The association between longitudinal declines in speech sound accuracy and speech intelligibility in speakers with amyotrophic lateral sclerosis.

The purpose of this study was to examine how neurodegeneration secondary to amyotrophic lateral sclerosis (ALS) impacts speech sound accuracy over time and how speech sound accuracy, in turn, is related to speech intelligibility. Twenty-one participants with ALS read the Bamboo Passage over multiple data collection sessions across several months. Phonemic and orthographic transcriptions were completed for all speech samples. The percentage of phonemes accurately produced was calculated across each phoneme, sound class (i.e. consonants versus vowels), and distinctive feature (i.e. features involved in Manner of Articulation, Place of Articulation, Laryngeal Voicing, Tongue Height, and Tongue Advancement). Intelligibility was determined by calculating the percentage of words correctly transcribed orthographically by naive listeners. Linear mixed effects models were conducted to assess the decline of each distinctive feature over time and its impact on intelligibility. The results demonstrated that overall phonemic production accuracy had a nonlinear relationship with speech intelligibility and that a subset of features (i.e. those dependent on precise lingual and labial constriction and/or extensive lingual and labial movement) were more important for intelligibility and were more impacted over time than other features. Furthermore, findings revealed that consonants were more strongly associated with intelligibility than vowels, but consonants did not significantly differ from vowels in their decline over time. These findings have the potential to (1) strengthen mechanistic understanding of the physiological constraints imposed by neuronal degeneration on speech production and (2) inform the timing and selection of treatment and assessment targets for individuals with ALS.

Two Distinct Clinical Phenotypes of Bulbar Motor Impairment in Amyotrophic Lateral Sclerosis.

Objective: Understanding clinical variants of motor neuron diseases such as amyotrophic lateral sclerosis (ALS) is critical for discovering disease mechanisms and across-patient differences in therapeutic response. The current work describes two clinical subgroups of patients with ALS that, despite similar levels of bulbar motor involvement, have disparate clinical and functional speech presentations. Methods: Participants included 47 healthy control speakers and 126 speakers with ALS. Participants with ALS were stratified into three clinical subgroups (i.e., bulbar asymptomatic, bulbar symptomatic high speech function, and bulbar symptomatic low speech function) based on clinical metrics of bulbar motor impairment. Acoustic and lip kinematic analytics were derived from each participant's recordings of reading samples and a rapid syllable repetition task. Group differences were reported on clinical scales of ALS and bulbar motor severity and on multiple speech measures. Results: The high and low speech-function subgroups were found to be similar on many of the dependent measures explored. However, these two groups were differentiated on the basis of an acoustic measure used as a proxy for tongue movement. Conclusion: This study supports the hypothesis that high and low speech-function subgroups do not differ solely in overall severity, but rather, constitute two distinct bulbar motor phenotypes. The findings suggest that the low speech-function group exhibited more global involvement of the bulbar muscles than the high speech-function group that had relatively intact lingual function. This work has implications for clinical measures used to grade bulbar motor involvement, suggesting that a single bulbar measure is inadequate for capturing differences among phenotypes.

Initial studies of the phenotype and persistence of speech motor delay (SMD).

Speech Motor Delay (SMD) is a recently proposed childhood motor speech disorder characterized by imprecise and unstable speech, prosody, and voice that does not meet criteria for either Childhood Dysarthria or Childhood Apraxia of Speech. The goals of the present research were to obtain information on the phenotype of SMD and initial information on the persistence of SMD in children receiving treatment for idiopathic Speech Delay (SD). Five questions about the phenotype and persistence of SMD were posed using a database of audio-recordings and participant records and longitudinal data from audio-recordings of children with early SMD treated for SD. Three phenotype questions examined associations between participant risk factors and prevalence of SMD, and described the most frequent speech, prosody, and voice signs of early SMD. To provide initial estimates of the persistence of SMD, two questions examined associations between the persistence of SMD and participant risk factors using the audio-recordings of 14 participants with SMD treated for idiopathic SD. Phenotype findings indicated that SMD is characterized by across-the-board delays in the spatiotemporal precision and stability of speech, prosody, and voice production. Persistence findings indicated that although most participants normalized early SMD by 6 years of age, SMD persisted until at least late adolescence in 21.4% of participants. Findings are interpreted to support the construct validity of SMD and the potential for research using additional assessment modalities to explicate its genomic and neuromotor causal pathways. Abbreviations: CAS: Childhood Apraxia of Speech; CD: Childhood Dysarthria; MSD: Motor Speech Disorder; No MSD: No Motor Speech Disorder; PSI: Precision-Stability Index; SD: Speech Delay; SMD: Speech Motor Delay; SSD: Speech Sound Disorders.

Automatic Screening to Detect 'At Risk' Child Speech Samples using a Clinical Group Verification framework.

Pediatric speech sound disorders (SSD) encompass a wide range of speech production deficits that can interfere with children's educational growth, social engagement and employment opportunities. Early detection of SSDs can facilitate timely intervention and minimize the potential for life-long adverse effects, but distinguishing between typical and atypical speech production in preschoolers is challenging due to developmental and individual variability in speech acquisition. In this study we apply Gaussian Mixture Models to speech samples from 3- to 6-year-old children, recorded by parents using an iOS app. Speech-language pathologists previously classified the samples as positive ('at risk' speech, warranting a referral for a speech-language evaluation) or negative ('no risk' speech). In a series of exploratory analyses, novel distance measures and group scoring techniques are developed which show good subject-level prediction accuracy. Our results provide evidence that it may be feasible to use Speech Processing and Speaker Verification techniques to model and screen speech samples from children for possible speech sound disorders.

Automatic prediction of intelligible speaking rate for individuals with ALS from speech acoustic and articulatory samples.

Purpose: This research aimed to automatically predict intelligible speaking rate for individuals with Amyotrophic Lateral Sclerosis (ALS) based on speech acoustic and articulatory samples. Method: Twelve participants with ALS and two normal subjects produced a total of 1831 phrases. NDI Wave system was used to collect tongue and lip movement and acoustic data synchronously. A machine learning algorithm (i.e. support vector machine) was used to predict intelligible speaking rate (speech intelligibility × speaking rate) from acoustic and articulatory features of the recorded samples. Result: Acoustic, lip movement, and tongue movement information separately, yielded a R2 of 0.652, 0.660, and 0.678 and a Root Mean Squared Error (RMSE) of 41.096, 41.166, and 39.855 words per minute (WPM) between the predicted and actual values, respectively. Combining acoustic, lip and tongue information we obtained the highest R2 (0.712) and the lowest RMSE (37.562 WPM). Conclusion: The results revealed that our proposed analyses predicted the intelligible speaking rate of the participant with reasonably high accuracy by extracting the acoustic and/or articulatory features from one short speech sample. With further development, the analyses may be well-suited for clinical applications that require automatic speech severity prediction.

Kinematic Features of Jaw and Lips Distinguish Symptomatic From Presymptomatic Stages of Bulbar Decline in Amyotrophic Lateral Sclerosis.

Purpose: The goals of this study were to (a) classify speech movements of patients with amyotrophic lateral sclerosis (ALS) in presymptomatic and symptomatic phases of bulbar function decline relying solely on kinematic features of lips and jaw and (b) identify the most important measures that detect the transition between early and late bulbar changes. Method: One hundred ninety-two recordings obtained from 64 patients with ALS were considered for the analysis. Feature selection and classification algorithms were used to analyze lip and jaw movements recorded with Optotrak Certus (Northern Digital Inc.) during a sentence task. A feature set, which included 35 measures of movement range, velocity, acceleration, jerk, and area measures of lips and jaw, was used to classify sessions according to the speaking rate into presymptomatic (> 160 words per minute) and symptomatic (< 160 words per minute) groups. Results: Presymptomatic and symptomatic phases of bulbar decline were distinguished with high accuracy (87%), relying only on lip and jaw movements. The best features that allowed detecting the differences between early and later bulbar stages included cumulative path of lower lip and jaw, peak values of velocity, acceleration, and jerk of lower lip and jaw. Conclusion: The results established a relationship between facial kinematics and bulbar function decline in ALS. Considering that facial movements can be recorded by means of novel inexpensive and easy-to-use, video-based methods, this work supports the development of an automatic system for facial movement analysis to help clinicians in tracking the disease progression in ALS.

Cutting-Edge Technology for Speech Rehabilitation.

Purpose: The authors of this article introduce the technical reports of this special issue.

The diagnostic utility of patient-report and speech-language pathologists' ratings for detecting the early onset of bulbar symptoms due to ALS.

OBJECTIVE: This study aimed to determine the diagnostic utility of clinician speech ratings and patient self-report for detecting early bulbar changes associated with amyotrophic lateral sclerosis (ALS), compared to instrumentation-based speech measures. METHODS: Thirty-six individuals with ALS and 17 healthy control participants were included. Patients' awareness of early bulbar motor involvement was assessed using self-reported scores on the Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised (ALSFRS-R). Clinicians' detection of early bulbar motor involvement was assessed through perceptual speech ratings by two experienced speech-language pathologists. Participants with ALS were grouped as 'bulbar pre-symptomatic' or 'bulbar symptomatic' based on self-report and clinician ratings, and compared to healthy controls on six instrumentation-based speech measures. ROC analysis was used to compare the sensitivity and specificity of perceptual and instrumentation-based measures for detecting bulbar changes in pre-symptomatic individuals. RESULTS: Early bulbar changes that were documented using instrumentation-based measures were undetected by both patients and clinicians. ROC analyses indicated that instrumentation-based measures outperformed clinicians' scaled severity ratings, and that percent pause time was the best measure for differentiating healthy controls from bulbar pre-symptomatic individuals with ALS. CONCLUSIONS: Findings suggested that instrumentation-based measures of speech may be necessary for early detection of bulbar changes due to ALS.

Predicting Intelligible Speaking Rate in Individuals with Amyotrophic Lateral Sclerosis from a Small Number of Speech Acoustic and Articulatory Samples.

Amyotrophic lateral sclerosis (ALS) is a rapidly progressive neurological disease that affects the speech motor functions, resulting in dysarthria, a motor speech disorder. Speech and articulation deterioration is an indicator of the disease progression of ALS; timely monitoring of the disease progression is critical for clinical management of these patients. This paper investigated machine prediction of intelligible speaking rate of nine individuals with ALS based on a small number of speech acoustic and articulatory samples. Two feature selection techniques - decision tree and gradient boosting - were used with support vector regression for predicting the intelligible speaking rate. Experimental results demonstrated the feasibility of predicting intelligible speaking rate from only a small number of speech samples. Furthermore, adding articulatory features to acoustic features improved prediction performance, when decision tree was used as the feature selection technique.

Data-driven subclassification of speech sound disorders in preschool children.

PURPOSE: The purpose of the study was to determine whether distinct subgroups of preschool children with speech sound disorders (SSD) could be identified using a subgroup discovery algorithm (SUBgroup discovery via Alternate Random Processes, or SUBARP). Of specific interest was finding evidence of a subgroup of SSD exhibiting performance consistent with atypical speech motor control. METHOD: Ninety-seven preschool children with SSD completed speech and nonspeech tasks. Fifty-three kinematic, acoustic, and behavioral measures from these tasks were input to SUBARP. RESULTS: Two distinct subgroups were identified from the larger sample. The 1st subgroup (76%; population prevalence estimate = 67.8%-84.8%) did not have characteristics that would suggest atypical speech motor control. The 2nd subgroup (10.3%; population prevalence estimate = 4.3%-16.5%) exhibited significantly higher variability in measures of articulatory kinematics and poor ability to imitate iambic lexical stress, suggesting atypical speech motor control. Both subgroups were consistent with classes of SSD in the Speech Disorders Classification System (SDCS; Shriberg et al., 2010a). CONCLUSION: Characteristics of children in the larger subgroup were consistent with the proportionally large SDCS class termed speech delay; characteristics of children in the smaller subgroup were consistent with the SDCS subtype termed motor speech disorder-not otherwise specified. The authors identified candidate measures to identify children in each of these groups.

Physics-based deformable tongue visualization.

In this paper, a physics-based framework is presented to visualize the human tongue deformation. The tongue is modeled with the Finite Element Method (FEM) and driven by the motion capture data gathered during speech production. Several novel deformation visualization techniques are presented for in-depth data analysis and exploration. To reveal the hidden semantic information of the tongue deformation, we present a novel physics-based volume segmentation algorithm. This is accomplished by decomposing the tongue model into segments based on its deformation pattern with the computation of deformation subspaces and fitting the target deformation locally at each segment. In addition, the strain energy is utilized to provide an intuitive low-dimensional visualization for the high-dimensional sequential motion. Energy-interpolation-based morphing is also equipped to effectively highlight the subtle differences of the 3D deformed shapes without any visual occlusion. Our experimental results and analysis demonstrate the effectiveness of this framework. The proposed methods, though originally designed for the exploration of the tongue deformation, are also valid for general deformation analysis of other shapes.

Consonant accuracy after severe pediatric traumatic brain injury: a prospective cohort study.

PURPOSE: The authors sought to describe longitudinal changes in Percentage of Consonants Correct-Revised (PCC-R) after severe pediatric traumatic brain injury (TBI), to compare the odds of normal-range PCC-R in children injured at older and younger ages, and to correlate predictor variables and PCC-R outcomes. METHOD: In 56 children injured between age 1 month and 11 years, PCC-R was calculated over 12 monthly sessions beginning when the child produced ≥ 10 words. At each session, the authors compared odds of normal-range PCC-R in children injured at younger (≤ 60 months) and older (> 60 months) ages. Correlations were calculated between final PCC-R and age at injury, injury mechanism, gender, maternal education, residence, treatment, Glasgow Coma Score, and intact brain volume. RESULTS: PCC-Rs varied within and between children. Odds of normal-range PCC-R were significantly higher for the older than for the younger group at all sessions but the first; odds of normal-range PCC-R were 9 to 33 times higher in the older group in sessions 3 to 12. Age at injury was significantly correlated with final PCC-R. CONCLUSION: Over a 12-month period, severe TBI had more adverse effects for children whose ages placed them in the most intensive phase of PCC-R development than for children injured later.

Distinct developmental profiles in typical speech acquisition.

Three- to five-year-old children produce speech that is characterized by a high level of variability within and across individuals. This variability, which is manifest in speech movements, acoustics, and overt behaviors, can be input to subgroup discovery methods to identify cohesive subgroups of speakers or to reveal distinct developmental pathways or profiles. This investigation characterized three distinct groups of typically developing children and provided normative benchmarks for speech development. These speech development profiles, identified among 63 typically developing preschool-aged speakers (ages 36-59 mo), were derived from the children's performance on multiple measures. These profiles were obtained by submitting to a k-means cluster analysis of 72 measures that composed three levels of speech analysis: behavioral (e.g., task accuracy, percentage of consonants correct), acoustic (e.g., syllable duration, syllable stress), and kinematic (e.g., variability of movements of the upper lip, lower lip, and jaw). Two of the discovered group profiles were distinguished by measures of variability but not by phonemic accuracy; the third group of children was characterized by their relatively low phonemic accuracy but not by an increase in measures of variability. Analyses revealed that of the original 72 measures, 8 key measures were sufficient to best distinguish the 3 profile groups.

Recommendations for the use of common outcome measures in pediatric traumatic brain injury research.

This article addresses the need for age-relevant outcome measures for traumatic brain injury (TBI) research and summarizes the recommendations by the inter-agency Pediatric TBI Outcomes Workgroup. The Pediatric Workgroup's recommendations address primary clinical research objectives including characterizing course of recovery from TBI, prediction of later outcome, measurement of treatment effects, and comparison of outcomes across studies. Consistent with other Common Data Elements (CDE) Workgroups, the Pediatric TBI Outcomes Workgroup adopted the standard three-tier system in its selection of measures. In the first tier, core measures included valid, robust, and widely applicable outcome measures with proven utility in pediatric TBI from each identified domain including academics, adaptive and daily living skills, family and environment, global outcome, health-related quality of life, infant and toddler measures, language and communication, neuropsychological impairment, physical functioning, psychiatric and psychological functioning, recovery of consciousness, social role participation and social competence, social cognition, and TBI-related symptoms. In the second tier, supplemental measures were recommended for consideration in TBI research focusing on specific topics or populations. In the third tier, emerging measures included important instruments currently under development, in the process of validation, or nearing the point of published findings that have significant potential to be superior to measures in the core and supplemental lists and may eventually replace them as evidence for their utility emerges.

A nonword repetition task for speakers with misarticulations: the Syllable Repetition Task (SRT).

PURPOSE: Conceptual and methodological confounds occur when non(sense) word repetition tasks are administered to speakers who do not have the target speech sounds in their phonetic inventories or who habitually misarticulate targeted speech sounds. In this article, the authors (a) describe a nonword repetition task, the Syllable Repetiton Task (SRT), that eliminates this confound and (b) report findings from 3 validity studies. METHOD: Ninety-five preschool children with speech delay and 63 with typical speech completed an assessment battery that included the Nonword Repetition Task (NRT; C. Dollaghan & T. F. Campbell, 1998) and the SRT. SRT stimuli include only 4 of the earliest occurring consonants and 1 early occurring vowel. RESULTS: Study 1 findings indicated that the SRT eliminated the speech confound in nonword testing with speakers who misarticulate. Study 2 findings indicated that the accuracy of the SRT to identify expressive language impairment was comparable to findings for the NRT. Study 3 findings illustrated the SRT's potential to interrogate speech processing constraints underlying poor nonword repetition accuracy. Results supported both memorial and auditory-perceptual encoding constraints underlying nonword repetition errors in children with speech-language impairment. CONCLUSION: The SRT appears to be a psychometrically stable and substantively informative nonword repetition task for emerging genetic research and other research with speakers who misarticulate.

A performance curve for assessing change in Percentage of Consonants Correct Revised (PCC-R).

PURPOSE: Interpreting the rapidly changing speech skills of young children recovering from neurological injury is difficult because developmental expectations are generally available only at relatively lengthy intervals (e.g., 6 or 12 months). In this research note, the authors describe the process of generating a Percentage of Consonants Correct-Revised (PCC-R; L. D. Shriberg, D. Austin, B. A. Lewis, J. L. McSweeny, & D. L. Wilson, 1997a) performance curve and illustrate some of its applications for assessing change in performance over time. METHOD: The authors compiled mean PCC-R scores from 16 samples of typically developing children (18-172 months) and used curve fitting to test more than 11,000 statistical models of monthly growth in PCC-R. They selected a parsimonious and developmentally plausible model with R(2) = .9839 (p < .0005) and used it to generate the PCC-R, standard deviation, and standard error expected at each monthly age. RESULTS: The PCC-R performance curve distinguished among 65 children (37-57 months of age) diagnosed independently with normal or disordered speech with a high degree of success. More important, the PCC-R performance curve can be used to identify the points at which children (18-172 months) recovering from neurological injury achieve normal-range consonant production. CONCLUSION: The curve-fitting approach holds promise as a means of interpreting temporal variations in speech production at a finer grain than existing normative data currently allow.

Tympanostomy tubes and developmental outcomes at 9 to 11 years of age.

BACKGROUND: Developmental impairments in children have been attributed to persistent middle-ear effusion in their early years of life. Previously, we reported that among children younger than 3 years of age with persistent middle-ear effusion, prompt as compared with delayed insertion of tympanostomy tubes did not result in improved cognitive, language, speech, or psychosocial development at 3, 4, or 6 years of age. However, other important components of development could not be assessed until the children were older. METHODS: We enrolled 6350 infants soon after birth and evaluated them regularly for middle-ear effusion. Before 3 years of age, 429 children with persistent effusion were randomly assigned to undergo the insertion of tympanostomy tubes either promptly or up to 9 months later if effusion persisted. We assessed literacy, attention, social skills, and academic achievement in 391 of these children at 9 to 11 years of age. RESULTS: Mean (+/-SD) scores on 48 developmental measures in the group of children who were assigned to undergo early insertion of tympanostomy tubes did not differ significantly from the scores in the group that was assigned to undergo delayed insertion. These measures included the Passage Comprehension subtest of the Woodcock Reading Mastery Tests (mean score, 98+/-12 in the early-treatment group and 99+/-12 in the delayed-treatment group); the Spelling, Writing Samples, and Calculation subtests of the Woodcock-Johnson III Tests of Achievement (96+/-13 and 97+/-16; 104+/-14 and 105+/-15; and 99+/-13 and 99+/-13, respectively); and inattention ratings on visual and auditory continuous performance tests. CONCLUSIONS: In otherwise healthy young children who have persistent middle-ear effusion, as defined in our study, prompt insertion of tympanostomy tubes does not improve developmental outcomes up to 9 to 11 years of age. (ClinicalTrials.gov number, NCT00365092 [ClinicalTrials.gov].).

Developmental outcomes after early or delayed insertion of tympanostomy tubes.

BACKGROUND: To prevent later developmental impairments, myringotomy with the insertion of tympanostomy tubes has often been undertaken in young children who have persistent otitis media with effusion. We previously reported that prompt as compared with delayed insertion of tympanostomy tubes in children with persistent effusion who were younger than three years of age did not result in improved developmental outcomes at three or four years of age. However, the effect on the outcomes of school-age children is unknown. METHODS: We enrolled 6350 healthy infants younger than 62 days of age and evaluated them regularly for middle-ear effusion. Before three years of age, 429 children with persistent middle-ear effusion were randomly assigned to have tympanostomy tubes inserted either promptly or up to nine months later if effusion persisted. We assessed developmental outcomes in 395 of these children at six years of age. RESULTS: At six years of age, 85 percent of children in the early-treatment group and 41 percent in the delayed-treatment group had received tympanostomy tubes. There were no significant differences in mean (+/-SD) scores favoring early versus delayed treatment on any of 30 measures, including the Wechsler Full-Scale Intelligence Quotient (98+/-13 vs. 98+/-14); Number of Different Words test, a measure of word diversity (183+/-36 vs. 175+/-36); Percentage of Consonants Correct-Revised test, a measure of speech-sound production (96+/-2 vs. 96+/-3); the SCAN test, a measure of central auditory processing (95+/-15 vs. 96+/-14); and several measures of behavior and emotion. CONCLUSIONS: In otherwise healthy children younger than three years of age who have persistent middle-ear effusion within the duration of effusion that we studied, prompt insertion of tympanostomy tubes does not improve developmental outcomes at six years of age.

Transitioning from analog to digital audio recording in childhood speech sound disorders.

Few empirical findings or technical guidelines are available on the current transition from analog to digital audio recording in childhood speech sound disorders. Of particular concern in the present context was whether a transition from analog- to digital-based transcription and coding of prosody and voice features might require re-standardizing a reference database for research in childhood speech sound disorders. Two research transcribers with different levels of experience glossed, transcribed, and prosody-voice coded conversational speech samples from eight children with mild to severe speech disorders of unknown origin. The samples were recorded, stored, and played back using representative analog and digital audio systems. Effect sizes calculated for an array of analog versus digital comparisons ranged from negligible to medium, with a trend for participants' speech competency scores to be slightly lower for samples obtained and transcribed using the digital system. We discuss the implications of these and other findings for research and clinical practise.

Concurrent and predictive validity of parent reports of child language at ages 2 and 3 years.

The MacArthur-Bates Communicative Development Inventories (CDI; Dale, 1996; Fenson et al., 1994), parent reports about language skills, are being used increasingly in studies of theoretical and public health importance. This study (N = 113) correlated scores on the CDI at ages 2 and 3 years with scores at age 3 years on tests of cognition and receptive language and measures from parent-child conversation. Associations indicated reasonable concurrent and predictive validity. The findings suggest that satisfactory vocabulary scores at age 2 are likely to predict normal language skills at age 3, although some children with limited skills at age 3 will have had satisfactory scores at age 2. Many children with poor vocabulary scores at 2 will have normal skills at 3.