Effectiveness of speech therapy in adults with intellectual disabilities

The potential impact of literacy intervention on speech sound production in students with intellectual disability and communication difficulties

A small body of research and reports from educational and clinical practice suggest that teaching literacy skills may facilitate the development of speech sound production in students with intellectual disabilities (ID). However, intervention research is needed to test the potential connection. This study aimed to investigate whether twelve weeks of systematic, digital literacy intervention enhanced speech sound production in students with ID and communication difficulties. A sample of 121 students with ID were assigned to four different groups: phonics-based, comprehension-based, a combination with both phonics- and comprehension-based intervention and a comparison group with teaching-as-usual. Speech sound production was assessed before and after the intervention. The results on the data without the imputed variable suggested a significant positive effect of systematic, digital literacy interventions on speech sound production. However, results from sensitivity analyses with imputed missing data was more ambiguous, with the effect only approaching significance (ps = .05-.07) for one of the interventions. Nonetheless, we tentatively suggest that systematic, digital literacy intervention could support speech development in students with ID and communication difficulties. Future research should be done to confirm and further elucidate the functional mechanisms of this link, so that we may have a better understanding and can improve instruction and the pivotal abilities of speech and reading.

Hearing Loss Diagnosis and Management in Adults with Intellectual and Developmental Disabilities

Hearing loss is a common concern in patients with intellectual and developmental disabilities (IDD), and early detection and intervention are crucial to prevent negative impacts on communication, cognition, socialization, safety, and mental health. Despite a lack of the literature specifically focused on hearing loss in adults with IDD, there is a substantial body of research demonstrating the prevalence of hearing loss in this population. This literature review examines the diagnosis and management of hearing loss in adult patients with IDD, with a focus on primary care considerations. Primary care providers must be aware of the unique needs and presentations of patients with IDD to ensure appropriate screening and treatment. This review highlights the importance of early detection and intervention, as well as the need for further research to guide clinical practice in this patient population.

Positive effects of the Beatalk technique on speech characteristics of young adults with intellectual disability

Background: The Beatalk technique is a speech therapy method, based on human beatboxing, involving intense, rapid repetitions of speech-like sounds. The goals of the current feasibility study were to test its effect in enhancing articulation accuracy and voice measures in a small group of adults with intellectual disability (ID), using a wide range of measures of verbal communication, and to refine the treatment protocol. Methods: A group pre-test-post-test experimental design was used (n = 12). Treatment consisted of ten weekly group sessions of 40 min, each followed by two self-practice sessions. Changes in speech intelligibility, voice, and communication skills were assessed. Results: The findings indicate significant improvements in speech production and intelligibility measures (Percentage of Consonant Correct, and staff-member intelligibility scores), voice measures (vocal loudness, Harmonic-Noise-Ratio, shimmer, and jitter) and staff-member communication scores. Implications: These results extend our understanding of the effects of the Beatalk technique, and suggest that it may have potential as an effective intervention for adults with ID. As the experimental design is limited in its ability to yield strong conclusions, further controlled studies are required.

Smart speaker devices can improve speech intelligibility in adults with intellectual disability

BACKGROUND

Successful communication is vital to quality of life. One group commonly facing speech and communication difficulties is individuals with intellectual disability (ID). A novel route to encourage clear speech is offered by mainstream smart speakers (e.g., Amazon Alexa and Google Home). Smart speakers offer four factors important for learning: reward immediacy, spaced practice, autonomy/intrinsic motivation and reduced social barriers. Yet the potential of smart speakers to improve speech intelligibility has not been explored before.

AIMS

To determine whether providing individuals with intellectual disabilities with smart speaker devices improved ratings of speech intelligibility for (1) phrases related to device use and (2) unrelated words via a semi-randomized controlled trial.

METHODS & PROCEDURES

In a semi-randomized controlled trial, an intervention group of adults with ID (N = 21) received smart speakers, while a control group (N = 22) did not. Before and after about 12 weeks, participants were recorded saying smart speaker-related phrases and unrelated words. Naïve participants then rated the intelligibility of the speech recordings.

OUTCOMES & RESULTS

The group that received smart speakers made significantly larger intelligibility gains than the control group. Although the effect size was modest, this difference was found for both smart speaker-related phrases and unrelated words.

CONCLUSIONS & IMPLICATIONS

While the mechanism of action remains to be determined, the presence of smart speakers in the home had a demonstrable impact on ratings of speech intelligibility, and could provide cost-effective inclusive support for speech and communication improvement, improving the quality of life of vulnerable populations. What this paper adds What is already known on the subject Speech intelligibility is a key obstacle for social relationships and quality of life across several vulnerable populations (children with speech difficulties, older adults with dementia, individuals with ID). Anecdotal reports suggest mainstream smart speakers (e.g., Amazon Alexa, Google Home), could improve speech intelligibility. What this paper adds to existing knowledge We used a semi-randomized controlled trial to show that using a smart speaker for about 12 weeks could improve ratings of speech intelligibility in adults with ID for both smart speaker-related phrases and unrelated words. What are the potential or actual clinical implications of this work? These initial findings suggest that smart speaker technology could be a novel, and inclusive, route to improving speech intelligibility in vulnerable populations.

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.

Is speech and language therapy effective at improving the communication of adults with intellectual disabilities?: A systematic review

BACKGROUND

A significant proportion of adults with intellectual disabilities (ID) experience speech, language and communication difficulties which are associated with poor physical and mental health outcomes. Speech and language therapy (SLT) interventions are an important way to address these communication difficulties, yet there is limited available evidence to provide information about the effectiveness of the different approaches used for this heterogeneous group.

AIMS

To review the evidence available for the effectiveness of SLT interventions aimed at improving communication for adults with ID.

METHODS & PROCEDURES

A systematic search across relevant databases was performed. Information on methodological details of each relevant study, along with descriptions of the SLT interventions employed, were extracted and the Crowe Critical Appraisal Tool (CCAT) was used to assess quality. Findings were discussed in a narrative synthesis grouped by target communication skill.

OUTCOMES & RESULTS

A total of 10 relevant studies met the inclusion criteria. These were predominantly interventions aimed directly at adults with ID to improve speech, increase augmentative and alternative communication (AAC) use and develop interaction skills, with one study addressing work with carers. The included studies were all rated as low quality. There is weak preliminary evidence that SLT input can improve the communication skills of adults with ID.

CONCLUSIONS & IMPLICATIONS

There is insufficient evidence to draw strong conclusions about the effectiveness of SLT in this population. Further high-level evidence across speech, language and communication domains is urgently needed. What this paper adds What is already known on the subject There is limited evidence for community health interventions used with adults with ID. Previous reviews of SLT interventions found a lack of evidence base for this population. Some areas of SLT practice such as AAC have demonstrated potential benefits and other areas including speech work, social communication skills and training for communication partners have some evidence base for children with ID but there is currently insufficient evidence for adults with ID. What this paper adds to existing knowledge The study systematically reviews the current evidence base available when considering the effectiveness of SLT intervention for adults with ID. It provides weak evidence to suggest SLT intervention can improve communication in this population and highlights the need for clinically relevant, robustly designed studies to be undertaken in this field. What are the potential or actual clinical implications of this work? The lack of high-quality studies with sufficient power to draw conclusions about effectiveness means SLTs are not able to base their intervention choices on firm evidence. There is an urgent need to conduct robust research into the effectiveness of SLT interventions for adults with ID.

Behavior skills training for family caregivers of people with intellectual or developmental disabilities: a systematic review of literature

People with intellectual or developmental disabilities (IDDs) face lifelong challenges in areas such as self-care, learning and socializing abilities. Having such individuals at home brings family caregivers extra stress, especially when support is insufficient. Because of the inadequacy of professional support available globally, the need to increase the ability of the caregivers to provide effective support is evident. Behavior skills training (BST), an approach consisting of instruction, modelling, rehearsal, and feedback, has been used in numerous studies to train caregivers in necessary skills to help their family members with IDDs. This study conducted a systematic review of past literatures, wherein BST was used to train family caregivers of individuals with IDDs. Seventeen relevant studies were summarized according to their countries, participant characteristics, training focus, intervention details, and outcomes. Outcomes revealed that BST had been used to train caregivers of varying demographics, various target skills (e.g. discrete trial training, incidental training, etc.), order of delivery, and sometimes the introduction of novel components. Most studies showed an improvement for both caregivers and the individuals with IDDs. However, some studies did not present desired outcomes in relation to the individuals. Possible reasons and future measures were also discussed in this review.

Using Vocal Production to Improve Long-Term Verbal Memory in Adults with Intellectual Disability

Individuals with intellectual disability (ID) typically show weak long-term memory (LTM) skills. Understanding verbal LTM processes and searching for effective mnemonics in this population is important, to improve intervention programs. The current study aimed to assess verbal LTM abilities of adults with mild ID of mixed etiologies, and to offer a simple memorization technique based on vocal production. Participants (n = 55) learned lists of different study materials (images of familiar and unfamiliar objects, written words, and sentences) by vocal production (saying or reading aloud) or by no-production (looking, listening, or reading silently). Memory tests followed. Better memory was found for vocally produced images of familiar objects, written words, and sentences. The results show that adults with mild ID can benefit from the relative distinctiveness of items at study. Hence, vocalization may be used in educational and therapeutic contexts for this population, improving memory performance.

Introducing the Beatalk technique: using beatbox sounds and rhythms to improve speech characteristics of adults with intellectual disability

BACKGROUND

Individuals with intellectual disability (ID) often demonstrate speech impairments and reduced intelligibility. However, traditional treatment methods, which involve using repetitive verbal and non-verbal exercises, may not be fully suitable for this population. As adults with ID tend to lose interest and motivation facing the demands of a typical speech therapy session, other intervention methods are needed. The current study tested a novel intervention technique, Beatalk, based on practising vocally produced sounds and rhythms, imitating the sounds produced by rhythm machines in an a cappella musical context (i.e., human beatboxing). Human beatboxing may be a particularly effective tool since it involves intense production of speech sounds (phonemes) that can be misarticulated in the presence of speech disorders; it is relatively easy to learn and practice, and is also considered 'fun'.

AIMS

As many of the features of beatboxing make it a promising method for speech therapy, this pioneering study aimed to examine its effectiveness in comparison with a traditional speech therapy.

METHODS & PROCEDURES

Twelve adults with moderate ID and low speech intelligibility (age 24-48 years) participated in a speech therapy group for 6 weeks. Six participants were assigned to the Beatalk (study) group and six to a traditional (control) therapy group. Pre- to post-treatment changes in speech intelligibility and voice measures were assessed.

OUTCOMES & RESULTS

The preliminary data demonstrate that both types of therapy groups resulted in improved performance in articulation accuracy and voice measures, yet the Beatalk technique yielded larger gains.

CONCLUSIONS & IMPLICATIONS

The results present initial evidence for the beneficial effect of the Beatalk technique as an intervention tool for adults with ID. It is an easy-to-use technique in the context of speech therapy, and may enhance verbal communication skills in this population.

Use of electropalatography in the treatment of speech disorders in children with Down syndrome: a randomized controlled trial

BACKGROUND

Electropalatography (EPG) records details of the location and timing of tongue contacts with the hard palate during speech. It has been effective in treating articulation disorders that have failed to respond to conventional therapy approaches but, until now, its use with children and adolescents with intellectual/learning disabilities and speech disorders has been limited.

AIMS

To evaluate the usefulness of EPG in the treatment of speech production difficulties in children and adolescents with Down syndrome (DS) aged 8-18 years.

METHODS & PROCEDURES

A total of 27 children with DS were assessed on a range of cognitive and speech and language measures and underwent additional EPG assessment. Participants were randomly allocated to one of three age-matched groups receiving either EPG therapy, EPG-informed conventional therapy or 'treatment as usual' over a 12-week period. The speech of all children was assessed before therapy using the Diagnostic Evaluation of Articulation and Phonology (DEAP) and reassessed immediately post- and 3 and 6 months post-intervention to measure percentage consonants correct (PCC). EPG recordings were made of the DEAP assessment items at all time points. Per cent intelligibility was also calculated using the Children's Speech Intelligibility Measure (CSIM).

OUTCOMES & RESULTS

Gains in accuracy of production immediately post-therapy, as measured by PCC, were seen for all groups. Reassessment at 3 and 6 months post-therapy revealed that those who had received therapy based directly on EPG visual feedback were more likely to maintain and improve on these gains compared with the other groups. Statistical testing showed significant differences between groups in DEAP scores across time points, although the majority did not survive post-hoc evaluation. Intelligibility across time points, as measured by CSIM, was also highly variable within and between the three groups, but despite significant correlations between DEAP and CSIM at all time points, no statistically significant group differences emerged.

CONCLUSIONS & IMPLICATIONS

EPG was an effective intervention tool for improving speech production in many participants. This may be because it capitalizes on the relative strength of visual over auditory processing in this client group. The findings would seem to warrant an increased focus on addressing speech production difficulties in current therapy.

Speech Impairment in Boys With Fetal Alcohol Spectrum Disorders

BACKGROUND

Fetal alcohol spectrum disorders (FASD) are a highly prevalent spectrum of patterns of congenital defects resulting from prenatal exposure to alcohol. Approximately 90% of the cases involve speech impairment. Yet, to date, no detailed symptom profiles nor dedicated treatment plans are available for this population.

PURPOSE

This study set out to chart the speech and speech motor characteristics in boys with FASD to profile the concomitant speech impairment and identify possible underlying mechanisms.

METHOD

Ten boys with FASD (4.5-10.3 years old) and 26 typically developing children (4.1-8.7 years old; 14 boys, 12 girls) participated in the study. Speech production and perception, and oral motor data were collected by standardized tests.

RESULTS

The boys with FASD showed reduced scores on all tasks as well as a deviant pattern of correlations between production and perception tasks and intelligibility compared with the typically developing children. Speech motor profiles showed specific problems with nonword repetition and tongue control.

CONCLUSIONS

Findings indicate that the speech impairment in boys with FASD results from a combination of deficits in multiple subsystems and should be approached as a disorder rather than a developmental delay. The results suggest that reduced speech motor planning/programming, auditory discrimination, and oral motor abilities should be considered in long-term, individually tailored treatment.