languages. An additional evaluation was conducted 2 months after completion of treatment to assess maintenance of gains. Both monolingual and bilingual treatment followed a focused stimulation approach. RESULTS Results in French showed a significant treatment effect for vocabulary but no difference between treatment conditions. Gains were made in syntax, but these gains could not be attributed to treatment given that treatment groups did not improve more than the control group. Home language probes did not suggest that the therapy had resulted in gains in the home language. CONCLUSIONS The intervention used in this study is in line with current recommendations of major speech-language pathology organizations. However, the findings indicate that the bilingual treatment created through collaboration with parents was not effective in creating a sufficiently intense bilingual context to make it significantly different from the monolingual treatment. Further studies are needed to assess the gains associated with clinical modifications made for bilingual children and to search for effective ways to accommodate their unique needs.

A Longitudinal Investigation of Morpho-Syntax in Children with Speech Sound Disorders.

PURPOSE The intent of this study was to examine the longitudinal morpho-syntactic progression of children with Speech Sound Disorders (SSD) grouped according to Mean Length of Utterance (MLU) scores. METHODS Thirty-seven children separated into four clusters were assessed in their pre-kindergarten and Grade 1 years. Cluster 1 were children with typical development; the other clusters were children with SSD. Cluster 2 had good pre-kindergarten MLU; Clusters 3 and 4 had low MLU scores in pre-kindergarten, and (respectively) good and poor MLU outcomes. RESULTS Children with SSD in pre-kindergarten had lower Developmental Sentence Scores (DSS) and made fewer attempts at finite embedded clauses than children with typical development. All children with SSD, especially Cluster 4, had difficulty with finite verb morphology. CONCLUSIONS Children with SSD and typical MLU may be weak in some areas of syntax. Children with SSD who have low MLU scores and poor finite verb morphology skills in pre-kindergarten may be at risk for poor expressive language outcomes. However, these results need to be replicated with larger groups. LEARNING OUTCOMES The reader should (1) have a general understanding of findings from studies on morpho-syntax and SSD conducted over the last half century (2) be aware of some potential areas of morpho-syntactic weakness in young children with SSD who nonetheless have typical MLU, and (3) be aware of some potential longitudinal predictors of continued language difficulty in young children with SSD and poor MLU.

The impact of bilingual language learning on whole-word complexity and segmental accuracy among children aged 18 and 36 months.

This study investigates the phonological acquisition of 19 monolingual English children and 21 English–French bilingual children at 18 and 36 months. It contributes to the understanding of age-related changes to phonological complexity and to differences due to bilingual language development. In addition, preliminary normative data is presented for English children and English–French bilingual children. Five measures were targeted to represent a range of indices of phonological development: the phonological mean length of utterance (pMLU) of the adult target, the pMLU produced by the child, the proportion of whole-word proximity (PWP), proportion of consonants correct (PCC), and proportion of whole words correct (PWC). The measures of childrens productions showed improvements from 18 to 36 months; however, the rate of change varied across the measures, with PWP improving faster, then PCC, and finally PWC. The results indicated that bilingual children can keep pace with their monolingual peers at both 18 months and 36 months of age, at least in their dominant language. Based on these findings, discrepancies with monolingual phonological development that one might observe in a bilingual childs non-dominant language could be explained by reduced exposure to the language rather than a general slower acquisition of phonology.