Consonant cluster development in two-year-olds: general trends and individual difference

Late phonological development in Williams syndrome

Williams syndrome is a neurodevelopmental genetic disorder characterized by a unique phenotype, including mild to moderate intellectual disability and an uneven neuropsychological profile of relative strengths and weaknesses. Language structure components (i.e., phonology, morphosyntax, and vocabulary) have been considered an area of specific ability compared to pragmatic language use. However, research on phonological development in Williams syndrome is very scarce, and it suggests atypical patterns. Therefore, the aim of the present study was to explore the profiles of late phonological development in Spanish-speaking children, adolescents, and adults with Williams syndrome, based on the analysis of five classes of processes (Syllable Structure, Substitution, Omission, Assimilation, and Addition) in spontaneous speech. The phonological profiles of seven children (aged 3-8 years), and seven adolescents and young adults (aged 14-25 years) with Williams syndrome were compared with two normative groups of typically developing (TD) children at different stages of late phonological development (aged 3 and 5 years). The frequency of phonological processes in the group of children with Williams syndrome was similar to that of 3-year-old TD children, which suggests that they would be in the first stage of late phonological development (expansion stage). The group of older individuals with Williams syndrome showed a much lower frequency of processes, similar to that of 5-year-old TD children in the last stage of phonological development (resolution stage). However, their phonological processes appeared to be persistent and independent of chronological age. Furthermore, asynchronies in quantitative and qualitative profiles (relative frequency) indicated atypical and complex trajectories in late phonological development, which cannot be described as simply delayed or protracted. Remarkable individual differences were observed, especially in the group of adolescents and adults with Williams syndrome, although the majority of cases conformed to the modal profiles of their groups. A major tendency for Omission, including final consonant deletion, may be considered atypical and specific to Williams syndrome at all ages. The results of the present study raise the need for continued and appropriate phonological assessment and treatment for people with Williams syndrome across the lifespan.

Speech sound acquisition in Azeri Turkish-speaking children in Iran

BACKGROUND

Currently no data exist on the acquisition of speech sounds in Azeri Turkish-speaking children in Iran. This investigation was conducted to describe phonological development in Azeri Turkish-speaking children.

METHODS

A total of 120 typically developing Azeri Turkish-speaking children within the age range of 3;0 to 4;11 years were recruited. They were asked to name pictures in the Azeri Turkish Speech Test and their productions were analyzed to determine consonant acquisition, Percentage of Consonants Correct (PCC), Percentage of Vowels Correct (PVC), and Whole Word Proximity (WWP) according to sex and age. In addition, PCC values in terms of consonant position in the syllable (syllable-initial and syllable-final), and manner of articulation were calculated.

RESULTS

For consonant acquisition, they mastered all consonants except [d, d͡z, t͡s, ʒ, v, ɟ] by 4;11 years of age. PCC values increased with increasing age (H(3)= 67.212, p <0.001). In terms of manner of articulation, PCC showed that nasals were most accurately produced and trill sound least accurate. The effect of sex on PCC values was not significant U (N_males =60, N_females =60)= 1686.5, z = -0.600, p=.54). WWP values were also found to increase in older children H(3)=46.94, p<.001). Similarly, the effect of sex on WWP values was not significant U (N_males =60, N_females =60)= 1782.5, z = -0.09, p=.92).

CONCLUSIONS

Children acquiring speech sounds in the Azeri Turkish language show some similar tendencies to children acquiring other languages but are also different. Findings of the present research describe phonological development in Azeri Turkish-speaking children, which has not been documented before.

Predicting Which Children Will Normalize Without Intervention for Speech Sound Disorders

PURPOSE

The speech of some children does not follow a typical normalization trajectory, and they develop speech sound disorders (SSD). This study investigated predictive correlates of speech sound normalization in children who were at risk of SSD.

METHOD

A prospective population cohort study of 845 Cantonese-speaking preschoolers was conducted over 2.5 years to examine (a) children who resolved nonadult realizations of consonants (normalized) and (b) those who had persisting speech sound difficulties (did not normalize). From these 845, a sample of 82 participants characterized as having SSD (1.25 SDs below the mean in a standardized speech assessment, with a delay in initial consonant acquisition or with one or more atypical errors) was followed for 2 years at 6-month intervals or until the completion of their initial consonant inventory. Data from 43 children who did not receive speech-language pathology services were analyzed with survival analysis to model time to normalization while controlling for covariates. The target event (outcome) was the completion of their initial consonant inventory.

RESULTS

Under the no-intervention condition, the estimated median time to normalization was 6.59 years of age. Children who were more likely to normalize or normalized in a shorter time were stimulable to all errors and more intelligible as rated by caregivers using the Intelligibility in Context Scale. Those who showed atypical error patterns did not necessarily take longer to normalize. Similarly, expressive language ability was not significantly associated with speech normalization.

CONCLUSIONS

Stimulability and intelligibility were more useful prognostic factors of speech normalization when compared to (a)typicality of error patterns and expressive language ability. Children with low intelligibility and poor stimulability should be prioritized for speech-language pathology services given that their speech errors are less likely to resolve naturally.

Phonological acquisition of Brazilian Portuguese: Ages of customary production, acquisition and mastery

BACKGROUND

AIMS: To describe typical phonological development of Brazilian Portuguese (BP)-speaking children, considering the following parameters: age of customary production, acquisition and mastery.

METHODS & PROCEDURES

Data were collected from 857 children aged between 3 years and 8 years 11 months with typical language and speech development. The sample was grouped into 6-month age bands. The data were analysed using one-way analysis of variance (ANOVA) followed by Games-Howell post-hoc tests.

OUTCOMES & RESULTS

Stops (/p, b, t, d, k, g/), nasals (/m, n, ɲ/) and some fricatives (/f, v, s, z/) were mastered before the age of 3 years (age of mastery). The age of acquisition for phonemes /ʃ, ʒ/ was 3;6, though both were only mastered at 4;0 years. The liquid /l/ was acquired at 3;0 and mastered at age 3;6, while /x/ was acquired and mastered at age 3;6. The phoneme /ʎ/ was acquired at 7;0 and mastered at age 8;6. The tap /ɾ/ was acquired between the ages of 4;0 and 4;6, and mastered at 4;6. In coda position, /n, l/ were acquired at 3;0, while /s/ was mastered at 4;6 and /ɾ/ between 4;6 and 5;0 years. Clusters involving /ɾ/ were acquired at 6;0, while those with /l/ were acquired between the ages of 6;6 and 7;0.

CONCLUSIONS & IMPLICATIONS

This study presented acquisition for consonants in BP and can be used as a reference for the assessment of developmental speech disorders. In this study, stops and nasals were acquired first, followed by fricatives and, lastly, liquids. This finding is corroborated by previous studies in BP and other languages.

WHAT THIS PAPER ADDS

What is already known on the subject What this paper adds to existing knowledge What are the potential or actual clinical implications of this work?

Consonant cluster acquisition in Chilean children with typical and protracted phonological development

The current study addresses the acquisition of tautosyllabic consonant clusters (CCs) in Chilean preschoolers with typical (TD) versus protracted phonological development (PPD). The objectives were to analyze accuracy of CCs and mismatch (error) patterns as a function of age (4/ 5 years) and TD/PPD group, examining effects of sonority, stress, place of articulation and development of /l/ and /ɾ/ as singletons. Participants included 20 Chilean Spanish-speaking children with TD and 20 with PPD (ages 4 and 5 years). The TD group showed higher accuracy and an age effect. For both developmental groups, timing unit match was higher than full segmental match. CCs with labial and voiceless C1s in stressed syllables were most accurate. In the PPD group, deletions predominated over substitutions, deletions of C1 were significantly higher and the typology of substitutions was more differentiated. Results are evaluated in light of previous research on Chilean preschoolers, and clinical implications are discussed.

Icelandic Children's Acquisition of Consonants and Consonant Clusters

Purpose This study investigated Icelandic-speaking children's acquisition of singleton consonants and consonant clusters. Method Participants were 437 typically developing children aged 2;6-7;11 (years;months) acquiring Icelandic as their first language. Single-word speech samples of the 47 single consonants and 45 consonant clusters were collected using Málhljóðapróf ÞM (ÞM's Test of Speech Sound Disorders). Results Percentage of consonants correct for children aged 2;6-2;11 was 73.12 (SD = 13.33) and increased to 98.55 (SD = 3.24) for children aged 7;0-7;11. Overall, singleton consonants were more likely to be accurate than consonant clusters. The earliest consonants to be acquired were /m, n, p, t, j, h/ in word-initial position and /f, l/ within words. The last consonants to be acquired were /x, r, r̥, s, θ, n̥/, and consonant clusters in word-initial /sv-, stl-, str-, skr-, θr-/, within-word /-ðr-, -tl-/, and word-final /-kl̥, -xt/ contexts. Within-word phonemes were more often accurate than those in word-initial position, with word-final position the least accurate. Accuracy of production was significantly related to increasing age, but not sex. Conclusions This is the first comprehensive study of consonants and consonant cluster acquisition by typically developing Icelandic-speaking children. The findings align with trends for other Germanic languages; however, there are notable language-specific differences of clinical importance.

Children's English Consonant Acquisition in the United States: A Review

Purpose Speech-language pathologists' clinical decision making and consideration of eligibility for services rely on quality evidence, including information about consonant acquisition (developmental norms). The purpose of this review article is to describe the typical age and pattern of acquisition of English consonants by children in the United States. Method Data were identified from published journal articles and assessments reporting English consonant acquisition by typically developing children living in the United States. Sources were identified through searching 11 electronic databases, review articles, the Buros database, and contacting experts. Data describing studies, participants, methodology, and age of consonant acquisition were extracted. Results Fifteen studies (six articles and nine assessments) were included, reporting consonant acquisition of 18,907 children acquiring English in the United States. These cross-sectional studies primarily used single-word elicitation. Most consonants were acquired by 5;0 (years;months). The consonants /b, n, m, p, h, w, d/ were acquired by 2;0-2;11; /ɡ, k, f, t, ŋ, j/ were acquired by 3;0-3;11; /v, ʤ, s, ʧ, l, ʃ, z/ were acquired by 4;0-4;11; /ɹ, ð, ʒ/ were acquired by 5;0-5;11; and /θ/ was acquired by 6;0-6;11 (ordered by mean age of acquisition, 90% criterion). Variation was evident across studies resulting from different assessments, criteria, and cohorts of children. Conclusions These findings echo the cross-linguistic findings of McLeod and Crowe (2018) across 27 languages that children had acquired most consonants by 5;0. On average, all plosives, nasals, and glides were acquired by 3;11; all affricates were acquired by 4;11; all liquids were acquired by 5;11; and all fricatives were acquired by 6;11 (90% criterion). As speech-language pathologists apply this information to clinical decision making and eligibility decisions, synthesis of knowledge from multiple sources is recommended.

Holistic Communication Assessment for Young Children With Cleft Palate Using the International Classification of Functioning, Disability and Health:Children and Youth

Purpose Children with a cleft palate (± cleft lip; CP±L) can have difficulties communicating and participating in daily life, yet speech-language pathologists typically focus on speech production during routine assessments. The International Classification of Functioning, Disability and Health: Children and Youth Version (ICF-CY; World Health Organization, 2007) provides a framework for holistic assessment. This tutorial describes holistic assessment of children with CP±L illustrated by data collected from a nonclinical sample of seven 2- to 3-year-old children, 13 parents, and 12 significant others (e.g., educators and grandparents). Method Data were collected during visits to participants' homes and early childhood education and care centers. Assessment tools applicable to domains of the ICF-CY were used to collect and analyze data. Child participants' Body Functions including speech, language, and cognitive development were assessed using screening and standardized assessments. Participants' Body Structures were assessed via oral motor examination, case history questionnaires, and observation. Participants' Activities and Participation as well as Environmental and Personal Factors were examined through case history questionnaires, interviews with significant others, parent report measures, and observations. Results Valuable insights can be gained from undertaking holistic speech-language pathology assessments with children with CP±L. Using multiple tools allowed for triangulation of data and privileging different viewpoints, to better understand the children and their contexts. Several children demonstrated speech error patterns outside of what are considered cleft speech characteristics, which underscores the importance of a broader assessment. Conclusion Speech-language pathologists can consider incorporating evaluation of all components and contextual factors of the ICF-CY when assessing and working with young children with CP±L to inform intervention and management practices.

Screening Children's Speech: The Impact of Imitated Elicitation and Word Position

Purpose

Diagnostic decision making is influenced by the attributes of assessments. In order to propose time-efficient protocols for screening children's speech, this study aimed to determine whether eliciting imitated responses and analyzing productions in different word positions resulted in different levels of consonant accuracy.

Method

Participants were 267 English-speaking preschool-age children in the Sound Start Study whose parents were concerned about their speech. They were assessed using the International Speech Screener: Research Version (ISS; McLeod, 2013 ) using either imitated or spontaneous elicitation. Productions were compared with an established diagnostic assessment of speech accuracy (Diagnostic Evaluation of Articulation and Phonology; Dodd, Hua, Crosbie, Holm, & Ozanne, 2002 ).

Results

Participants' performance on the ISS was significantly correlated with performance on the Diagnostic Evaluation of Articulation and Phonology. Eliciting imitated productions on the ISS ( M = 2:18 min, SD = 0:59 min) took significantly less time than spontaneous productions ( M = 6:32 min, SD = 2:34 min). There was no significant difference in accuracy of imitated versus spontaneous productions in word-initial position; however, consonants were significantly less accurate in spontaneous than imitated productions in other word positions. Overall, participants had significantly lower consonant accuracy in word-initial position than within-word or word-final positions. Examination of the influence of word position on test discrimination, using receiver operating characteristic analyses, revealed acceptable test discrimination for percentage of consonants correct across word positions.

Conclusion

This research supports using imitated elicitation and analysis of percentage of consonants correct in word-initial position as a time-efficient procedure when screening the speech of English-speaking preschool children.

Children's Consonant Acquisition in 27 Languages: A Cross-Linguistic Review

PURPOSE

The aim of this study was to provide a cross-linguistic review of acquisition of consonant phonemes to inform speech-language pathologists' expectations of children's developmental capacity by (a) identifying characteristics of studies of consonant acquisition, (b) describing general principles of consonant acquisition, and (c) providing case studies for English, Japanese, Korean, and Spanish.

METHOD

A cross-linguistic review was undertaken of 60 articles describing 64 studies of consonant acquisition by 26,007 children from 31 countries in 27 languages: Afrikaans, Arabic, Cantonese, Danish, Dutch, English, French, German, Greek, Haitian Creole, Hebrew, Hungarian, Icelandic, Italian, Jamaican Creole, Japanese, Korean, Malay, Maltese, Mandarin (Putonghua), Portuguese, Setswana (Tswana), Slovenian, Spanish, Swahili, Turkish, and Xhosa.

RESULTS

Most studies were cross-sectional and examined single word production. Combining data from 27 languages, most of the world's consonants were acquired by 5;0 years;months old. By 5;0, children produced at least 93% of consonants correctly. Plosives, nasals, and nonpulmonic consonants (e.g., clicks) were acquired earlier than trills, flaps, fricatives, and affricates. Most labial, pharyngeal, and posterior lingual consonants were acquired earlier than consonants with anterior tongue placement. However, there was an interaction between place and manner where plosives and nasals produced with anterior tongue placement were acquired earlier than anterior trills, fricatives, and affricates.

CONCLUSIONS

Children across the world acquire consonants at a young age. Five-year-old children have acquired most consonants within their ambient language; however, individual variability should be considered.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.6972857.

Phonological processes in the speech of school-age children with hearing loss: Comparisons with children with normal hearing

PURPOSE

In this descriptive study, phonological processes were examined in the speech of children aged 5;0-7;6 (years; months) with mild to profound hearing loss using hearing aids (HAs) and cochlear implants (CIs), in comparison to their peers. A second aim was to compare phonological processes of HA and CI users.

METHOD

Children with hearing loss (CWHL, N = 25) were compared to children with normal hearing (CWNH, N = 30) with similar age, gender, linguistic, and socioeconomic backgrounds. Speech samples obtained from a list of 88 words, derived from three standardized speech tests, were analyzed using the CASALA (Computer Aided Speech and Language Analysis) program to evaluate participants' phonological systems, based on lax (a process appeared at least twice in the speech of at least two children) and strict (a process appeared at least five times in the speech of at least two children) counting criteria.

RESULTS

Developmental phonological processes were eliminated in the speech of younger and older CWNH while eleven developmental phonological processes persisted in the speech of both age groups of CWHL. CWHL showed a similar trend of age of elimination to CWNH, but at a slower rate. Children with HAs and CIs produced similar phonological processes. Final consonant deletion, weak syllable deletion, backing, and glottal replacement were present in the speech of HA users, affecting their overall speech intelligibility.

CONCLUSIONS

Developmental and non-developmental phonological processes persist in the speech of children with mild to profound hearing loss compared to their peers with typical hearing. The findings indicate that it is important for clinicians to consider phonological assessment in pre-school CWHL and the use of evidence-based speech therapy in order to reduce non-developmental and non-age-appropriate developmental processes, thereby enhancing their speech intelligibility.

Temporal features of word-initial /s/+stop clusters in bilingual Mandarin-English children and monolingual English children and adults

This study investigated the durational features of English word-initial /s/+stop clusters produced by bilingual Mandarin (L1)-English (L2) children and monolingual English children and adults. The participants included two groups of five- to six-year-old bilingual children: low proficiency in the L2 (Bi-low) and high proficiency in the L2 (Bi-high), one group of age-matched English children, and one group of English adults. Each participant produced a list of English words containing /sp, st, sk/ at the word-initial position followed by /a, i, u/, respectively. The absolute durations of the clusters and cluster elements and the durational proportions of elements to the overall cluster were measured. The results revealed that Bi-high children behaved similarly to the English monolinguals whereas Bi-low children used a different strategy of temporal organization to coordinate the cluster components in comparison to the English monolinguals and Bi-high children. The influence of language experience and continuing development of temporal features in children were discussed.

The acquisition of initial consonant clusters in German-speaking 2-year-olds

PURPOSE

The aim of this study was to explore cluster acquisition in typically developing German-speaking 2-year-olds.

METHOD

Data from four cross-sectional studies (n = 145, aged 2;00-2;11) and one eight-month longitudinal study were analysed (n = 6, aged 2;01-2;04). Two different percentages of consonant clusters correct were calculated to allow a more detailed analysis.

RESULT

Findings showed that the majority of children produced clusters, although they could not be considered to be fully acquired. Correct production significantly correlated with age. Only /gl/ and /kl/ were shown to be phonetically and phonemically acquired (75% criterion) in the older age group. Three-element clusters were acquired at the same time as 2-element clusters and /∫/-clusters were acquired to the same or larger extent as non-/∫/ clusters when fronting/backing of /∫/ was accepted. Younger children produced more reductions than simplifications but this effect was less strong for the /∫/-clusters. Developmental realisation patterns varied depending on cluster type. Inter- and intra-individual developmental patterns could be observed which changed depending on the time of testing.

CONCLUSION

Findings on cluster acquisition in 2-year-old German-speaking children revealed language-specific differences but also similarities in comparison with results from other languages. All but two children produced clusters. However, individual variation between children was high.

Early phonetic development in typically developing children: A longitudinal investigation from Cypriot-Greek child data

The current longitudinal study examined the acquisition of consonantal singleton segments in Cypriot-Greek. The study's aims were: (a) to determine the acquisition of segments for manner and place of articulation as a function of age and word position, (b) to provide preliminary normative data, and (c) to further support the cross-linguistic data pool regarding developmental phonology patterns. Participants were 14 Cypriot-Greek speaking typically developing toddlers, examined at ages 24, 28, 32 and 36 months. Spontaneously produced and elicited glossable utterances were used in constructing each child's inventory. Findings revealed an increase of segmental acquisition across all age levels. Group trend analysis for manner and place of articulation indicated bilabial and alveolar stops and nasals to be among the earlier segments to develop. A word medial position advantage was also evident. The findings are discussed in terms of phonological universals and language-specific factors. Implications for early evidence-based phonetic assessment are discussed.

Acquisition of Consonant Clusters and Acceptable Variants in Chinese-Influenced Malaysian English-Speaking Children

PURPOSE

This study investigated consonant cluster acquisition in Chinese-influenced Malaysian English (ChME)-speaking children.

METHOD

This cross-sectional study involved 262 typically developing ChME-speaking children (138 girls, 124 boys) ages 3 to 7 years old. A single-word picture-naming task, which contained 66 words and targeted 32 syllable-initial (SI) and 14 syllable-final (SF) consonant clusters, was administered.

RESULTS

Older children produced more correct productions than younger children, and there was no sex effect for consonant cluster production. SF consonant clusters were more accurate than SI consonant clusters among the younger children. The overall sequence of SI consonant cluster accuracy based on cluster categories from most to least accurate was /s/ + C, C + /w/, C + /j/, C + /l/, and C + /r/, whereas for SF consonant clusters, the order was C + stop, C + /s/, nasal + C, and /l/ + C. Two-element clusters consistently had higher accuracy in comparison to three-element clusters across the age groups. The overall consonant cluster accuracy of the present study showed similar patterns to those found in previous studies of Standard English.

CONCLUSION

The findings of the study will be useful in the assessment of consonant cluster production of ChME-speaking children.

Content coverage of single-word tests used to assess common phonological error patterns

PURPOSE

This review evaluated whether 9 single-word tests of phonological error patterns provide adequate content coverage to accurately identify error patterns that are active in a child's speech.

METHOD

Tests in the current study were considered to display sufficient opportunities to assess common phonological error patterns if they provided at least 4 opportunities for each of 11 error patterns. The target phonemes for these error patterns had to occur as singletons (except for final consonant deletion and cluster reduction) and in stressed syllables (except for weak syllable deletion). Error patterns for which positional asymmetries have been documented (velar fronting, stopping of fricatives and affricates, and cluster reduction) required 4 opportunities in both word-initial and word-final position to meet the study's criterion.

RESULTS

None of the tests provided 4 opportunities for every error pattern, the criterion level used in this study. Error patterns that tended to be underrepresented across tests included weak syllable deletion, reduction of word-final clusters, fronting of velars, gliding of liquids, and deaffrication.

CONCLUSION

This review will allow clinicians to gain a deeper understanding of the methods used to assess phonological error patterns in single-word tests.

Cross-linguistic comparison of speech errors produced by English- and French-speaking preschool-age children with developmental phonological disorders

Twenty-four French-speaking children with developmental phonological disorders (DPD) were matched on percentage of consonants correct (PCC)-conversation, age, and receptive vocabulary measures to English-speaking children with DPD in order to describe how speech errors are manifested differently in these two languages. The participants' productions of consonants on a single-word test of articulation were compared in terms of feature-match ratios for the production of target consonants, and type of errors produced. Results revealed that the French-speaking children had significantly lower match ratios for the major sound class features [+ consonantal] and [+ sonorant]. The French-speaking children also obtained significantly lower match ratios for [+ voice]. The most frequent type of errors produced by the French-speaking children was syllable structure errors, followed by segment errors, and a few distortion errors. On the other hand, the English-speaking children made more segment than syllable structure and distortion errors. The results of the study highlight the need to use test instruments with French-speaking children that reflect the phonological characteristics of French at multiple levels of the phonological hierarchy.

The role of utterance length and position in 3-year-olds' production of third person singular -s

PURPOSE Evidence from children's spontaneous speech suggests that utterance length and utterance position may help explain why children omit grammatical morphemes in some contexts but not others. This study investigated whether increased utterance length (hence, increased grammatical complexity) adversely affects children's third person singular -s production in more controlled experimental conditions. METHOD An elicited imitation task with 12 Australian English-speaking children ages 2;9 (years;months) to 3;2 (Mage = 2;11) was conducted comparing third person singular -s production in 3-word and 5-word utterances, both utterance medially (e.g., He sits back; He sits back and swings) and utterance finally (e.g., There he sits; That's the way he sits) using a within-subjects design. Children were shown pictorial representations of each utterance on a computer and were invited to repeat 16 pseudorandomized prerecorded utterances. Acoustic analysis determined the presence/absence and duration of the third person singular morpheme. RESULTS Third person singular production was significantly lower utterance medially compared to utterance finally for the 5-word utterances and significantly lower utterance medially in the 5-word compared to 3-word utterances. CONCLUSION These results suggest that increased utterance length results in significantly lower third person singular production, but only in the more articulatorily challenging utterance-medial position. Thus, morpheme omission is greatest at the intersection of grammatical and phonological complexity.

Typical consonant cluster acquisition in auditory-verbal children with early-identified severe/profound hearing loss

Early-identified severe/profound hearing loss (HL) following universal newborn hearing screening (UNHS) has been associated with improved speech and language outcomes. However, speech outcome reports have typically been based on broad measures of speech intelligibility and/or singleton consonant accuracy, with little known about production of consonant clusters. Using a prospective design, the range and accuracy of consonant clusters produced by a homogenous cohort of 12 children early-identified with severe/profound HL aged 3- and 4-years were examined. All children demonstrated bilateral aided thresholds within a range of 15-25 dB HL across all frequencies, were optimally amplified with cochlear implants (11/12) or hearing aids (1/12), and attended auditory-verbal (AV) early intervention. Standardized speech and language assessments were administered. Consonant clusters were strategically sampled in single-word and conversational speech contexts. All standard scores for speech, receptive, and expressive language were within normal limits. All children produced consonant clusters commensurate with expectations for typically-developing hearing peers at 3- and 4- years-of-age. Children's production of phonetically complex morphophonemes (final consonant clusters marking grammatical morphemes) was also in keeping with developmental expectations. Factors which contributed to these encouraging outcomes require further investigation.

Acoustic investigations into the later acquisition of syllabic -es plurals

PURPOSE

Children acquire /-z/ syllabic plurals (e.g., bus es) later than /-s, -z/ segmental plurals (e.g., cat s, dog s). In this study, the authors explored whether increased syllable number or segmental factors best explains poorer performance with syllabic plurals.

METHOD

An elicited imitation experiment was conducted with 14 two-year-olds involving 8 familiar disyllabic target plural nouns, half with syllabic plurals (e.g., bus → bus es) and half with segmental plurals (e.g., letter → letter s). Children saw pictures of the target items on a computer and repeated prerecorded 3-word-utterances with the target word in utterance-medial position (e.g., "The buses come") and utterance-final position (e.g., "Hear the buses"). Acoustic analysis determined the presence or absence of the plural morpheme and its duration.

RESULTS

Children had more trouble producing syllabic plurals compared with segmental plurals. Errors were especially evident in the utterance-medial position, where there was less time for the child to perceive/produce the word in the absence of phrase-final lengthening and where planning for the following word was still required.

CONCLUSIONS

The results suggested that articulatory difficulties-rather than a word length effect-explain later acquisition of syllabic plurals relative to segmental plurals. These findings have implications for the nature of syllabic plural acquisition in children with hearing impairments and specific language impairment.

Longitudinal changes in phonological whole-word measures in 2-year-olds

The purpose of this investigation was to describe changes in whole-word productions in the speech of children as they aged from 24 to 36 months. Spontaneous language samples were obtained from 12 participants during parent-child interactions every 3 months, beginning with each participant's second birthday. Fifty different words from each sample were analysed to determine changes in a variety of whole-word measures including phonological mean length of utterance (PMLU) for target words and words produced, proportion of whole-word proximity (PWP), and proportion of words produced correctly (PWC). Significant changes in whole-word measures were evidenced by the participants over the course of the investigation, and those scores did not show stabilization by the age of 36 months.

Identification of phonological processes in preschool children's single-word productions

BACKGROUND

Speech and language therapists often refer to phonological data norms as part of their assessment protocols in evaluating the communication skills of the preschool child. There is a variety of norms available, and although broadly similar, differences are embedded within their definitions of mastery of the adult target system.

AIMS

To compare phonological processes present in the single-word productions of 94 West of Scotland preschool children with published normative data relating to typical ages of elimination of phonological processes.

METHODS & PROCEDURES

The 94 children, grouped into four 6-month age bands from 3.1 to 4.11 years, named 78 pictures. Their responses were broadly transcribed and then analysed for phonological processes.

OUTCOMES & RESULTS

The presence of velar fronting, stopping of affricates and [s] cluster reduction in the data set was found to mirror previous research. However, there was a lower-than-expected incidence by age groups of palato-alveolar fronting, stopping of fricatives and obstruent cluster reduction.

CONCLUSIONS & IMPLICATIONS

Speech and language therapists frequently rely on phonological normative data as part of their assessment and management of children with speech delay. Evidence from children recruited from typical mainstream nursery classes indicates that there are distinct differences between what would be expected of them with reference to normative data for some phonological processes and what they produce. UK clinical guidelines recommend the consideration of both the acquisition of phonemes and the presence of phonological processes when assessing and planning intervention. However, differences in development and occurrence within processes in relation to phonological development may have implications for clinicians' decision-making. Further research is proposed in relation to the extent to which phonological norms contribute to such clinical decision-making.

On the context-dependent nature of the contribution of the ventral premotor cortex to speech perception

What is the nature of the interface between speech perception and production, where auditory and motor representations converge? One set of explanations suggests that during perception, the motor circuits involved in producing a perceived action are in some way enacting the action without actually causing movement (covert simulation) or sending along the motor information to be used to predict its sensory consequences (i.e., efference copy). Other accounts either reject entirely the involvement of motor representations in perception, or explain their role as being more supportive than integral, and not employing the identical circuits used in production. Using fMRI, we investigated whether there are brain regions that are conjointly active for both speech perception and production, and whether these regions are sensitive to articulatory (syllabic) complexity during both processes, which is predicted by a covert simulation account. A group of healthy young adults (1) observed a female speaker produce a set of familiar words (perception), and (2) observed and then repeated the words (production). There were two types of words, varying in articulatory complexity, as measured by the presence or absence of consonant clusters. The simple words contained no consonant cluster (e.g. "palace"), while the complex words contained one to three consonant clusters (e.g. "planet"). Results indicate that the left ventral premotor cortex (PMv) was significantly active during speech perception and speech production but that activation in this region was scaled to articulatory complexity only during speech production, revealing an incompletely specified efferent motor signal during speech perception. The right planum temporal (PT) was also active during speech perception and speech production, and activation in this region was scaled to articulatory complexity during both production and perception. These findings are discussed in the context of current theories of speech perception, with particular attention to accounts that include an explanatory role for mirror neurons.

Phonetic and phonemic acquisition: normative data in English and Dutch speech sound development

OBJECTIVE

Comparison of normative data in English and Dutch speech sound development in young children. Research questions were: Which normative data are present concerning speech sound development in children between two and six years of age? In which way are the speech sounds examined? What are the differences and similarities between the development of speech sounds in different languages?

METHODS

A literature study on the subject was performed to be able to answer the research questions.

RESULTS

The presented normative English data showed that all vowels are present at three years of age, and most consonants (singletons) already at four years of age, except for/ʃ, ɹ, θ, ð/. Consonant clusters develop between 4.5 and 5.5 years of age. The phonological error patterns gliding can be present until six years of age. According to information regarding the Dutch speech sound system, the same ages are found for vowels and single consonants. The age of acquisition of most consonant clusters is present at about six years of age, but the development goes on until ten years of age.

CONCLUSION

The data from the development of the English and Dutch speech sound system show many similar tendencies. Vowels are mastered by the age of three, most consonants by the age of four and most consonant clusters between 5 and 6-8 years of age. Perhaps, there is a universal trend in speech sound development like there is in language development.

Two-year-old phonology: impact of input, motor and cognitive abilities on development

Previous research has rarely compared the contributions of different underlying abilities to phonological acquisition. In this study, the auditory-visual speech perception, oro-motor and rule abstraction skills of 62 typically developing two-year olds were assessed and contrasted with the accuracy of their spoken phonology. Measures included auditory-visual speech perception, production of isolated and sequenced oro-motor movements, and verbal and non-verbal rule abstraction. Abilities in all three domains contributed to phonological acquisition. However, the use of atypical phonological rules was associated with lower levels of phonological accuracy and a linear regression indicated that this measure of rule abstraction had greater explanatory power than the measures of input processing and output skill.

Acquisition of /s/ clusters in English-speaking children with phonological disorders

Two member onset consonant clusters with /s/ as the first member (#sC onsets) behave differently from other double onset consonant clusters in English. Phonological explanations of children's consonant cluster production have been posited to predict children's speech acquisition. The aim of this study was to consider the role of the Sonority Sequencing Principle (SSP), homorganicity, headedness, and factorial typology in the explanation of productions of consonant clusters by children with phonological disorders. Thirty monolingual English-speaking children with phonological disorders produced words commencing with #sC: /s/+stop (/sT/), /s/+nasal (/sN/), /sl/, and /sw/. There was wide individual variation between participants. Overall, there was an increase in accuracy of consonant cluster production as the sonority indices of the second element of the cluster increased: there was significantly greater accuracy of /sl/ than /sN/ and significantly greater accuracy of /sN/ than /sT/. However, /sw/ targets only followed the SSP for phonologically accurate (but not phonetically accurate) productions. Correct renditions justified the binary grouping of the SSP-following vs SSP-violating separation. Homorganicity of the cluster was not a factor in determining relative accuracy of the targets. The percentage of correct renditions justified the /s/+[-continuant] vs /s/+[+continuant] binary separation. There were several counterexamples of predictions of the headedness approach. Thus, sonority and factorial typology were found to be useful in predicting /s/ consonant cluster acquisition of children with phonological disorders.

An analysis of the sonority hypothesis and cluster realization in a child with phonological disorder

This study describes the realization of onset and coda clusters in a 4-year old child acquiring American English, and with a higher than usual level of unintelligible speech. It reviews previous studies that have tested cluster realization against markedness and, in particular, the sonority hypothesis. This latter predicts steep rises in sonority at onsets and more gradual falls in sonority at codas of syllables. The data collected for this study cover four different onset cluster types and three different coda cluster types, and are derived from spontaneous speech produced during clinical sessions. An analysis of the patterns of cluster realizations shows that the participant's cluster realizations do not always follow the sonority hypothesis, and various factors are discussed that could be motivating the child's choice of realization.

Phonological Milestones for African American English-Speaking Children Learning Mainstream American English as a Second Dialect

Purpose

This study provides milestones for phonological development in African American English (AAE) speakers who are learning Mainstream American English (MAE) as a second dialect.

Method

The Dialect Sensitive Language Test (DSLT; H. Seymour, T. Roeper, & J. G. de Villiers, 2000) was administered to a nationwide sample of typically developing children ages 4 through 12: 537 speakers of AAE as a first dialect and 317 speakers of MAE as a first dialect. DSLT items tested all consonant segments and many clusters of MAE in initial and final position. The age at which each dialect group reached 90% criterion for each segment in each position was compared.

Results

Several phonetic elements that are contrastive between the dialects (i.e., differentiate the dialects) in word-finalposition were found to be similar in the 2 groups in word-initialposition. Only /ð/ was contrastive in both positions. We confirm the later acquisition of certain phonological segments and structures by AAE speakers compared to MAE speakers and report their earlier mastery of other elements of MAE phonology.

Conclusion

Both segmental and phonotactic development show different trajectories for AAE and MAE. Thus, initial diagnosis of impairment for AAE children should focus only on mastery of noncontrastive segments and structures that share a similar developmental profile for the 2 dialect groups.

Reviewing sonority for word-final sonorant+obstruent consonant cluster development in Turkish

The purpose of this study is to investigate the acquisition patterns of sonorant+obstruent coda clusters in Turkish to determine whether Turkish data support the prediction the Sonority Sequencing Principle (SSP) makes as to which consonant (i.e. C1 or C2) is more likely to be preserved in sonorant+obstruent clusters, and the error patterns of sonorant+obstruent coda clusters. Data from 350 typically developing monolingual Turkish speaking children (aged 2.0-5.11 years) were used in this study. Six types of sonorant+obstruent clusters were targeted for analysis of deletion, vowel lengthening, and substitution processes in C1 and C2 singletons of clusters separately. The results showed that the acquisition of Turkish clusters does not adhere to the SSP as indicated by a higher percentage of C1 errors than C2 errors. In Turkish, vowel lengthening occurred when C1 was deleted. To account for these, it is proposed that the syllable structure of Turkish plays a role in the acquisition process of sonorant+obstruent clusters. It is argued that Turkish children acquire moraic structure at an early age, as evidenced by vowel lengthening.

Speech and language development in cri du chat syndrome: a critical review

This article reviews research on speech and language abilities in people with cri du chat syndrome (CCS). CCS is a rare genetic disorder, with an estimated incidence between 1 in 15,000 and 1 in 50,000 births, resulting from a deletion on the short arm of chromosome 5. In general, individuals have delayed speech and language development, and some never develop spoken language. Their receptive language is better than their expressive language, although both are delayed. Regarding phonetics and phonology, substitutions, omissions, and distortions are frequent; consonant inventories are small; syllable shapes are restricted; and vowels are variable and overlap with each other acoustically. Persons with CCS have been found to inflect words from all major word classes. Little is known about syntactic skills, but some individuals are reported to express themselves in utterances of two or more words. Knowledge about speech and language development in CCS is sparse, and the need for more research is considerable.

Consonants in Cri du chat syndrome: a case study

This article reports on a longitudinal case study of consonant productions in one Norwegian girl with Cri du chat syndrome from age 4;6 to age 9;4. It was shown that she had many articulation errors throughout the period of observation. Furthermore, these errors were shown to fall into three main categories: (1) errors of differentiation and tuning, (2) errors of coordination and sequencing, and (3) missing gestures. Also, omissions of segments were reported to be frequent. In sum, the consonant productions by this girl were found to be both delayed and deviant, as compared to normally developing children. The number of errors, however, decreased as she grew older, resulting in more accurate renditions of the target words.

Patterns of consonant deletion in typically developing children aged 3 to 7 years

Children with and without speech, language and/or literacy impairment, delete consonants when they name pictures to elicit single words. Consonant deletion seems to be more frequent in long words (words of three or more syllables) than in short words (words of one or two syllables). However, it may be missed in long words because they are not routinely assessed and, even if they are, there is little normative data about them. The study aims were (1) to determine if a relationship exists between consonant deletion and the number of syllables in words, (2) delimit variation in the numbers of children using it, its frequency of occurrence and the words it affects and (3) to discuss the application of these data to clinical practice. The participants were 283 typically developing children, aged 3;0 to 7;11 years, speaking Australian English with proven normal language, cognition and hearing. They named pictures, yielding 166 selected words that were varied for syllable number, stress and shape and repeatedly sampled all consonants and vowels of Australian English. Almost all participants (95%) used consonant deletion. Whilst a relationship existed between consonant deletion frequency and the number of syllables in words, the syllable effect was interpreted as a proxy of an interaction of segmental and prosodic features that included two or more syllables, sonorant sounds, non-final weak syllables, within-word consonant sequences and/or anterior-posterior articulatory movements. Clinically, two or three deletions of consonants across the affected words may indicate typical behaviour for children up to the age of 7;11 years but variations outside these tolerances may mark impairment. These results are further evidence to include long words in routine speech assessment.

Two-year-olds' phonological acquisition: Normative data

The study reported evaluated an assessment of phonology for 2-year-olds to establish normative data and determine if early identification of children with speech difficulties is possible. The study evaluated 62 2-year-old children on the Toddler Phonology Test (TPT). Children produced 32 words, spontaneously or in imitation. Ten of the children were assessed three times, on the third occasion, when they had reached 3 years, on another phonological assessment. The data indicated that older children performed better than younger children on quantitative measures. Girls and boys performed equally well. Their phonetic repertoires were missing some fricatives and all affricates, as well as /r/. Consistently used error patterns identified included cluster reduction, final consonant deletion, stopping, fronting, weak syllable, deletion, gliding and deaffrication. Correlation analyses indicated that performance at the first assessment on the TPT indicated performance on subsequent assessments. While quantitative data was not a reliable predictive indicator of speech disorder, qualitative analysis of error types was predictive, with children who made many atypical errors at 2 years being diagnosed as phonologically disordered at 3 years. The findings provide initial evidence that direct formal assessment of 2-year-old phonology is possible.

Typically developing and speech-impaired children's adherence to the sonority hypothesis

During phonological development, children frequently produce consonant clusters as consonant singletons, a process commonly referred to as cluster reduction. The principles of sonority may provide a theoretical basis for explaining patterns of cluster reduction evident in children's speech. Two studies were conducted to investigate whether children's word-initial cluster reductions adhered to the sonority hypothesis. Study one involved 16 children with typically developing speech, and study two involved 40 children with impaired speech. The children's consonant cluster productions characterized by a cluster reduction were analysed. When both groups of participants reduced word-initial clusters to a target consonant, the sonority hypothesis was adhered to; but when the clusters were reduced to a non-target consonant, the sonority hypothesis was violated. Analysis of target and non-target reductions revealed that some reductions of the individual clusters, and those within specific cluster categories, adhered to the sonority hypothesis while others did not. In light of these findings, it is suggested that although sonority is a valuable concept, it may not account for all patterns of cluster reduction evident in children's speech.

Australian adults' production of /n/: an EPG investigation

Images of tongue/palate contact for the nasal phoneme /n/ were created using the electropalatograph (EPG). Seven typical Australian adults with no history of hearing or communication difficulty produced syllables containing /n/ paired with five vowels. The majority of productions were symmetrical had contact with the alveolar ridge, and lateral bracing along the sides of the palate; however, there were notable exceptions. There was a wide range of inter- and intra-participant variation in the visual representations of the maximum point of contact as well as in measures of total palate contact (TPC) and centre of gravity (COG). It is suggested that when describing acceptable production of /n/ a range of tongue/palate contact patterns are provided.