Predictors of token-to-token inconsistency in preschool children with typical speech-language development

Diagnosing inconsistent phonological disorder: quantitative and qualitative measures

Studies of children's consistency of word production allow identification of speech sound disorder. Inconsistent errors are reported for two groups of children: childhood apraxia of speech (CAS) due to difficulty with the motoric precision and consistency of speech movements; and inconsistent phonological disorder (IPD) attributed to impaired phonological planning. This paper describes the inconsistent productions of children with IPD in comparison to typically developing children. In two studies of suspected SSD (N = 135), 22 children pronounced ≥40% of 25 words inconsistently on three repeated trials. No participant had symptoms of CAS. They were monolingual and spoke Australian- or Irish-English. Assessment determined the proportions of words said consistently (i.e. the same across productions: all correct or with the same error) or inconsistently (i.e. differently across productions: at least one correct and one error or different errors in productions). Qualitative analyses examined error types and explored the effect of target words' characteristics on inconsistency. Children with IPD produced 52% of words with different errors. While 56% of all phoneme errors were developmental (age appropriate or delayed), atypical errors typified inconsistency: default sounds and word structure errors. Words with more phonemes, syllables and consonant clusters were vulnerable to inconsistency, but their frequency of occurrence had no effect. TD children and those with IPD had different quantitative and qualitative error profiles, confirming IPD as a diagnostic category of SSD. Qualitative analyses supported the hypothesised deficit in phonological planning of words' production for children with IPD.

How to cut the pie is no piece of cake: Toward a process-oriented approach to assessment and diagnosis of speech sound disorders

BACKGROUND

'Speech sound disorder' is an umbrella term that encompasses dysarthria, articulation disorders, childhood apraxia of speech and phonological disorders. However, differential diagnosis between these disorders is a persistent challenge in speech pathology, as many diagnostic procedures use symptom clusters instead of identifying an origin of breakdown in the speech and language system.

AIMS

This article reviews typical and disordered speech through the lens of two well-developed models of production-one focused on phonological encoding and one focused on speech motor planning. We illustrate potential breakdown locations within these models that may relate to childhood apraxia of speech and phonological disorders.

MAIN CONTRIBUTION

This paper presents an overview of an approach to conceptualisation of speech sound disorders that is grounded in current models of speech production and emphasises consideration of underlying processes. The paper also sketches a research agenda for the development of valid, reliable and clinically feasible assessment protocols for children with speech sound disorders.

CONCLUSION

The process-oriented approach outlined here is in the early stages of development but holds promise for developing a more detailed and comprehensive understanding of, and assessment protocols for speech sound disorders that go beyond broad diagnostic labels based on error analysis. Directions for future research are discussed.

WHAT THIS PAPER ADDS

What is already known on the subject Speech sound disorders (SSD) are heterogeneous, and there is agreement that some children have a phonological impairment (phonological disorders, PD) whereas others have an impairment of speech motor planning (childhood apraxia of speech, CAS). There is also recognition that speech production involves multiple processes, and several approaches to the assessment and diagnosis of SSD have been proposed. What this paper adds to existing knowledge This paper provides a more detailed conceptualisation of potential impairments in children with SSD that is grounded in current models of speech production and encourages greater consideration of underlying processes. The paper illustrates this approach and provides guidance for further development. One consequence of this perspective is the notion that broad diagnostic category labels (PD, CAS) may each comprise different subtypes or profiles depending on the processes that are affected. What are the potential or actual clinical implications of this work? Although the approach is in the early stages of development and no comprehensive validated set of tasks and measures is available to assess all processes, clinicians may find the conceptualisation of different underlying processes and the notion of potential subtypes within PD and CAS informative when evaluating SSD. In addition, this perspective discourages either/or thinking (PD or CAS) and instead encourages consideration of the possibility that children may have different combinations of impairments at different processing stages.

Variability, accuracy, and cross-linguistic transfer in bilingual children speaking Jamaican Creole and English

Due to the lack of normative data about bilingual speech development and limited availability of diagnostic tools optimised for this population, bilingual children under consideration for speech-language services are at an elevated risk of misdiagnosis. In the absence of validated assessment tools, speech-language pathologists may use measures of accuracy and variability of speech production to diagnose suspected speech sound disorders in bilingual children. Research in general motor development suggests that variability and accuracy may trade off in the course of maturation, whereby movement variability spikes before the transition to a more mature stage of motor control. Such variability-accuracy tradeoffs have been described in monolingual speech development but are understudied in bilingual populations, where cross-linguistic transfer occurs. This study aimed to examine variability, accuracy, and cross-linguistic transfer in the speech of 20 bilingual children speaking Jamaican Creole and English. We hypothesised that children who showed higher accuracy in their productions would also exhibit more variable speech, indicating a variability-accuracy tradeoff. The Word Inconsistency Assessment from the Diagnostic Evaluation of Articulation and Phonology was administered to measure accuracy and variability in the English context, where misdiagnosis is likely to occur. Contrary to our hypothesis, we observed that individuals with higher accuracy tended to be less variable in their productions. Future research should examine longitudinal trajectories of accuracy and variability and consider a more culturally-appropriate definition of 'accuracy' in documenting bilingual speech sound development.

Preschool children's consistency of word production

Consistency of word production contributes to carers' ability to understand children's speech. Reports of the proportion of words produced consistently by typically developing preschool children, however, vary widely from 17% to 87%. This paper examines the quantitative (consistency count) and qualitative (e.g. phonemic analysis) characteristics of word consistency in 96 children aged 36-60 months. Children named 15 pictures twice, in separate trials, in the same assessment session. The mean consistency of the production for the whole group was 82%. Older children were more consistent than younger children. Girls were more consistent than boys. Words produced correctly in one trial and in error in another may indicate resolving error patterns. Words produced in error in two different ways provided useful evidence about the nature of inconsistent word production in typically developing children. The clinical and theoretical implications are discussed.

Predictors of Speech Severity and Inconsistency Over Time in Children With Token-to-Token Inconsistency

PURPOSE

The aim of this study was to describe and explain changes in severity of speech sound disorder (SSD) and token-to-token inconsistency in children with high levels of inconsistency.

METHOD

Thirty-nine children (aged 4;6-7;11 [years;months]) with SSDs and high levels of token-to-token inconsistency were assessed every 6 months for 2 years (i.e., five assessment points). Growth modeling was used to assess relations among therapy support, receptive vocabulary, severity, and inconsistency over time.

RESULTS

Children with the most severe SSDs and highest levels of token-to-token inconsistency showed the smallest improvements in speech accuracy over time. Therapy support did not predict changes in speech accuracy or token-to-token inconsistency over time. Receptive vocabulary (measured at the outset of the study) was also a significant predictor of speech accuracy and inconsistency.

CONCLUSIONS

These findings suggest that an immediate start to intervention (rather than a wait-and-see approach) is recommended for children with inconsistent speech error patterns. The results also highlight the value of developing vocabulary knowledge in addition to improving speech accuracy for some children with inconsistent speech production.

Intraword Variability in Children With Auditory Brainstem Implants: A Longitudinal Comparison With Children With Cochlear Implants

PURPOSE

Intraword variability designates the phenomenon that a particular target word is produced variably by a child at one point in the child's development. In this study, the amount of intraword variability is studied longitudinally in children with auditory brainstem implants (ABIs). Auditory brainstem implantation is a relative recent technique in pediatric hearing restoration. Therefore, little is known about the phonological development of these children's speech.

METHOD

The intraword variability is investigated in three children with ABI, in comparison to children with cochlear implants, matched on lexical development. Intraword variability is measured using relative entropy in order to take into account the frequency distribution in children's productions.

RESULT

Results showed considerable variation between the three children with ABI. Still, all children had higher levels of intraword variability in their spontaneous speech productions as compared to children with cochlear implants.

CONCLUSION

It seems that children with ABI are lagging behind their phonological development in reference to children with cochlear implants.

A temporal-based therapy for children with inconsistent phonological disorder: A case-series

Deficits in temporal auditory processing, and in particular higher gap detection thresholds have been reported in children with inconsistent phonological disorder (IPD). Here we hypothesized that providing these children with extra time for phoneme identification may in turn enhance their phonological planning abilities for production, and accordingly improve not only consistency but also accuracy of their speech. We designed and tested a new temporal-based therapy, inspired by Core Vocabulary Therapy and called it T-CVT, where we digitally lengthened formant transitions between phonemes of words used for therapy. This allowed to target both temporal auditory processing and word phonological planning. Four preschool Persian native children with IPD received T-CVT for eight weeks. We measured changes in speech consistency (% inconsistency) and accuracy (percentage of consonants correct PCC) to assess the effects of the intervention. Therapy significantly improved both consistency and accuracy of word production in the four children: % inconsistency decreased from 59% on average before therapy to 2% post-T-CVT, and PCC increased from 61% to 92% on average. Consistency and accuracy were furthermore maintained or even still improved at three-month follow-up (2% inconsistency and 99% PCC). Results in a nonword repetition task showed the generalization of these effects to non-treated material: % inconsistency for nonwords decreased from 67% to 10% post-therapy, and PCC increased from 63% to 90%. These preliminary findings support the efficacy of the T-CVT intervention for children with IPD who show temporal auditory processing deficits as reflected by higher gap detection thresholds.

Speech inconsistency and its association with speech production, phonological awareness and nonword repetition skills

The purpose of this study was to investigate relationships between speech inconsistency, speech production skills, phonological awareness and nonword repetition (NWR) in 24 preschool-aged Finnish-speaking children with speech sound disorder (SSD) and in 31 children with typical speech and language development (TD). Speech inconsistency was assessed by a picture-naming task repeated three times during one assessment session. The participants' speech production skills were assessed with the Finnish Test for Phonology and a diadochokinetic (DDK) task. Phonological awareness was investigated by the tasks of Rhyme and initial syllable awareness and Syllable segmentation, and NWR by ten 2-4-syllabic nonwords. The findings indicated that the children with SSD were less accurate in speech production and NWR than the children with TD. No difference was found in phonological awareness. Among the children with SSD, speech inconsistency was correlated with accuracy in overall speech production, DDK task, and NWR. Among the children with TD, speech inconsistency was correlated with accuracy in overall speech production, partly with phonological awareness, and with NWR. The results provide support for the idea that when assessing speech inconsistency in children with SSD, a process-oriented approach may be needed in order to obtain an adequately broad picture of their skill profiles.

Intraword Variability in French-Speaking Monolingual and Bilingual Children

Purpose This study examines intraword variability in 40 typically developing French-speaking monolingual and bilingual children, aged 2;6-4;8 (years;months). Specifically, it measures rate of intraword variability and investigates which factors best account for it. They include child-specific ones such as age, expressive vocabulary, gender, bilingual status, and speech sound production ability, and word-specific factors, such as phonological complexity (including number of syllables), phonological neighborhood density (PND), and word frequency. Method A variability test was developed, consisting of 25 words, which differed in terms of phonological complexity, PND, and word frequency. Children produced three exemplars of each word during a single session, and productions of words were coded as variable or not variable. In addition, children were administered an expressive vocabulary test and two tests tapping speech motor ability (oral motor assessment and diadochokinetic test). Speech sound ability was also assessed by measuring percent consonants correct on all words produced by the children during the session. Data were entered into a binomial logistic regression. Results Average intraword variability was 29% across all children. Several factors were found to predict intraword variability including age, gender, bilingual status, speech sound production ability, phonological complexity, and PND. Conclusions Intraword variability was found to be lower in French than what has been reported in English, consistent with phonological differences between French and English. Our findings support those of other investigators in indicating that the factors influencing intraword variability are multiple and reflect sources at various levels in the speech processing system.

The Effect of Practice on Variability in Childhood Apraxia of Speech: A Multidimensional Analysis

Purpose Variability has been interpreted in differing ways according to context (e.g., development, speech impairment, and learning). A challenge arises when interpreting variability in the context of learning for children with speech impairment characterized by high movement variability, as in childhood apraxia of speech (CAS). The objective of this study is to investigate changes in variability in CAS with practice in comparison to patterns seen in children with non-CAS speech sound disorders (SSD) and typical development. Method Speech production variability was examined in 24 children (5-6 years of age) with CAS, non-CAS SSD, and typical development in production of nonwords of varied motoric complexity. Multidimensional analyses were performed using measures of token-to-token speech consistency (percent word consistency), acoustic variability (acoustic spatiotemporal index), and movement variability (lip aperture spatiotemporal index). Changes in variability were examined in each group of children by comparing the first half to the last half of nonword tokens in the same data collection session. The impact of token complexity on practice effects was also explored across groups of children. Results All children displayed increased speech consistency within this practice period (p = .01). Only children with CAS displayed increased movement variability following practice (p = .01). Differences in acoustic and kinematic variability were observed across complexity levels in all groups, though these did not interact with practice effects. Discussion These findings suggest that increased movement variability in children with CAS might be facilitating perceptual consistency. It is believed that this finding reflects an inefficient strategy adapted by children with CAS in the absence of motor-based cueing and feedback to guide speech performance with practice.

Early receptive and expressive lexicons and language and pre-literacy skills at 5;0 years - A longitudinal study

BACKGROUND

The long-term associations between early receptive/expressive lexical skills and later language/pre-literacy skills require clarification.

AIMS

To study the association between and predictive values of early receptive/expressive lexical skills and language/pre-literacy skills at 5;0 years, and to examine the language profiles at 5;0 years of children with weak receptive language/expressive lexical skills at 2;0 years.

PARTICIPANTS AND METHODS

The participants were 66 monolingual children. Their lexical skills were measured using the Finnish short-form version of the MacArthur-Bates Communicative Development Inventories at 1;6 and 2;0 years. Receptive language skills were measured at 2;0 years using the Reynell Developmental Language Scales III. A broader assessment at 5;0 years measured lexical, phonological, morphological and pre-literacy skills.

RESULTS

Significant associations between receptive/expressive lexical skills at 1;6 years and language and pre-literacy skills at 5;0 years were found. Both receptive language and expressive lexical development measured at 2;0 years were greatly and relatively evenly associated with language and pre-literacy skills at 5;0 years. Lexicon/language variables at 1;6 years and 2;0 years had statistically significant predictive values for general language and pre-literacy scores at 5;0 years. The best models that included early lexical predictors explained 20-34% of later language/literacy outcome. Weak skills at 2;0 years proposed vulnerability in language and pre-literacy skills at 5;0 years.

CONCLUSIONS

Language and pre-literacy skills at 5;0 years can to some extent be explained by early receptive language and/or expressive lexical development. Further assessment and/or follow-up is important for children who have had weak language/lexical skills at 2;0 years.

Variability across repeated productions in bilingual children speaking Jamaican Creole and English

PURPOSE

Previous work suggests that variability across repeated productions of the same word may be useful in diagnosing speech sound disorder (SSD) in bilingual children. However, there is debate over what level of variability in transcribed productions should be considered typical even in monolingual speech development. High variability in the input represents a factor that could promote increased production variability in bilinguals. For this reason, the current study examines transcription-based token-to-token variability in bilingual children speaking Jamaican Creole (JC) and English.

METHOD

Twenty-five bilingual children aged 3;4-5;1 and twenty-five monolingual children aged 2;9-4;1 from a previous study were recorded producing eleven items in three repetitions.

RESULT

Contrary to our hypothesis, bilingual children showed similar rates of token-to-token variability compared to the monolingual children. In a separate analysis of bilingual data across languages, bilingual children were more variable in JC compared to English productions.

CONCLUSION

The difference between language contexts suggests that creole languages, which exist on a usage continuum, may be associated with increased variability in production. Our findings suggest that token-to-token production variability may be of similar clinical utility for bilingual and monolingual populations.

Intra-word accuracy and consistency in Finnish-speaking children with speech sound disorder compared to their typically developing peers

This study examined intra-word accuracy and consistency in 32 preschool-aged Finnish-speaking children with speech sound disorder (SSD) compared to their typically developing (TD) age- and gender-matched peers. Accuracy and consistency of speech production were assessed by a picture-naming task repeated three times in one assessment session. Responses were classified into four categories: 1) consistently correct, 2) consistently incorrect, 3) variable with hits (when a child's variable responses included at least one matched with the adult target), and 4) variable with no hits (when responses included at least two different response types without the matched adult target). In addition, relationships between intra-word accuracy and consistency and children's receptive vocabulary knowledge and articulatory ability based on spontaneous speech samples were investigated. The findings showed that the children with SSD produced significantly more often 'consistently incorrect' and 'variable with no hits' responses than the TD children. There was a significant negative correlation between 'variable with no hits' responses and receptive vocabulary knowledge and articulatory abilities among the children with SSD. As intra-word accuracy and consistency has not previously been studied in Finnish children with SSD, the findings highlighted the need for drafting guidelines for assessment and intervention by paying close attention to high intra-word variability without correct word forms already from age three onwards.

Development and measurement of psychometric properties of the Persian test of speech consistency in children with typical development

The current research pursues the study of developing the Persian test of speech consistency and investigating speech consistency in normally developing children in Iran. After developing the Persian test of speech consistency, the obtained speech samples of 317 participants (163 girls and 154 boys) were analyzed. This test of consistency includes 27 items. Experts' consensus over the characteristics of the Persian test of speech consistency was above 85%. Different age groups had statistically significant differences for the mean scores of the variable responses (p < .001), consistent correct (p < .001), and consistent incorrect responses (p = .007) in the Persian test of speech consistency. Also, there was a high value for the inter-rater reliability (ICC = .88, p < .001) as well as the moderate value for the test-retest reliability (ICC = .89, p < .001). The Persian test of speech consistency is regarded as a reliable and valid scale for measuring the speech consistency in Persian-speaking children. Future studies are proposed to investigate the speech consistency in Persian-speaking children with various kinds of speech sound disorders.

Phonological development of Finnish speaking children at 3;6 and associations to previous and simultaneous lexical ability

Previous studies of Finnish children's phonological development focus mainly on children under 2;0. Earlier findings have suggested that phonological and lexical development are strongly associated at an early age. However, less is known about the longitudinal association. This study describes the phonological skills of Finnish-speaking children at 3;6 and compares them with early lexicon size at 2;0 and lexical ability at 3;6 (N = 67). The children's phonological development was measured using The Finnish Phonology Test. Lexical development was evaluated using the Finnish, long-form version of the Communicative Development Inventory at 2;0 and the Boston naming test at 3;6 At 3;6, all children mastered the vowels and diphthongs fully, and most of the children also mastered the consonants, with the exception of the phonemes/d/and/r/. Phonotactic skills had also been acquired well at this group level, although the word-medial and, especially, word-initial consonant clusters were still challenging. The percentage of phonemes correct was 95. Both paradigmatic and phonotactic skills at 3;6 were significantly associated with lexicon size at 2;0. In addition phonotactic skills correlated with naming ability at 3;6. Lexical development at 2;0 explained 21% of the variance in the phonological development at 3;6, whereas, the explaining value of simultaneous lexical skill was limited (9%). Present findings propose that associations between lexical and phonological skills weaken as phonological skills become more honed.

Speech Production Accuracy and Variability in Monolingual and Bilingual Children With Cochlear Implants: A Comparison to Their Peers With Normal Hearing

Purpose This study investigates consonant and vowel accuracy and whole-word variability (also called token-to-token variability or token-to-token inconsistency) in bilingual Spanish-English and monolingual English-speaking children with cochlear implants (CIs) compared to their bilingual and monolingual peers with normal hearing (NH). Method Participants were 40 children between 4;6 and 7;11 (years;months; M _age = 6;2), n = 10 each in 4 participant groups: bilingual Spanish-English with CIs, monolingual English with CIs, bilingual Spanish-English with NH, and monolingual English with NH. Spanish and English word lists consisting of 20 words of varying length were generated, and 3 productions of each word were analyzed for percent consonants correct, percent vowels correct, and the presence of any consonant and/or vowel variability. Results Children with CIs demonstrated lower accuracy and more whole-word variability than their peers with NH. There were no differences in rates of accuracy or whole-word variability between bilingual and monolingual children matched on hearing status, and bilingual children had lower accuracy and greater whole-word variability in English than in Spanish. Conclusions High rates of whole-word variability are prevalent in the speech of children with CIs even after many years of CI experience, and bilingual language exposure does not appear to negatively impact phonological development in children with CIs. Contributions to our understanding of underlying sources of speech production variability and clinical implications are discussed.

Intra-word consistency and accuracy in Finnish children aged 3-6 years

This study examined intra-word consistency and accuracy in typically developing Finnish children and their relation to children's vocabulary size and phonological skills. A total of 80 typically developing Finnish children aged 3;0 to 6;11 were asked to name 20 words three separate times during a single assessment session. Responses were classified into four categories: 1) consistently correct productions, 2) consistently incorrect productions, 3) variable productions with hits (variable productions including at least one matched adult target), and 4) variable productions with no hits. The results revealed that 5- and 6-year-old children produced significantly more often consistently correct responses than younger children. However, even for the 3- and 4-year old children the most frequent response type was consistently correct production. Between these two youngest age groups (3 and 4), the only significant difference was in consistently incorrect responses, which the 3-year-olds produced more often than the older children. There was a significant negative correlation between consistently incorrectly produced words and children's phonological skills, but no other relationships were found. The results indicate that when assessing children with speech sound disorder (SSD), Finnish clinicians need to take into account the fact that even 3-year-old typically developing children generally produce words correctly, either consistently or inconsistently.

Single word test for the assessment of speech sound production in Persian speaking children: Development, validity and reliability

OBJECTIVES

Single word tests are used frequently to determine clients' speech sound errors. These tools are user-friendly and popular for speech and language pathologists. The aim of this study was to design and validate a single word test for the assessment of speech sound production for Persian speaking children.

METHODS

The present study included two phases. In phase I, test material was developed. Psychometric properties were evaluated in phase II. In the next phase, 525 typically developing Persian-speaking children with the age range of 3-5 years old were studied. Statistical Package for the Social Sciences, version 24.0 (SPSS, Inc., Chicago, IL) was used for statistical analysis of this study. The significance level was set at (p < 0.05). Pilot study was performed by administrating the test on 25 typically developing children, construct validity: by administrating the test on 400 typically developing children and the comparison of performance of the children in 4 age groups (discriminative validity regarding age and by administration of this test and phonetic subtest of Persian version of diagnostic evaluation of articulation and phonology on 100 children (convergent validity)). Inter-rater reliability was performed by transcription and scoring of samples of 25 children and calculation of Intra Correlation Coefficient (ICC) was calculated. Test-retest was completed by administrating the test two times on 30 children with two weeks intervals. Internal consistency was achieved by the calculation of the correlation of the items of test.

RESULTS

The final version of the test includes 70 target words for assessment of the consonants in three positions, vowels in medial position and consonant clusters (CVCC). There was 80% or more than it for the percentage agreement between experts for the content validity. There wasn't any significant difference between experts' responses about items of the test. 4 pictures were revised based on children's responses for the pilot study. All of the reliability values (test-re test, internal consistency and inter-rater reliability) were higher than 0.85. There was a significant difference between the four age groups for the mean value of Persian single word test for speech sound production (p < 0.0001). There was a high correlation between the score of this instrument and the scores of participants in the Phonetic sub-test of the Persian version of Diagnostic evaluation of articulation and phonology(r = 0.934, p < 0.0001).

CONCLUSION

It seems that the Persian Speech sound Production Test is a reliable and valid tool that can be used to measure speech sound errors for Persian speaking children.

Stimulus Characteristics of Single-Word Tests of Children's Speech Sound Production

Purpose

This clinical focus article provides readers with a description of the stimulus characteristics of 12 popular tests of speech sound production.

Method

Using significance testing and descriptive analyses, stimulus items were compared in terms of the number of opportunities for production of all consonant singletons, clusters, and rhotic and nonrhotic vowels of Standard American English; phonetic/phonological and structural complexity; and the presence of bound morphemes.

Results

The tests varied widely in terms of the number of opportunities for production of consonant singletons, clusters, and rhotic and nonrhotic vowels. Most of the tests included only 1 opportunity, scored or unscored, to produce a majority of the consonant singletons in each word position. Only 3 of the tests included stimulus items with 3-element clusters. The majority contained limited opportunities to produce 3- or 4-syllable stimulus items. The tests provided sufficient opportunities for production of most vowels, although most did not score vowels. The tests differed significantly in the complexity of their stimulus items. Most, however, contained a negligible number of items that, with the addition of a bound morpheme, resulted in a word-final cluster.

Conclusion

Most of the tests elicit an inadequate sample with which to conduct a comprehensive phonological analysis.

Gradient perception of children's productions of /s/ and /θ/: A comparative study of rating methods

Past studies have shown incontrovertible evidence for the existence of covert contrasts in children's speech, i.e. differences between target productions that are nonetheless transcribed with the same phonetic symbol. Moreover, there is evidence that these are relevant to forming prognoses and tracking progress in children with speech sound disorder. A challenge remains to determine the most efficient and reliable methods for assessing covert contrasts. This study investigates how readily listeners can identify covert contrasts in children's speech when using a continuous rating scale in the form of a visual analogue scale (VAS) to denote children's productions. Individual listeners' VAS responses were found to correlate statistically significantly with a variety of continuous measures of children's production accuracy, including judgements of binary accuracy pooled over a large set of listeners. These findings reinforce the growing body of evidence that VAS judgements are potentially useful clinical measures of covert contrast.

Comprehensive Assessment of Speech Sound Production in Preschool Children

This paper describes a comprehensive speech sound assessment for preschool children suspected of having a speech sound disorder (SSD). Recommended components include standardized single-word testing, additional single-word testing, connected speech sampling, phonological analyses, stimulability testing, and inconsistency testing. While data collection and some cursory analyses take place during the evaluation session, allowing the speech-language pathologist (SLP) to share key information with the parents/caregivers, much of the in-depth analysis takes place later. Since most preschool children's SSDs are phonological in nature, a phonological approach to analysis, target selection, and treatment is required. Two examples of phonological analyses, a place-voice-manner (PVM) analysis and an error pattern analysis, are discussed. Both allow the SLP to identify patterns of difficulty in the child's speech with regards to the place, voicing, and/or manner characteristics of target consonants. Phonological analyses can be performed using the child's single-word and connected speech samples. This information, along with the results from the stimulability and inconsistency testing, will allow the SLP to gain a complete picture of the child's speech sound abilities and difficulties, determine prognosis for change, and identify treatment targets.

Lexical Considerations in the Treatment of Speech Sound Disorders in Children

The interaction between lexical and phonological development has been the focus of a growing body of research. Findings suggest that phonological ability influences word learning and that certain characteristics of words influence how words are produced by children. This article summarizes research findings regarding the effects of word frequency, phonological neighborhood density (PND), and phonotactic probability (PP) on phonological development, and describes how these factors have been manipulated to influence phonological learning in the treatment of speech sound disorder in children. Clinical applications and ideas for considering lexical factors in the selection of target words for treatment are provided.