EPG research and therapy: further developments.

Electropalatography (EPG) has been used in the past 50 years for studying the patterns of contact between the tongue and the palate during speech production in typical speakers and those with speech disorders due to different causes. At the 7th EPG Symposium in Japan that was held online on 24 January 2021 (see: https://epg-research.sakura.ne.jp/), a panel of invited experts discussed their views regarding further developments and application of the technique. This paper provides a summary of this discussion. EPG offers information on articulation which cannot be replaced by other instrumental measures of speech. Identified areas for further hardware development are thinner EPG plates, better dental and palatal coverage, wireless connectivity, and sensors that provide additional articulatory information (e.g. tongue pressure, tongue-palate distance). EPG can serve as a resource for teaching speech disorders and phonetics. Furthermore, EPG therapy can be combined with telepractice in the speech therapy of clients with speech disorders.

Electropalatography (EPG) activities in Japan and the impact of the COVID-19 pandemic on EPG research and therapy: A report of presentations at the 7th EPG Symposium.

BACKGROUND: At the 7th Electropalatography Symposium in Japan, held online on the 24 January 2021, a few speakers were invited to talk about how the COVID-19 pandemic had impacted their research and/or speech therapy that involved the use of electropalatography (EPG) as well as the procedures adopted in order to continue their work in a safe manner. The information on protective measures when using instrumental techniques in speech research and therapy may be useful for colleagues in research and the clinic. AIMS: The primary aims are: (1) to find out whether there are any published recommendations regarding protective measures for using EPG in research and clinic settings; (2) to discuss the impact of the pandemic and the corresponding restrictions and general protective measures directed (or advised) by local government and professional bodies at each stage of EPG work; and (3) to share experiences in using modified procedures for face-to-face EPG therapy sessions and combined EPG teletherapy. In addition, a brief overview of EPG and a summary of EPG research and clinical activities in Japan presented by one of the symposium organizers at the symposium are included. METHODS & PROCEDURES: A review of the literature regarding protective measures recommended for using EPG for speech assessment and treatment or research, supplemented by a discussion of our own experiences. MAIN CONTRIBUTION: The literature review showed that there are no guidelines regarding protective measures for using EPG, but there is some advice regarding speech recording using microphones. Most published articles related to speech and language therapy (SLT) service during COVID-19 are about telepractice or general clinical guidelines for face-to-face speech therapy sessions. The protective measures for using EPG developed based on the general guidelines recommended by local government and professional bodies (e.g., using visors, transparent acrylic board) were described. Using EPG in telepractice was discussed as well. CONCLUSIONS: It has been challenging to continue EPG research and therapy during the pandemic. In order to deal with this crisis, available knowledge regarding infection control and recommendations from local government and professional bodies were applied to design methods and procedures that allowed EPG research and therapy to continue. WHAT THIS PAPER ADDS: What is already known on the subject There are general protective measures recommended by local government and professional bodies regarding speech therapy sessions (e.g., using personal protective equipment (PPE), social distancing), but little is known about the measures for using instrumental techniques in speech research and therapy, particularly EPG. The equipment of each instrumental technique is different, so measures that are appropriate for one may not be suitable for others. Hence, specific recommendations are needed for EPG. What this paper adds to existing knowledge This paper provides pointers to information about recommendations regarding protective measures for speech research and therapy, supplemented with suggestions specific to EPG provided by experienced users based on actual experience. What are the potential or actual clinical implications of this work? In evaluating the impact of the COVID-19 pandemic on EPG research and therapy, an analytical approach was taken to break down the steps involved in carrying out those activities, and the challenges we faced and the possible alternatives for completing the tasks were discussed. A similar approach can be applied to evaluate other aspects of speech therapy service.

Intelligibility in Down syndrome: Effect of measurement method and listener experience.

BACKGROUND: Speech intelligibility is a global indicator of the severity of a speech problem. It is a measure that has been used frequently in research and clinical assessment of speech. Previous studies have shown that factors, such as measurement method and listener experience, can influence speech intelligibility scores. However, these factors of speech intelligibility assessment have not yet been investigated in people with Down syndrome (DS). AIMS: To compare the speech intelligibility scores in speakers with DS measured using two methods: orthographic transcription and visual analogue scale (VAS), by two groups of listeners, experienced listeners and naïve listeners. Also, to examine the relationship across the four sets of speech intelligibility scores by means of correlational analysis. METHODS & PROCEDURES: A total of 30 adolescents and adults with DS read or repeated 12 sentences from a standardized test of intelligibility for adults with dysarthria. Each sentence was saved as a separate sound file and the 360 sentences were divided to form eight sets of stimuli. A total of 32 adults (16 experienced and 16 naïve) served as listeners of speech intelligibility. Each listener heard a single set of sentences and independently estimated the level of intelligibility for each sentence using a VAS in one task and wrote down the words perceived (i.e., orthographic transcription) in another task. The order of the two tasks was counterbalanced across listeners and the tasks were completed at least 1 week apart. OUTCOMES & RESULTS: Repeated-measures analysis of variance (ANOVA), confirmed by mixed-methods analysis, showed that the scores obtained using orthographic transcription were significantly higher than those obtained using VAS; and the experienced listeners' scores were significantly higher than the naïve listeners' scores. Spearman rank correlation analysis showed that the four sets of scores across all conditions were strongly positively correlated with each other. CONCLUSIONS & IMPLICATIONS: Listeners, both experienced and naïve, may udge speech in DS differently when using orthographic transcription versus VAS as the method of measurement. In addition, experienced listeners can judge speech intelligibility differently compared with listeners who are less exposed to unclear speech, which may not represent 'real-world' functional communicative ability. Speech and language therapists should be aware of the effect of these factors when measuring intelligibility scores and direct comparison of scores obtained using different procedures and by different groups of listeners is not recommended. What this paper adds What is already known on the subject Previous research on other clinical groups (e.g., Parkinson's disease) has shown that speech intelligibility scores can vary across different measurement methods and when judged by listeners with different experience. However, these factors have not yet been investigated in people with DS. What this paper adds to existing knowledge Similar to the findings reported for other clinical groups, using an impressionistic measurement method, such as VAS, can result in different speech intelligibility scores compared with scores obtained from orthographic transcription in speakers with DS. Furthermore, experienced listeners can perceive intelligibility as better compared with naïve (untrained) listeners for this group. What are the potential or actual clinical implications of this work? When measuring speech intelligibility, speech and language therapists should be aware that scores obtained using orthographic transcription can be higher than those obtained using VAS. They should also be aware that their increased exposure to hearing atypical speech may cause them to judge the speech difficulty as less severe and lead to an inaccurate representation of speech performance. Speech and language therapists should consider these factors when interpreting assessment results and especially when using intelligibility measures for treatment outcomes.

Perceptual and acoustic evaluation of speech production in Down syndrome: A case series.

People with Down syndrome (DS) can experience difficulties with speech production that can impact on speech intelligibility. In previous research, both perceptual and acoustic analysis has shown that people with DS can have difficulties with speech production in the areas of respiration, phonation, articulation, resonance and prosody. However, these studies have investigated various aspects of speech production separately. No study has examined all components of speech production in one single study and considered how these components, if impaired, may impact on speech intelligibility in DS. This paper presents the data of three male speakers with DS and three age- and gender-matched controls as a case series. The participants' speech samples were analysed using a number of perceptual and acoustic parameters, across the major components of speech production - respiration, phonation, articulation, resonance, and prosody. Results showed that different areas of speech production were affected in each participant, to different extents. The main perceptual difficulties included poor voice quality, monopitch, and monoloudness. Acoustic findings showed a higher mean F0, lower harmonics-to-noise ratio and longer voice onset times. These preliminary findings show that people with DS can present with mixed profiles of speech production that can affect speech intelligibility. When assessing speech production in DS, clinicians need to evaluate all components of speech production and consider how they may be impacting intelligibility.

Tongue-palate contact for nasal versus oral stops in speakers with repaired cleft palate.

Most previous studies of speech disorders associated with cleft palate have reported a higher incidence of errors for oral stops, fricatives and affricates compared to nasal stops. However, the results of a recent ultrasound study have raised the possibility that errors affecting nasal consonants might not be as rare as originally thought. A review of the electropalatography (EPG) literature on cleft palate speech has also shown that atypical tongue-palate contact patterns can occur during nasal consonants and that nasal and oral stops are often produced with similar atypical lingual gestures. Therefore, this study investigated the production of nasal stops (/n/and/ŋ/) and the homorganic oral stops (/t/,/d/and/k/,/ɡ/respectively) in eight children with repaired cleft palate using perceptual judgements and evaluation of tongue-palate contact patterns. Results of the perceptual judgements support the findings in the literature that there was a higher per cent phoneme correct for the alveolar nasal (about 90%) than for the oral stops (60-70%). However, there was a low per cent phoneme correct for the velar nasal (about 50%) and the per cent correct as determined by the EPG data was lower than those based on perceptual judgements. Two children showed similar atypical articulatory gestures for the oral and nasal alveolar stops. We discuss the possibility that the nasal errors may be of phonemic as opposed to phonetic origin. The results underscore the importance of considering the phonological dimension of production when assessing the speech of children in this clinical group.

Parent-mediated interventions for promoting communication and language development in young children with Down syndrome.

BACKGROUND: Communication and language development are areas of particular weakness for young children with Down syndrome. Caregivers' interaction with children influences language development, so many early interventions involve training parents how best to respond to their children and provide appropriate language stimulation. Thus, these interventions are mediated through parents, who in turn are trained and coached in the implementation of interventions by clinicians. As the interventions involve a considerable commitment from clinicians and families, we undertook this review to synthesise the evidence of their effectiveness. OBJECTIVES: To assess the effects of parent-mediated interventions for improving communication and language development in young children with Down syndrome. Other outcomes are parental behaviour and responsivity, parental stress and satisfaction, and children's non-verbal means of communicating, socialisation and behaviour. SEARCH METHODS: In January 2018 we searched CENTRAL, MEDLINE, Embase and 14 other databases. We also searched three trials registers, checked the reference lists of relevant reports identified by the electronic searches, searched the websites of professional organizations, and contacted their staff and other researchers working in the field to identify other relevant published, unpublished and ongoing studies. SELECTION CRITERIA: We included randomised controlled trials (RCTs) and quasi-RCTs that compared parent-mediated interventions designed to improve communication and language versus teaching/treatment as usual (TAU) or no treatment or delayed (wait-listed) treatment, in children with Down syndrome aged between birth and six years. We included studies delivering the parent-mediated intervention in conjunction with a clinician-mediated intervention, as long as the intervention group was the only group to receive the former and both groups received the latter. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methodological procedures for data collection and analysis. MAIN RESULTS: We included three studies involving 45 children aged between 29 months and six years with Down syndrome. Two studies compared parent-mediated interventions versus TAU; the third compared a parent-mediated plus clinician-mediated intervention versus a clinician-mediated intervention alone. Treatment duration varied from 12 weeks to six months. One study provided nine group sessions and four individualised home-based sessions over a 13-week period. Another study provided weekly, individual clinic-based or home-based sessions lasting 1.5 to 2 hours, over a six-month period. The third study provided one 2- to 3-hour group session followed by bi-weekly, individual clinic-based sessions plus once-weekly home-based sessions for 12 weeks. Because of the different study designs and outcome measures used, we were unable to conduct a meta-analysis.We judged all three studies to be at high risk of bias in relation to blinding of participants (not possible due to the nature of the intervention) and blinding of outcome assessors, and at an unclear risk of bias for allocation concealment. We judged one study to be at unclear risk of selection bias, as authors did not report the methods used to generate the random sequence; at high risk of reporting bias, as they did not report on one assessed outcome; and at high risk of detection bias, as the control group had a cointervention and only parents in the intervention group were made aware of the target words for their children. The sample sizes of each included study were very small, meaning that they are unlikely to be representative of the target population.The findings from the three included studies were inconsistent. Two studies found no differences in expressive or receptive language abilities between the groups, whether measured by direct assessment or parent reports. However, they did find that children in the intervention group could use more targeted vocabulary items or utterances with language targets in certain contexts postintervention, compared to those in the control group; this was not maintained 12 months later. The third study found gains for the intervention group on total-language measures immediately postintervention.One study did not find any differences in parental stress scores between the groups at any time point up to 12 months postintervention. All three studies noted differences in most measures of how the parents talked to and interacted with their children postintervention, and in one study most strategies were maintained in the intervention group at 12 months postintervention. No study reported evidence of language attrition following the intervention in either group, while one study found positive outcomes on children's socialisation skills in the intervention group. One study looked at adherence to the treatment through attendance data, finding that mothers in the intervention group attended seven out of nine group sessions and were present for four home visits. No study measured parental use of the strategies outside of the intervention sessions.A grant from the Hospital for Sick Children Foundation (Toronto, Ontario, Canada) funded one study. Another received partial funding from the National Institute of Child Health and Human Development and the Department of Education in the USA. The remaining study did not specify any funding sources.In light of the serious limitations in methodology, and the small number of studies included, we considered the overall quality of the evidence, as assessed by GRADE, to be very low. This means that we have very little confidence in the results, and further research is very likely to have an important impact on our confidence in the estimate of treatment effect. AUTHORS' CONCLUSIONS: There is currently insufficient evidence to determine the effects of parent-mediated interventions for improving the language and communication of children with Down syndrome. We found only three small studies of very low quality. This review highlights the need for well-designed studies, including RCTs, to evaluate the effectiveness of parent-mediated interventions. Trials should use valid, reliable and similar measures of language development, and they should include measures of secondary outcomes more distal to the intervention, such as family well-being. Treatment fidelity, in particular parental dosage of the intervention outside of prescribed sessions, also needs to be documented.

The dynamics of voiceless sibilant fricative production in children between 7 and 13 years old: An ultrasound and acoustic study.

This study reports on dynamic tongue shape and spectral characteristics of sibilant fricatives /s/ and /ʃ/ in Scottish English speaking children aged between 7 and 13 years old. The sequences /əCa/ and /əCi/ were produced by 40 children, with ten participants in each age group, and two-year intervals between successive groups. Productions of the same sequences by ten adults were used for comparison with the children's data. Quantitative dynamic analyses were carried out on spectral information and on ultrasound imaging data on tongue shape. All age groups differentiated between the two consonants in the fricative centroid and in tongue shape. Vowel-on-consonant effects showed consonant-specific patterns across age groups without a consistent increase or decrease in the extent of coarticulation with increasing age. The extent of discriminability between the two fricatives increased with age on both acoustic and articulatory measures. Younger speakers were generally more variable than older speakers. Complementary findings from the centroid and tongue shape measures suggest that age-related differences are due to the ongoing maturation of controlling the tongue in coordination with other articulators, particularly the jaw, throughout childhood.

Tongue-Palate Contact Timing during /s/ and /z/ in English.

Although numerous studies have investigated supraglottal strategies for signalling voicing in fricatives, there is still no agreement about the precise characteristics of tongue-to-palate contact timing during voiced as opposed to voiceless fricatives. In this study we use electropalatography (EPG) to investigate articulatory and coarticulatory characteristics of tongue-to-palate contact timing during /s/ and /z/ in English. Five typically speaking participants, speakers of Southern British English, produced 500 trochaic words containing the intervocalic alveolar fricatives /s/ or /z/. The time between the start of the frication and the maximum contact at the place of articulation was expressed as a percentage of each fricative's total duration (time to target, TT).This measure was used to analyse articulatory and coarticulatory timing during /s/ and /z/. Data for absolute timing were also presented. The results showed that the time between the start of the frication and the maximum contact point was longer for /s/ than for /z/. This difference was consistent across speakers but was not significant for all of them. The results of the coarticulatory effects showed that the influence of vowel context on TT values for /s/ and /z/ did not differ significantly, but there was a tendency for /z/ to be more resistant to coarticulation effects than /s/.

The effect of different speaker accents on sentence comprehension in children with speech sound disorder.

There is substantial evidence that a speaker's accent, specifically an unfamiliar accent, can affect the listener's comprehension. In general, this effect holds true for both adults and children as well as those with typical and impaired language. Previous studies have investigated the effect of different accents on individuals with language disorders, but children with speech sound disorders (SSDs) have received little attention. The current study aims to learn more about the ability of children with SSD to process different speaker accents. Fifteen children with SSD aged between 4;01 and 5;11 years, and 16 typically developing children matched on language ability, age, socioeconomic status, gender and cognitive ability participated in the current study. A sentence comprehension task was carried out with each child, requiring them to follow instructions of increasing length spoken in three different accents - (i) a local Irish (Cork) accent, (ii) a regional North American accent and (iii) a non-native Indian English accent. Results showed no significant group difference and speaker accent did not significantly impact children's performance on the task. The results are discussed in relation to factors that influence accent comprehension, and their implications for children's underlying phonological representations.

Children's Attitudes Toward Peers With Unintelligible Speech Associated With Cleft Lip and/or Palate.

OBJECTIVE: The objective of this study was to investigate whether reduced speech intelligibility in children with cleft palate affects social and personal attribute judgments made by typically developing children of different ages. DESIGN: The study (1) measured the correlation between intelligibility scores of speech samples from children with cleft palate and social and personal attribute judgments made by typically developing children based on these samples and (2) compared the attitude judgments made by children of different ages. Participants A total of 90 typically developing children, 30 in each of three age groups (7 to 8 years, 9 to 10 years, and 11 to 12 years). OUTCOME MEASURES: Speech intelligibility scores and typically developing children's attitudes were measured using eight social and personal attributes on a three-point rating scale. RESULTS: There was a significant correlation between the speech intelligibility scores and attitude judgments for a number of traits: "sick-healthy" as rated by the children aged 7 to 8 years, "no friends-friends" by the children aged 9 to 10 years, and "ugly-good looking" and "no friends-friends" by the children aged 11 to 12 years. Children aged 7 to 8 years gave significantly lower ratings for "mean-kind" but higher ratings for "shy-outgoing" when compared with the other two groups. CONCLUSIONS: Typically developing children tended to make negative social and personal attribute judgments about children with cleft palate based solely on the intelligibility of their speech. Society, educators, and health professionals should work together to ensure that children with cleft palate are not stigmatized by their peers.

Electropalatographic (EPG) evidence of covert contrasts in disordered speech.

The phenomenon of covert contrasts has intrigued researchers and clinicians since it was first identified using instrumental data nearly 50 years ago. The term covert contrast refers to phonological contrasts that listeners do not readily identify and which therefore pass unrecorded in transcription-based studies. Covert contrasts are viewed as significant from theoretical and clinical perspectives. Although influential, there are relatively few instrumental studies of covert contrasts. The studies that do exist are limited to revealing contrasts that manifest in specific phonetic parameters or phonological processes. However, recent studies have provided convincing new evidence that covert contrasts are likely to be widespread in child speech. The purpose of this article is threefold: to review electropalatography (EPG) studies of covert contrasts; to provide EPG examples from the speech of individuals with speech disorders and to discuss the implications in child speech.

Using ultrasound tongue imaging to identify covert contrasts in children's speech.

Ultrasound tongue imaging has become a promising technique for detecting covert contrasts, due to the developments in data analysis methods that allow for processing information on tongue shape from young children. An important feature concerning analyses of ultrasound data from children who are likely to produce covert contrasts is that the data are likely to be collected without head-to-transducer stabilisation, due to the speakers' age. This article is a review of the existing methods applicable in analysing data from non-stabilised recordings. The article describes some of the challenges of ultrasound data collection from children, and analysing these data, as well as possible ways to address those challenges. Additionally, there are examples from typical and disordered productions featuring covert contrasts, with illustrations of quantifying differences in tongue shape between target speech sounds.

Children's comprehension of an unfamiliar speaker accent: a review.

BACKGROUND: The effect of speaker accent on listeners' comprehension has become a key focus of research given the increasing cultural diversity of society and the increased likelihood of an individual encountering a clinician with an unfamiliar accent. AIMS: To review the studies exploring the effect of an unfamiliar accent on language comprehension in typically developing (TD) children and in children with speech and language difficulties. This review provides a methodological analysis of the relevant studies by exploring the challenges facing this field of research and highlighting the current gaps in the literature. METHODS & PROCEDURES: A total of nine studies were identified using a systematic search and organized under studies investigating the effect of speaker accent on language comprehension in (1) TD children and (2) children with speech and/or language difficulties. MAIN CONTRIBUTION: This review synthesizes the evidence that an unfamiliar speaker accent may lead to a breakdown in language comprehension in TD children and in children with speech difficulties. Moreover, it exposes the inconsistencies found in this field of research and highlights the lack of studies investigating the effect of speaker accent in children with language deficits. CONCLUSIONS & IMPLICATIONS: Overall, research points towards a developmental trend in children's ability to comprehend accent-related variations in speech. Vocabulary size, language exposure, exposure to different accents and adequate processing resources (e.g. attention) seem to play a key role in children's ability to understand unfamiliar accents. This review uncovered some inconsistencies in the literature that highlight the methodological issues that must be considered when conducting research in this field. It explores how such issues may be controlled in order to increase the validity and reliability of future research. Key clinical implications are also discussed.

Non-speech oral motor treatment for children with developmental speech sound disorders.

BACKGROUND: Children with developmental speech sound disorders have difficulties in producing the speech sounds of their native language. These speech difficulties could be due to structural, sensory or neurophysiological causes (e.g. hearing impairment), but more often the cause of the problem is unknown. One treatment approach used by speech-language therapists/pathologists is non-speech oral motor treatment (NSOMT). NSOMTs are non-speech activities that aim to stimulate or improve speech production and treat specific speech errors. For example, using exercises such as smiling, pursing, blowing into horns, blowing bubbles, and lip massage to target lip mobility for the production of speech sounds involving the lips, such as /p/, /b/, and /m/. The efficacy of this treatment approach is controversial, and evidence regarding the efficacy of NSOMTs needs to be examined. OBJECTIVES: To assess the efficacy of non-speech oral motor treatment (NSOMT) in treating children with developmental speech sound disorders who have speech errors. SEARCH METHODS: In April 2014 we searched the Cochrane Central Register of Controlled Trials (CENTRAL), Ovid MEDLINE (R) and Ovid MEDLINE In-Process & Other Non-Indexed Citations, EMBASE, Education Resources Information Center (ERIC), PsycINFO and 11 other databases. We also searched five trial and research registers, checked the reference lists of relevant titles identified by the search and contacted researchers to identify other possible published and unpublished studies. SELECTION CRITERIA: Randomised and quasi-randomised controlled trials that compared (1) NSOMT versus placebo or control; and (2) NSOMT as adjunctive treatment or speech intervention versus speech intervention alone, for children aged three to 16 years with developmental speech sound disorders, as judged by a speech and language therapist. Individuals with an intellectual disability (e.g. Down syndrome) or a physical disability were not excluded. DATA COLLECTION AND ANALYSIS: The Trials Search Co-ordinator of the Cochrane Developmental, Psychosocial and Learning Problems Group and one review author ran the searches. Two review authors independently screened titles and abstracts to eliminate irrelevant studies, extracted data from the included studies and assessed risk of bias in each of these studies. In cases of ambiguity or information missing from the paper, we contacted trial authors. MAIN RESULTS: This review identified three studies (from four reports) involving a total of 22 children that investigated the efficacy of NSOMT as adjunctive treatment to conventional speech intervention versus conventional speech intervention for children with speech sound disorders. One study, a randomised controlled trial (RCT), included four boys aged seven years one month to nine years six months - all had speech sound disorders, and two had additional conditions (one was diagnosed as "communication impaired" and the other as "multiply disabled"). Of the two quasi-randomised controlled trials, one included 10 children (six boys and four girls), aged five years eight months to six years nine months, with speech sound disorders as a result of tongue thrust, and the other study included eight children (four boys and four girls), aged three to six years, with moderate to severe articulation disorder only. Two studies did not find NSOMT as adjunctive treatment to be more effective than conventional speech intervention alone, as both intervention and control groups made similar improvements in articulation after receiving treatments. One study reported a change in postintervention articulation test results but used an inappropriate statistical test and did not report the results clearly. None of the included studies examined the effects of NSOMTs on any other primary outcomes, such as speech intelligibility, speech physiology and adverse effects, or on any of the secondary outcomes such as listener acceptability.The RCT was judged at low risk for selection bias. The two quasi-randomised trials used randomisation but did not report the method for generating the random sequence and were judged as having unclear risk of selection bias. The three included studies were deemed to have high risk of performance bias as, given the nature of the intervention, blinding of participants was not possible. Only one study implemented blinding of outcome assessment and was at low risk for detection bias. One study showed high risk of other bias as the baseline characteristics of participants seemed to be unequal. The sample size of each of the included studies was very small, which means it is highly likely that participants in these studies were not representative of its target population. In the light of these serious limitations in methodology, the overall quality of the evidence provided by the included trials is judged to be low. Therefore, further research is very likely to have an important impact on our confidence in the estimate of treatment effect and is likely to change the estimate. AUTHORS' CONCLUSIONS: The three included studies were small in scale and had a number of serious methodological limitations. In addition, they covered limited types of NSOMTs for treating children with speech sound disorders of unknown origin with the sounds /s/ and /z/. Hence, we judged the overall applicability of the evidence as limited and incomplete. Results of this review are consistent with those of previous reviews: Currently no strong evidence suggests that NSOMTs are an effective treatment or an effective adjunctive treatment for children with developmental speech sound disorders. Lack of strong evidence regarding the treatment efficacy of NSOMTs has implications for clinicians when they make decisions in relation to treatment plans. Well-designed research is needed to carefully investigate NSOMT as a type of treatment for children with speech sound disorders.

Electropalatography for Older Children and Adults with Residual Speech Errors.

Most residual speech errors (RSEs) involve abnormal positioning or movement of the tongue. However, it is not possible under normal circumstances to view directly the actions of the tongue during production of these distorted articulations. The visually inaccessible location of the tongue can often make precise diagnosis difficult in cases of RSEs, and intervention can be a particular challenge for clinicians when speech errors persist in older children and adults. Electropalatography (EPG) is a technique that can provide objective and clinically relevant data about details of tongue articulation during speech. Furthermore, biofeedback with EPG offers the possibility of an effective intervention for RSEs. This tutorial provides an overview of EPG and describes how the technique can contribute to our knowledge and treatment of abnormal tongue-palate contact in older children and adults with RSEs. An illustrative case study of a child with RSEs affecting fricatives and affricates is included.

Lateral bracing of the tongue during the onset phase of alveolar stops: an EPG study.

Although raising the sides of the tongue to form a seal with the palate and upper teeth--lateral bracing--plays a key role in controlling airflow direction, providing overall tongue stability and building up oral pressure during alveolar consonant production, details of this articulatory gesture remain poorly understood. This study examined the dynamics of lateral bracing during the onset of alveolar stops /t/, /d/, /n/ produced by 15 typical English-speaking adults using electropalatography. Percent tongue palate contact in the lateral regions over a 150-ms period from the preceding schwa to stop closure was measured. Rapid rising of the sides of the tongue from the back towards the front during the 50-ms period before closure was observed, with oral stops showing significantly more contact than nasal stops. This feature corresponds to well-documented formant transitions detectable from acoustic analysis. Possible explanations for increased contact for oral stops and clinical implications are discussed.

Quantifying lingual coarticulation using ultrasound imaging data collected with and without head stabilisation.

Previous studies reporting the use of ultrasound tongue imaging with clinical populations have generally provided qualitative information on tongue movement. Meaningful quantitative measures for use in the clinic typically require the speaker's head to be stabilised in relation to a transducer, which may be uncomfortable, and unsuitable for young children. The objective of this study was to explore the applicability of quantitative measurements of stabilisation-free tongue movement data, by comparing ultrasound data collected from 10 adolescents, with and without head stabilisation. Several measures of tongue shape were used to quantify coarticulatory influence from two contrasting vowels on four different consonants. Only one of the measures was completely unaffected by the stabilisation condition for all the consonants. The study also reported cross-consonant differences in vowel-related coarticulatory effects. The implications of the findings for the theory of coarticulation and for potential applications of stabilisation-free tongue curve measurements in clinical studies are discussed.

Preschool children's performance on Profiling Elements of Prosody in Speech-Communication (PEPS-C).

Profiling Elements of Prosody in Speech-Communication (PEPS-C) has not been used widely to assess prosodic abilities of preschool children. This study was therefore aimed at investigating typically developing 4-year-olds' performance on PEPS-C. PEPS-C was presented to 30 typically developing 4-year-olds recruited in southern Ireland. Children were judged to have completed the test if they produced analysable responses to >95% of the items. The children's scores were compared with data from typically developing 5-6-year-olds. The majority (83%) of 4-year-olds were able to complete the test. The children scored at chance or weak ability levels on all subtests. The 4-year-olds had lower scores than 5-6-year-olds in all subtests, apart from one, with the difference reaching statistical significance in 8 out of 12 subtests. The results indicate that PEPS-C could be a valuable tool for assessing prosody in young children with typical development and some groups of young children with communication disorders.

Tongue-palate contact of perceptually acceptable alveolar stops.

Increased tongue-palate contact for perceptually acceptable alveolar stops has been observed in children with speech sound disorders (SSD). This is a retrospective study that further investigated this issue by using quantitative measures to compare the target alveolar stops /t/, /d/ and /n/ produced in words by nine children with SSD (20 tokens of /t/, 13 /d/ and 11 /n/) to those produced by eight typical children (32 /t/, 24 /d/ and 16 /n/). The results showed that children with SSD had significantly higher percent contact than the typical children for target /t/; the difference for /d/ and /n/ was not significant. Children with SSD generally showed more contact in the posterior central area of the palate than the typical children. The results suggested that broader tongue-palate contact is a general articulatory feature for children with SSD and its differential effect on error perception might be related to the different articulatory requirements.