Single Word Intelligibility Research Articles

Perceptual measurement of articulatory goodness in young children: Relationships with age, speech sound acquisition, and intelligibility

ABSTRACT Speech language pathologists regularly use perceptual methods in clinical practice to assess children’s speech. In this study, we examined relationships between measures of speech intelligibility, clinical articulation test results, age, and perceptual ratings of articulatory goodness for children. We also examined the extent to which established measures of intelligibility and clinical articulation test results predicted articulatory goodness ratings, and whether goodness ratings were influenced by intelligibility. A sample of 164 (30–47 months) typically developing children provided speech samples and completed a standardised articulation test. Single word intelligibility scores and ratings of articulatory goodness were gathered from 328 naïve listeners; scores on a standardised articulation test were obtained from each child. Bivariate Pearson correlation, linear regression, and linear mixed effects modelling were used for analysis. Results showed that articulatory goodness ratings had the highest correlation with intelligibility, followed by age, followed by articulation score. Age and clinical articulation scores were both significant predictors of goodness ratings, but articulation scores made only a small contribution to prediction. Articulatory goodness ratings were substantially lower for unintelligible words compared to intelligible words, but articulatory goodness scores increased with age at the same rate for unintelligible and intelligible words. Perceptual ratings of articulatory goodness are sensitive to developmental changes in speech production (regardless of intelligibility) and yield a different kind of information than clinical articulation scores from standardised measures.

Efficacy of soft palatal augmentation prosthesis for oral functional rehabilitation in patients with dysarthria and dysphagia: a protocol for a randomised controlled trial

IntroductionPalatal augmentation prosthesis (PAP) is used in patients with articulation and swallowing disorders caused by postoperative loss of tongue tissue due to tongue cancer, cerebrovascular disease sequelae and age-related hypofunction....

Intensive Voice Treatment (Lee Silverman Voice Treatment [LSVT LOUD]) for Children With Down Syndrome: Phase I Outcomes.

This study examined the effects of an intensive voice treatment Lee Silverman Voice Treatment (LSVT LOUD) on children with Down syndrome (DS) and motor speech disorders. A Phase I, multiple baseline, single-subject design with replication across nine participants with DS was used. Single-word intelligibility, acoustic measures of vocal functioning, and parent perceptions of pre- and posttreatment communication function were used as treatment outcome measures. All participants completed the full dose of LSVT LOUD and showed gains on one or more of the outcome measures. Patterns of posttreatment improvements were not consistent across participants but were more frequently observed on trained maximum performance tasks compared to tasks reflecting generalization of the treatment skillset. Some participants exhibited a stronger response to treatment, whereas others showed a mixed or weaker response. Parents liked the treatment protocol, perceived benefits from intensive intervention, and indicated they would strongly recommend LSVT LOUD to other parents who have children with DS and motor speech disorders. These preliminary results show that children with DS tolerated intensive voice treatment without adverse effects and made select meaningful therapeutic gains. The treatment evidence from this study warrants Phase II treatment studies using LSVT LOUD with a larger group of children with DS.

The Relationship Between Single-Word Speech Severity and Intelligibility in Childhood Apraxia of Speech.

The purpose of this study was to investigate the association between perceived single-word speech severity and intelligibility in children with childhood apraxia of speech (CAS), with and without comorbid language impairment (LI), and to investigate the contribution of different CAS signs to perceived single-word speech severity and single-word intelligibility. Thirty children with CAS, 18 with comorbid LI, completed the Goldman-Fristoe Test of Articulation-Second Edition (GFTA-2). Trained judges coded children's responses for signs of CAS and percent phonemes correct. Nine listeners, blind to diagnoses, rated speech severity using a visual analog scale. Intelligibility was assessed by comparing listeners' orthographic transcriptions of children's responses to target responses. Measures of speech severity (GFTA-2 standard score, number of unique CAS signs, total CAS signs, and mean severity rating) were significantly correlated with measures of intelligibility (GFTA-2 raw score, percent phonemes correct, and mean intelligibility score). Speech severity and intelligibility did not differ significantly between children with and without LI. Only consonant errors contributed significant variability to speech severity. Consonant errors and stress errors contributed significant variability to intelligibility. Findings suggest that visual analog scale ratings are a valid and convenient measure of single-word speech severity and that GFTA-2 raw score is an equally convenient measure of single-word intelligibility. The result that consonant errors were by far the major contributor to single-word speech severity and intelligibility in children with CAS, with stress errors also making a small contribution to intelligibility, suggests that consonant accuracy and appropriate lexical stress should be prime therapeutic targets for these children in the context of treatment addressing motor planning/programming, self-monitoring, and self-correcting. https://doi.org/10.23641/asha.19119350.

Speech Development Between 30 and 119 Months in Typical Children I: Intelligibility Growth Curves for Single-Word and Multiword Productions.

PurposeWe extended our earlier study on normative growth curves for intelligibility development in typical children from 30 to 119 months of age. We also determined quantile-specific age of steepest growth and growth rates. A key goal was to establish age-specific benchmarks for single-word and multiword intelligibility.MethodThis cross-sectional study involved collection of in-person speech samples from 538 typically developing children (282 girls and 256 boys) who passed speech, language, and hearing screening measures. One thousand seventy-six normal-hearing naïve adult listeners (280 men and 796 women) orthographically transcribed children's speech. Speech intelligibility was measured as the percentage of words transcribed correctly by naive adults, with single-word and multiword intelligibility outcomes modeled separately.ResultsThe age range for 50% single-word intelligibility was 31–47 months (50th–5th percentiles), the age range for 75% single-word intelligibility was 49–87 months, and the age range for 90% intelligibility for single words was 83–120+ months. The same milestones were attained for multiword intelligibility at 34–46, 46–61, and 62–87 months, respectively. The age of steepest growth for the 50th percentile was 30–31 months for both single-word and multiword intelligibility and was later for children in lower percentiles. The maximum growth rate was 1.7 intelligibility percentage points per month for single words and 2.5 intelligibility percentage points per month for multiword intelligibility.ConclusionsThere was considerable variability in intelligibility development among typical children. For children in median and lower percentiles, intelligibility growth continues through 9 years. Children should be at least 50% intelligible by 48 months.Supplemental Material https://doi.org/10.23641/asha.16583426

Improving speech characteristics of young adults with congenital dysarthria: An exploratory study comparing articulation training and the Beatalk method

IntroductionThis exploratory study compared the effects of two speech therapy approaches on speech characteristics of young adults with congenital dysarthria resulting from various etiologies: a) articulation training focusing on consonant articulation exercises at various levels (isolation, syllables, and words), and b) the Beatalk method, based on human beatboxing, i.e., producing various instrumental sounds in an a-cappella musical context. Both interventions were designed to increase participants’ speech intelligibility. MethodsTwelve adults with congenital dysarthria and reduced speech intelligibility participated in treatment groups for eight weeks. Six participants were assigned to the articulation training group, and six to the Beatalk group. Intelligibility of single words and continuous speech, voice measures, and oral-diadochokinesis rates were measured before and after the treatment. ResultsThe results showed that the Beatalk intervention yielded a significant overall pre- to post-treatment effect. Specifically, it resulted in gains in articulatory accuracy and intelligibility for single words. Improvements were not noted following articulation training. ConclusionsThe results present initial evidence of the positive effect of the Beatalk method as an intervention tool for adults with congenital dysarthria. This relatively easy-to-learn technique shows promise, as it involves intense and repetitive production of speech sounds while controlling rhythm and breathing in an enjoyable context.

Single Word Intelligibility of Individuals with Parkinson's Disease in Noise: Pre-Specified Secondary Outcome Variables from a Randomized Control Trial (RCT) Comparing Two Intensive Speech Treatments (LSVT LOUD vs. LSVT ARTIC).

The majority of people with Parkinson’s disease (PD) experience both prosodic changes (reduced vocal volume, reduced pitch range) and articulatory changes (imprecise articulation) that often limit speech intelligibility and may contribute to significant declines in quality of life. We conducted a randomized control trial comparing two intensive treatments, voice (LSVT LOUD) or articulation (LSVT ARTIC) to assess single word intelligibility in the presence of background noise (babble and mall). Participants (64 PD and 20 Healthy) read words from the diagnostic rhyme test (DRT), an ANSI Standard for measuring intelligibility of speech, before and after one month (treatment or no treatment). Teams of trained listeners blindly rated the data. Speech intelligibility of words in the presence of both noise conditions improved in PD participants who had LSVT LOUD compared to the groups that had LSVT ARTIC or no treatment. Intensive speech treatment targeting prominent prosodic variables in LSVT LOUD had a positive effect on speech intelligibility at the single word level in PD.

Stability of Speech Intelligibility Measures Over Repeated Sampling Times in Speakers With Acquired Apraxia of Speech.

Purpose The purpose of this investigation was to measure the test-retest stability of single-word intelligibility in a group of 28 speakers with chronic apraxia of speech and aphasia. Method The Assessment of Intelligibility of Dysarthric Speech was administered twice to each participant, with samples separated by 1 week. Scoring of recorded samples was completed independently by three expert listeners using transcription and multiple-choice scoring formats. Results Percent intelligible words was very similar for the group over the two sampling times for both scoring formats (i.e., within 1.5%), with no statistically significant differences found between times. Statistically significant, very strong, positive correlations were found between sampling times for intelligibility scores. Transcription and multiple-choice scores were strongly, positively correlated, with multiple-choice scores being statistically higher. There was a statistically significant difference between mean transcription and multiple-choice scores for the group at Time 1 and Time 2. Individual performance was similar to group performance for the majority of participants. Conclusions These findings indicate that single-word intelligibility measures are stable over repeated sampling occasions. Stability was evident for transcription and multiple-choice scoring methods. Supplemental Material https://doi.org/10.23641/asha.14226737.

Audiovisual enhancement and single-word intelligibility in children's speech

It is nearly axiomatic that audiovisual (AV) speech is more intelligible than audio-only (A-only) speech, particularly when the speech is presented in a challenging listening environment, such as in background noise [e.g., MacLeod and Summerfield, Br. J. Audiol., 2 (1987)]. Surprisingly, there has been only limited exploration of differences between individual talkers in the intelligibility advantage of their AV speech over their A-only speech. In this work, we ask whether different age groups of speakers elicit systematically different AV benefits in speech intelligibility tasks. A recent study examined whether children and adults' speech elicits similar AV benefits for sentence intelligibility (Karisny et al., J. Acoust. Soc. Am. 146). In that study, children's speech elicited smaller AV benefits than adults' speech, though this comparison was complicated by suboptimal choice of different signal-to-noise ratios to equate the groups' intelligibility in A-only conditions. The current study follows up on this work by examining single-word intelligibility in the same talkers, using a single SNR for both groups. Data collection is ongoing. Results will help us understand the role of individual-speaker variation on the magnitude of AV benefit.

Development of Speech Intelligibility Between 30 and 47 Months in Typically Developing Children: A Cross-Sectional Study of Growth.

Purpose We sought to establish normative growth curves for intelligibility development for the speech of typically developing children as revealed by objectively based orthographic transcription of elicited single-word and multiword utterances by naïve listeners. We also examined sex differences, and we compared differences between single-word and multiword intelligibility growth. Method One hundred sixty-four typically developing children (92 girls, 72 boys) contributed speech samples for this study. Children were between the ages of 30 and 47 months, and analyses examined 1-month age increments between these ages. Two different naïve listeners heard each child and made orthographic transcriptions of child-produced words and sentences (n = 328 listeners). Average intelligibility scores for single-word productions and multiword productions were modeled using linear regression, which estimated normal-model quantile age trajectories for single- and multiword utterances. Results We present growth curves showing steady linear change over time in 1-month increments from 30 to 47 months for 5th, 10th, 25th, 50th, 75th, 90th, and 95th percentiles. Results showed that boys did not differ from girls and that, prior to 35 months of age, single words were more intelligible than multiword productions. Starting at 41 months of age, the reverse was true. Multiword intelligibility grew at a faster rate than single-word intelligibility. Conclusions Children make steady progress in intelligibility development through 47 months, and only a small number of children approach 100% intelligibility by this age. Intelligibility continues to develop past the fourth year of life. There is considerable variability among children with regard to intelligibility development. Supplemental Material https://doi.org/10.23641/asha.12330956.

Longitudinal Growth in Single-Word Intelligibility Among Children With Cerebral Palsy From 24 to 96 Months of Age: Effects of Speech-Language Profile Group Membership on Outcomes.

Purpose We examined whether there were differences among speech-language profile groups of children with cerebral palsy (CP) in age of crossing 25%, 50%, and 75% intelligibility thresholds; age of greatest intelligibility growth; rate of intelligibility growth; maximum attained intelligibility at 8 years; and how well intelligibility at 36 months predicts intelligibility at 96 months when group membership is accounted for. Profile groups were children with no speech motor impairment (NSMI), those with speech motor impairment and language comprehension that is typically developing (SMI-LCT), and those with speech motor impairment and language comprehension impairment (SMI-LCI). Method Sixty-eight children with CP were followed longitudinally between 24 and 96 months of age. A total of 564 time points were examined across children (M = 8.3 time points per child, SD = 2.6). We fitted a nonlinear random effects model for longitudinal observations, allowing for differences between profile groups. We used the fitted model trajectories to generate descriptive analyses of intelligibility growth by group and to generate simulations to analyze how well 36-month intelligibility data predicted 96-month data accounting for profile groups. Results Children with CP who have NSMI have different growth and better intelligibility outcomes than those with speech motor impairment. Children with SMI-LCT tend to have better outcomes but similar intelligibility growth as children with SMI-LCI. There may be a subset of children that cut across SMI-LCI and SMI-LCT groups who have severe speech motor involvement and show limited growth in intelligibility. Conclusions Intelligibility outcomes for children with CP are affected by profile group membership. Intelligibility growth tends to be delayed in children with speech motor impairment. Intelligibility at 3 years is highly predictive of later outcomes regardless of profile group. Intervention decision making should include consideration of early intelligibility, and treatment directions should include consideration of augmentative and alternative communication.

Beavertail modification of the radial forearm free flap in total oral glossectomy reconstruction: Technique and functional outcomes

ObjectiveThe total oral tongue (anterior 2/3 glossectomy) defect is seldom addressed in the literature. This is the first series to describe a consistent technique for its reconstruction. The aim of the study is to describe the use of the beavertail modified radial forearm free flap (BTRFFF) to reconstruct a total oral tongue defect and the functional and quality of life outcomes associated with it. Study designRetrospective review of prospectively collected data from 2000 to 2010. MethodsAll patients at the University of Alberta undergoing head and neck free flap surgery are enrolled in a prospective functional outcomes program. Pre-operatively and at set post-operative time points patients complete videofluoroscopic swallowing studies (VFSS), speech evaluations and quality of life questionnaires (EORTC H&N-35). Peri-operative outcomes were also measured. Results17 consecutive patients were included. All were gastrostomy tube free at 12 months post-operatively and tolerating a full soft diet with aspiration scores of 0. Swallowing transit times increased by a mean of 0.4 s (p = 0.32). Speech intelligibility remained high with mean sentence intelligibility at 75% and single word intelligibility at 62%. Quality of life scores returned to baseline and remained satisfactory. Complications related to the BTRFFF were limited to scarring. ConclusionsThe BTRFFF provides a robust reconstructive option for the total oral tongue defect with excellent long term functional outcomes and quality of life.

Construct Validity of the Viking Speech Scale

Objective: The Viking Speech Scale (VSS) reliably classifies the speech performance of children with cerebral palsy. This paper aims to establish the construct validity of the VSS by testing the extent to which percentage intelligibility in single word speech and connected speech predicts VSS rating. Patients and Methods: This is a secondary analysis of two sets of anonymised data collected for previous research. The full data set comprised 79 children with cerebral palsy from the US (n = 43) and the UK (n = 36): (43 boys, 36 girls); mean age 7.2 years (SD 3.3). Single word intelligibility was measured using the TOCS+ words for US children and Children’s Speech Intelligibility Measure for the UK children. Connected speech intelligibility was measured from a subset of repeated sentences in TOCS+ for US children and picture description for the UK children. We used ordinal logistic regression to examine prediction of VSS rating by percentage single word and connected speech intelligibility scores in both samples. Results: Percentage single word intelligibility and connected speech intelligibility predicted VSS rating in univariate and multivariate regression models for both the US and UK samples. Conclusion: Intelligibility predicts VSS for both single words and connected speech, establishing the construct validity of VSS.

Longitudinal Growth in Single Word Intelligibility Among Children With Cerebral Palsy From 24 to 96 Months of Age: Predicting Later Outcomes From Early Speech Production.

Purpose Children with cerebral palsy (CP) are at risk for significant communication problems. Reduced speech intelligibility is common, even for those who do not have speech motor deficits. Development of intelligibility has not been comprehensively quantified in children with CP; as a result, we are currently unable to predict later speech outcomes. Such information would advance treatment decision making. We sought to examine growth in speech intelligibility among children with CP using a prospective longitudinal design, with a focus on age of crossing target intelligibility thresholds, age of greatest intelligibility growth, and how well intelligibility at 36 months predicted intelligibility at 96 months. Method Sixty-nine children with CP were followed longitudinally between 24 and 96 months of age. A total of 566 time points were examined across children ( M = 8.2 time points per child, SD = 2.6). We fitted a nonlinear random effects model for longitudinal observations and then used the fitted model trajectories to generate descriptive analyses of growth. We used results of the model to generate a set of simulations, which we analyzed to determine how well 36-month intelligibility data predicted 96-month data. Results Half of children crossed 25% and 50% intelligibility thresholds at 36 and 49 months of age, respectively. Slightly more than half of children did not reach 75% intelligibility by 96 months of age. Age of crossing 25%, 50%, and 75% intelligibility thresholds was highly negatively correlated with intelligibly at 96 months. Children had the steepest intelligibility growth at 36 months, followed by 48 and 60 months. Intelligibility at 36 months was highly predictive of intelligibility at 96 months. Conclusions The developmental window from 3 to 5 years constitutes a time of rapid growth in speech intelligibility in children with CP. Children who cross intelligibility thresholds of 25%, 50%, and 75% at earlier ages have better outcomes when they are older; early performance is highly predictive of later speech intelligibility outcomes. Children with CP as a group have delayed speech intelligibility development but are still growing through 96 months of age.

Semantic predictability and the use of creaky voice in female speakers

The purpose of this study was to investigate the prevalence of creaky voice in sentence-final position as a function of semantic predictability of the final word. Creaky voice is maligned in the media and often claimed to be less intelligible than normal phonation. A recent study finds some evidence to support this claim by examining intelligibility of single words. If speakers were concerned about intelligibility of their speech, they may be less likely to use it in sentences with little semantic support (e.g., “Mr. Black knew about the pad” compared to “Tear off some paper from the pad”). In the current study, 11 young female speakers without any vocal pathologies produced sentences from the Speech Perception in Noise (SPIN) test. Fourteen final words that appeared in both high and low semantic predictability sentences were selected for analysis. Three outcome measures were examined for these final words: presence versus absence of creaky voice, duration of creaky voice, and type of creaky voice. Contrary to our expectations, the results indicated that semantic support does not significantly predict the existence, amount, or type of creaky voice in young female speakers.

Longitudinal development of communication in children with cerebral palsy between 24 and 53 months: Predicting speech outcomes

ABSTRACTObjective: To determine whether communication at 2 years predicted communication at 4 years in children with cerebral palsy (CP); and whether the age a child first produces words imitatively predicts change in speech production. Method: 30 children (15 males) with CP participated and were seen 5 times at 6-month intervals between 24 and 53 months (mean age at time 1 = 26.9 months (SD 1.9)). Variables were communication classification at 24 and 53 months, age that children were first able to produce words imitatively, single-word intelligibility, and longest utterance produced. Results: Communication at 24 months was highly predictive of abilities at 53 months. Speaking earlier led to faster gains in intelligibility and length of utterance and better outcomes at 53 months than speaking later. Conclusion: Inability to speak at 24 months indicates greater speech and language difficulty at 53 months and a strong need for early communication intervention.

Therapeutic effects of intensive voice treatment (LSVT LOUD®) for children with spastic cerebral palsy and dysarthria: A phase I treatment validation study

Purpose: The aim of the present study was to validate and extend the evaluation of treatment outcomes following LSVT LOUD® in children with dysarthria secondary to cerebral palsy (CP).Method: Seven children (5 females, 6–10 years) with spastic quadriplegia and dysarthria received LSVT LOUD. Outcomes included: (a) quantitative and qualitative indices of communication and social functioning representing therapeutic effects and (b) features of the acoustic signal representing physiological effects on the speech mechanism. A matched group of typically developing children served as controls. Testing occurred just prior to (PRE), immediately following (POST), and at 12 weeks post-treatment (FUP).Result: Expert listeners preferred voice quality and articulatory precision of children with CP at FUP as compared to PRE. Acoustic data indicated improvements on select measures of vocal functioning at POST with some maintenance at FUP. Single word intelligibility improved immediately POST, but was not maintained at FUP. Parents rated positive changes in characteristics of voice and speech and qualitative changes in communication at both POST and FUP.Conclusion: The present study validated some of the previous LSVT LOUD outcomes in children with dysarthria and CP and extended our understanding of therapeutic effects through qualitative data obtained from extensive parent interviews.

Protocol for the Evaluation of Speech Intelligibility in Dysarthrias: Evidence of Reliability and Validity

Background/Aims: Studies about the reliability and validity of intelligibility measures are fundamental to direct their use and interpretation in both clinical and research settings. The present study assessed inter-rater reliability, internal consistency and criterion validity of scores for the sentence and word subtests of the Protocol for the Evaluation of Speech Intelligibility (PESI). Methods: This study included 180 adult volunteers who were divided into three groups: 30 speakers with dysarthria, 30 control speakers and 120 listeners. Intelligibility scores were calculated according to the percentage of words correctly transcribed in each subtest: words in sentences and single words. Results: The intelligibility measurements exhibited a high level of inter-rater reliability for sentences [intraclass correlation coefficient (ICC) = 0.94] and for single words (ICC = 0.96). The items from the single words subtest of the PESI revealed high internal consistency (Cronbach's alpha = 0.93). The measurement of intelligibility of sentences and single words had a high discriminatory power (0.82 and 0.95, respectively), with high sensitivity and specificity, particularly for scores in the single words subtest. Conclusion: This study provides preliminary evidence of the reliability and validity of the PESI.

Swedish Test of Intelligibility for Children (STI-CH) – Validity and reliability of a computer-mediated single word intelligibility test for children

The aim of this study was twofold: first, to describe a new Swedish intelligibility test (Swedish Test of Intelligibility for Children, STI-CH) and second to evaluate its validity and reliability. STI-CH is based on the repetition of single words. Ten children with a speech-sound disorder (4:6–8:3 years of age, mean = 6.0 years) and 10 children with typical speech and language development (4:8–7:4 years of age, mean = 5.9 years) were included. Twenty speech-language pathology students served as listeners. Intra-judge reliability was high (r > 0.92), as was the intra-class correlation of inter-judge reliability (0.97). In terms of validity, there was a significant difference in STI-CH scores between the two groups, and the scores correlated statistically significantly with the Percentage of Consonants Correct (r = 0.94) and with intelligibility in spontaneous speech (r = 0.85). To sum up, the results indicate that STI-CH could be an option for the assessment of intelligibility in Swedish-speaking children, and that the principles used in the development of the test could be of use in the design of intelligibility tests in languages other than Swedish.

Single-word intelligibility testing in aphasia: Alternate forms reliability, phonetic complexity and word frequency

Background: We recently constructed a single-word speech intelligibility test intended to quantify magnitude of speech sound impairment in individuals with aphasia. To minimise listener learning and strategising, the test included a large set of possible (alternate) test forms and was constructed with high and diverse phonologic similarity among candidate words. Although the corpus was limited in phonetic complexity to single syllables, and although criteria for minimal word frequency were applied, it is possible that more fine-grained differences in phonetic complexity and/or word frequency may introduce varying levels of difficulty across alternate test forms and that reliability, therefore, may be compromised.Aims: The dual purposes of this study were to evaluate alternate forms reliability for the new intelligibility test and to determine whether word frequency and/or phonetic complexity affected word identification scores.Methods & Procedures: All words in the 600-word test corpus were coded for overall phonetic complexity and for frequency of occurrence in spoken English. Fifty-one versions of the target 50-word test were generated from this corpus by following designated pseudo-random selection procedures. Speech samples were collected from 13 speakers with aphasia, who each repeated three or four of these 50-word sets. Ten normal-hearing listeners were asked to indicate the words they thought the speakers were trying to say. Per cent accuracy was computed for each speaker, test form and target word.Outcomes & Results: The intra-class correlation within speakers was 0.97, indicating that the scores across alternate forms were highly reproducible. Analyses at the word level showed that both phonetic complexity and word frequency affected identification accuracy. The effects were seen in almost all participants whose intelligibility scores were in the impaired range.Conclusions: High frequency of occurrence and low phonetic complexity increase repetition accuracy for individuals with moderate to severe sound production difficulties and aphasia. However, the pseudo-random word selection in the examined word intelligibility test was sufficient to ensure strong alternate forms reliability. Further constraints on the word selection process for this test are not warranted.