Intelligibility and the acoustic characteristics of speech in amyotrophic lateral sclerosis (ALS)

Digital markers of motor speech impairments in spontaneous speech of patients with ALS-FTD spectrum disorders

OBJECTIVE

To evaluate automated digital speech measures, derived from spontaneous speech (picture descriptions), in assessing bulbar motor impairments in patients with ALS-FTD spectrum disorders (ALS-FTSD).

METHODS

Automated vowel algorithms were employed to extract two vowel acoustic measures: vowel space area (VSA), and mean second formant slope (F2 slope). Vowel measures were compared between ALS with and without clinical bulbar symptoms (ALS + bulbar (n = 49, ALSFRS-r bulbar subscore: x¯ = 9.8 (SD = 1.7)) vs. ALS-nonbulbar (n = 23), behavioral variant frontotemporal dementia (bvFTD, n = 25) without a motor syndrome, and healthy controls (HC, n = 32). Correlations with bulbar motor clinical scales, perceived listener effort, and MRI cortical thickness of the orobuccal primary motor cortex (oral PMC) were examined. We compared vowel measures to speaking rate, a conventional metric for assessing bulbar dysfunction.

RESULTS

ALS + bulbar had significantly reduced VSA and F2 slope than ALS-nonbulbar (|d|=0.94 and |d|=1.04, respectively), bvFTD (|d|=0.89 and |d|=1.47), and HC (|d|=0.73 and |d|=0.99). These reductions correlated with worse bulbar clinical scores (VSA: R = 0.33, p = 0.043; F2 slope: R = 0.38, p = 0.011), greater listener effort (VSA: R=-0.43, p = 0.041; F2 slope: p > 0.05), and cortical thinning in oral PMC (F2 slope: β = 0.0026, p = 0.017). Vowel measures demonstrated greater sensitivity and specificity for bulbar impairment than speaking rate, while showing independence from cognitive and respiratory impairments.

CONCLUSION

Automatic vowel measures are easily derived from a brief spontaneous speech sample, are sensitive to mild-moderate stage of bulbar disease in ALS-FTSD, and may present better sensitivity to bulbar impairment compared to traditional assessments such as speaking rate.

A large-scale comparison of two voice synthesis techniques on intelligibility, naturalness, preferences, and attitudes toward voices banked by individuals with amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) commonly results in the inability to produce natural speech, making speech-generating devices (SGDs) important. Historically, synthetic voices generated by SGDs were neither unique, nor age- or dialect-appropriate, which depersonalized SGD use. Voices generated by SGDs can now be customized via voice banking and should ideally sound uniquely like the individual's natural speech, be intelligible, and elicit positive reactions from communication partners. This large-scale 2 x 2 mixed between- and within-participants design examined perceptions of 831 adult listeners regarding custom synthetic voices created for two individuals diagnosed with ALS via two synthesis systems in common clinical use (waveform concatenation and statistical parametric synthesis). The study explored relationships among synthesis system, dysarthria severity, synthetic speech intelligibility, naturalness, and preferences, and also provided a preliminary examination of attitudes regarding the custom synthetic voices. Synthetic voices generated via statistical parametric synthesis trained on deep neural networks were more intelligible, natural, and preferred than voices produced via waveform concatenation, and were associated with more positive attitudes. The custom synthetic voice created from moderately dysarthric speech was more intelligible than the voice created from mildly dysarthric speech. Clinical implications and factors that may have contributed to the relative intelligibilities are discussed.

PROSA-a multicenter prospective observational study to develop low-burden digital speech biomarkers in ALS and FTD

Objective: There is a need for novel biomarkers that can indicate disease state, project disease progression, or assess response to treatment for amyotrophic lateral sclerosis (ALS) and associated neurodegenerative diseases such as frontotemporal dementia (FTD). Digital biomarkers are especially promising as they can be collected non-invasively and at low burden for patients. Speech biomarkers have the potential to objectively measure cognitive, motor as well as respiratory symptoms at low-cost and in a remote fashion using widely available technology such as telephone calls. Methods: The PROSA study aims to develop and evaluate low-burden frequent prognostic digital speech biomarkers. The main goal is to create a single, easy-to-perform battery that serves as a valid and reliable proxy for cognitive, respiratory, and motor domains in ALS and FTD. The study will be a multicenter 12-months observational study aiming to include 75 ALS and 75 FTD patients as well as 50 healthy controls and build on three established longitudinal cohorts: DANCER, DESCRIBE-ALS and DESCRIBE-FTD. In addition to the extensive clinical phenotyping in DESCRIBE, PROSA collects a comprehensive speech protocol in fully remote and automated fashion over the telephone at four time points. This longitudinal speech data, together with gold standard measures, will allow advanced speech analysis using artificial intelligence for the development of speech-based phenotypes of ALS and FTD patients measuring cognitive, motor and respiratory symptoms. Conclusion: Speech-based phenotypes can be used to develop diagnostic and prognostic models predicting clinical change. Results are expected to have implications for future clinical trial stratification as well as supporting innovative trial designs in ALS and FTD.

Validation of automated pipeline for the assessment of a motor speech disorder in amyotrophic lateral sclerosis (ALS)

Background and objective

Amyotrophic lateral sclerosis (ALS) frequently causes speech impairments, which can be valuable early indicators of decline. Automated acoustic assessment of speech in ALS is attractive, and there is a pressing need to validate such tools in line with best practices, including analytical and clinical validation. We hypothesized that data analysis using a novel speech assessment pipeline would correspond strongly to analyses performed using lab-standard practices and that acoustic features from the novel pipeline would correspond to clinical outcomes of interest in ALS.

Methods

We analyzed data from three standard speech assessment tasks (i.e., vowel phonation, passage reading, and diadochokinesis) in 122 ALS patients. Data were analyzed automatically using a pipeline developed by Winterlight Labs, which yielded 53 acoustic features. First, for analytical validation, data were analyzed using a lab-standard analysis pipeline for comparison. This was followed by univariate analysis (Spearman correlations between individual features in Winterlight and in-lab datasets) and multivariate analysis (sparse canonical correlation analysis (SCCA)). Subsequently, clinical validation was performed. This included univariate analysis (Spearman correlation between automated acoustic features and clinical measures) and multivariate analysis (interpretable autoencoder-based dimensionality reduction).

Results

Analytical validity was demonstrated by substantial univariate correlations (Spearman's ρ > 0.70) between corresponding pairs of features from automated and lab-based datasets, as well as interpretable SCCA feature groups. Clinical validity was supported by strong univariate correlations between automated features and clinical measures (Spearman's ρ > 0.70), as well as associations between multivariate outputs and clinical measures.

Conclusion

This novel, automated speech assessment feature set demonstrates substantial promise as a valid tool for analyzing impaired speech in ALS patients and for the further development of these technologies.

A clinical bulbar assessment scale (CBAS) for amyotrophic lateral sclerosis

INTRODUCTION/AIMS

Comprehensive and valid bulbar assessment scales for use within amyotrophic lateral sclerosis (ALS) clinics are critically needed. The aims of this study are to develop the Clinical Bulbar Assessment Scale (CBAS) and complete preliminary validation.

METHODS

The authors selected CBAS items from among the literature and expert opinion, and content validity ratio (CVR) was calculated. Following consent, the CBAS was administered to a pilot sample of English-speaking adults with El Escorial defined ALS (N = 54) from a multidisciplinary clinic, characterizing speech, swallowing, and extrabulbar features. Criterion validity was assessed by correlating CBAS scores with commonly used ALS scales, and internal consistency reliability was obtained.

RESULTS

Expert raters reported strong agreement for the CBAS items (CVR = 1.00; 100% agreement). CBAS scores yielded a moderate, significant, negative correlation with ALS Functional Rating Scale-Revised (ALSFRS-R) total scores (r = -0.652, p < .001), and a strong, significant, negative correlation with ALSFRS-R bulbar subscale scores (r = -0.795, p < .001). There was a strong, significant, positive correlation with Center for Neurologic Studies Bulbar Function Scale (CNS-BFS) scores (r = 0.819, p < .001). CBAS scores were significantly higher for bulbar onset (mean = 38.9% of total possible points, SD = 22.6) than spinal onset (mean = 18.7%, SD = 15.8; p = .004). Internal consistency reliability (Cronbach's alpha) values were: (a) total CBAS, α = 0.889; (b) Speech subscale, α = 0.903; and (c) Swallowing subscale, α = 0.801.

DISCUSSION

The CBAS represents a novel means of standardized bulbar data collection using measures of speech, swallowing, respiratory, and cognitive-linguistic skills. Preliminary evidence suggests the CBAS is a valid, reliable scale for clinical assessment of bulbar dysfunction.

The efficacy of acoustic-based articulatory phenotyping for characterizing and classifying four divergent neurodegenerative diseases using sequential motion rates

Despite the impacts of neurodegeneration on speech function, little is known about how to comprehensively characterize the resulting speech abnormalities using a set of objective measures. Quantitative phenotyping of speech motor impairments may have important implications for identifying clinical syndromes and their underlying etiologies, monitoring disease progression over time, and improving treatment efficacy. The goal of this research was to investigate the validity and classification accuracy of comprehensive acoustic-based articulatory phenotypes in speakers with distinct neurodegenerative diseases. Articulatory phenotypes were characterized based on acoustic features that were selected to represent five components of motor performance: Coordination, Consistency, Speed, Precision, and Rate. The phenotypes were first used to characterize the articulatory abnormalities across four progressive neurologic diseases known to have divergent speech motor deficits: amyotrophic lateral sclerosis (ALS), progressive ataxia (PA), Parkinson's disease (PD), and the nonfluent variant of primary progressive aphasia and progressive apraxia of speech (nfPPA + PAOS). We then examined the efficacy of articulatory phenotyping for disease classification. Acoustic analyses were conducted on audio recordings of 217 participants (i.e., 46 ALS, 52 PA, 60 PD, 20 nfPPA + PAOS, and 39 controls) during a sequential speech task. Results revealed evidence of distinct articulatory phenotypes for the four clinical groups and that the phenotypes demonstrated strong classification accuracy for all groups except ALS. Our results highlight the phenotypic variability present across neurodegenerative diseases, which, in turn, may inform (1) the differential diagnosis of neurological diseases and (2) the development of sensitive outcome measures for monitoring disease progression or assessing treatment efficacy.

Orofacial Muscle Strength across the Dysarthrias

This study compared orofacial muscle strength between normal and dysarthric speakers and across types of dysarthria, and examined correlations between strength and dysarthria severity. Participants included 79 speakers with flaccid, spastic, mixed spastic–flaccid, ataxic, or hypokinetic dysarthria and 33 healthy controls. Maximum pressure generation (Pmax) by the tongue, lips, and cheeks represented strength. Pmax was lower for speakers with mixed spastic–flaccid dysarthria for all tongue and lip measures, as well as for speakers with flaccid or spastic dysarthria for anterior tongue elevation and lip compression. Anterior tongue elevation and cheek compression tended to be lower than normal for the hypokinetic group. Pmax did not differ significantly between controls and speakers with ataxic dysarthria on any measure. Correlations were generally weak between dysarthria severity and orofacial weakness but were stronger in the dysarthria groups with more prominent orofacial weakness. The results generally support predictions that orofacial weakness accompanies flaccid and/or spastic dysarthria but not ataxic dysarthria. The findings support including type of dysarthria as a variable of interest when examining orofacial weakness in motor speech disorders.

Speech intelligibility loss due to amyotrophic lateral sclerosis: the effect of tongue movement reduction on vowel and consonant acoustic features

The purpose of this study was to identify aspects of impaired tongue motor performance that limit the ability to produce distinct speech sounds and contribute to reduced speech intelligibility in individuals with dysarthria secondary to amyotrophic lateral sclerosis (ALS). We analyzed simultaneously recorded tongue kinematic and acoustic data from 22 subjects during three target words (cat, dog, and took). The subjects included 11 participants with ALS and 11 healthy controls from the X-ray microbeam dysarthria database (Westbury, 1994). Novel measures were derived based on the range and speed of relative movement between two quasi-independent regions of the tongue - blade and dorsum - to characterize the global pattern of tongue dynamics. These "whole tongue" measures, along with the range and speed of single tongue regions, were compared across words, groups (ALS vs. control), and measure types (whole tongue vs. tongue blade vs. tongue dorsum). Reduced range and speed of both global and regional tongue movements were found in participants with ALS relative to healthy controls, reflecting impaired tongue motor performance in ALS. The extent of impairment, however, varied across words and measure types. Compared with the regional tongue measures, the whole tongue measures showed more consistent disease-related changes across the target words and were more robust predictors of speech intelligibility. Furthermore, these whole tongue measures were correlated with various word-specific acoustic features associated with intelligibility decline in ALS, suggesting that impaired tongue movement likely contributes to reduced phonetic distinctiveness of both vowels and consonants that underlie speech intelligibility decline in ALS.

Assessment of dysarthria and dysphagia in patients with amyotrophic lateral sclerosis: Review of the current evidence

Bulbar dysfunction is a common presentation of amyotrophic lateral sclerosis (ALS) and significantly impacts quality of life of people with ALS (PALS). The current paper reviews measurements of dysarthria and dysphagia specific to ALS to identify efficient and valid assessment measures. Using such assessment measures will lead to improved management of bulbar dysfunction in ALS. Measures reviewed for dysarthria in PALS are organized into three categories: acoustic, kinematic, and strength. A set of criteria are used to evaluate the effectiveness of the measures' identification of speech impairments, measurement of functional verbal communication, and clinical applicability. Assessments reviewed for dysphagia in PALS are organized into six categories: patient reported outcomes, dietary intake, pulmonary function and airway defense capacity, bulbar function, dysphagia/aspiration screens, and instrumental evaluations. Measurements that have good potential for clinical use are highlighted in both topic areas. Additionally, areas of improvement for clinical practice and research are identified and discussed. In general, no single speech measure fulfilled all the criteria, although a few measures were identified as potential diagnostic tools. Similarly, few objective measures that were validated and replicated with large sample sizes were found for diagnosis of dysphagia in PALS. Importantly, clinical applicability was found to be limited; thus, a collaborative team focused on implementation science would be helpful to improve the clinical uptake of assessments. Overall, the review highlights the need for further development of clinically viable and efficient measurements that use a multidisciplinary approach.

Spatiotemporal Control of Articulation During Speech and Speechlike Tasks in Amyotrophic Lateral Sclerosis

Purpose This study examined the articulatory control of speech and speechlike tasks in individuals with amyotrophic lateral sclerosis (ALS) and neurologically healthy individuals with the aim to identify the most useful set of articulatory features and tasks for assessing bulbar motor involvement in ALS. Method Tongue and jaw kinematics were recorded in 12 individuals with bulbar ALS and 10 healthy controls during a speech task and two speechlike tasks (i.e., alternating motion rate [AMR], sequential motion rate [SMR]). Eight articulatory features were derived for each participant per task, including the range, maximum speed, and acceleration time of tongue and jaw movements as well as the coupling and timing between tongue and jaw movements. The effects of task (i.e., AMR, SMR, speech) and group (i.e., ALS, control) on these articulatory features were evaluated. For each feature, the task that yielded the largest difference between the ALS and control groups was identified. The diagnostic efficacy of these task-specific features was assessed using the receiver operating characteristic analysis; the relation of these task-specific features to a well-established bulbar severity index-speaking rate-was determined using Spearman's rank correlation. Results Seven task-specific articulatory features were identified, including (a) tongue and jaw acceleration time during the AMR task, (b) tongue-jaw coupling during the SMR task, and (c) range of tongue movement, maximum tongue and jaw speed, and temporal lag between tongue and jaw movements during the speech task. Among these features, tongue and jaw acceleration time and their temporal lag showed relatively high accuracy (i.e., 0.83-0.95) in differentiating individuals with ALS from healthy controls. Range of tongue movement and maximum tongue and jaw speed showed significant correlations with speaking rate. Conclusion Findings provided preliminary evidence for the utility of task-specific articulatory measurements as a novel quantitative assessment to detect and predict bulbar motor involvement in ALS.

Comparison of Automated Acoustic Methods for Oral Diadochokinesis Assessment in Amyotrophic Lateral Sclerosis

Purpose The purpose of this research note is to provide a performance comparison of available algorithms for the automated evaluation of oral diadochokinesis using speech samples from patients with amyotrophic lateral sclerosis (ALS). Method Four different algorithms based on a wide range of signal processing approaches were tested on a sequential motion rate /pa/-/ta/-/ka/ syllable repetition paradigm collected from 18 patients with ALS and 18 age- and gender-matched healthy controls (HCs). Results The best temporal detection of syllable position for a 10-ms tolerance value was achieved for ALS patients using a traditional signal processing approach based on a combination of filtering in the spectrogram, Bayesian detection, and polynomial thresholding with an accuracy rate of 74.4%, and for HCs using a deep learning approach with an accuracy rate of 87.6%. Compared to HCs, a slow diadochokinetic rate (p < .001) and diadochokinetic irregularity (p < .01) were detected in ALS patients. Conclusions The approaches using deep learning or multiple-step combinations of advanced signal processing methods provided a more robust solution to the estimation of oral DDK variables than did simpler approaches based on the rough segmentation of the signal envelope. The automated acoustic assessment of oral diadochokinesis shows excellent potential for monitoring bulbar disease progression in individuals with ALS.

The Effect of Tongue-Jaw Coupling on Phonetic Distinctiveness of Vowels in Amyotrophic Lateral Sclerosis

Purpose The aim of this study was to determine the relation of tongue-jaw coupling to phonetic distinctiveness of vowels in persons at different stages (i.e., early, middle, late) of bulbar motor involvement in amyotrophic lateral sclerosis (ALS) and healthy controls. Method The pattern of spatial tongue-jaw coupling was derived from 11 individuals with ALS and 11 healthy controls using the parallel factor analysis. Two articulatory components, which correspond to tongue displacement independent of the jaw (iTongue) and jaw contribution to tongue displacement (cJaw), were extracted from the composite tongue-jaw displacement. These articulatory components were correlated with F1 (i.e., height) and F2-F1 (i.e., advancement) of 4 vowels (/i/, /u/, /æ/, and /ɔ/) across all participants in each group. In addition, a comprehensive index of functional tongue-jaw coupling was derived as the ratio of cJaw/(iTongue + cJaw), and an acoustic index of vowel distortion (VowelDis) was derived to quantify the overall disease-related changes in phonetic distinctiveness of vowels. Based on these indices, disease-related changes in tongue-jaw coupling and phonetic distinctiveness of vowels were examined in individuals at the early, middle, and late stages of the disease. Results For healthy controls, both iTongue and cJaw contributed to F2-F1, while only cJaw contributed to F1. For individuals with ALS, both iTongue and cJaw contributed to F1, whereas only cJaw contributed to F2-F1. Disease-related changes in tongue-jaw coupling included (a) an overall decrease of the percent contribution of the tongue to the composite tongue-jaw displacement accompanied by an increase of percent contribution of the jaw and (b) several changes in the direction of tongue and jaw displacements occurred at different stages of the disease. These disease-related changes in tongue-jaw coupling had various impacts on phonetic distinctiveness of vowels, resulting in (a) a backward shift of front vowels and reduced front-back vowel contrasts, which occurred early and throughout the disease stages; (b) raising of all vowels during the middle stage of the disease; and (c) reduced high-low vowel contrasts during the late stage of the disease. Overall, phonetic distinctiveness of vowels deteriorated progressively throughout the disease course. Conclusions Different from healthy controls who established optimal functional coupling between the tongue and the jaw during vowel productions, individuals at the early-to-middle stages of bulbar ALS showed various adaptive changes in tongue-jaw coupling in response to the disease-related biomechanical and muscular changes in the articulators (particularly in the tongue). These adaptive changes in tongue-jaw coupling were found to be partially effective in mitigating the negative effect of articulatory involvement on phonetic distinctiveness of vowels. As the disease progressed to the late stage, such adaptations appeared to be no longer evident, resulting in a substantial overall reduction of vowel contrasts.

Analyzing progression of motor and speech impairment in ALS

Amyotrophic lateral sclerosis (ALS) is a degenerative disease which causes death of neurons controlling voluntary muscles. It is currently assessed with subjective clinical measurements, but it would benefit from alternative surrogate biomarkers that can better estimate disease progression. This work analyzes speech and fine motor coordination of subjects recruited by the Answer ALS foundation using data from a mobile app. In addition, clinical variables such as speech, writing and total ALSFRS-R scores are also acquired along with forced and slow vital capacity. Cross-sectional and longitudinal analyses were performed using speech and fine motor features. Results show that both types of features are useful to infer clinical variables especially for males (R²=0.79 for ALSFRS-R total score), but their initial values are not helpful to predict speech and motor decline. However, we found that longitudinal progression for bulbar and spinal ALS onset are different and they can be identified with high accuracy by the extracted features.

Influence of Lineage-Negative Stem Cell Therapy on Articulatory Functions in ALS Patients

Introduction

Amyotrophic lateral sclerosis (ALS) is a fatal, neurodegenerative disease, leading to loss of muscle strength and motor control. Impaired speech and swallowing lower the quality of life and consequently may induce acute respiratory failure. Bone marrow-derived stem and progenitor cells (SPCs) may be a valuable source of trophic factors. In this study, we assessed whether adjuvant cellular therapy could affect the levels of selected neurotrophins and proinflammatory factors in the cerebrospinal fluid (CSF) and subsequently prevent the deterioration of articulation.

Materials and Methods

The study group consisted of 32 patients with sporadic ALS who underwent autologous lineage-negative (Lin⁻) stem cell intrathecal administration to the spinal canal. Lin⁻ cells were aspirated from the bone marrow and isolated using immunomagnetic beads and a lineage cell depletion kit. Patients were examined for articulatory functions by means of the Voice Handicap Index (VHI) questionnaire and Frenchay Dysarthria Assessment (FDA). In parallel, we carried out the analysis of selected trophic and proinflammatory factors in CSF utilizing multiplex fluorescent bead-based immunoassays.

Results

Of the 32 patients who received the Lin⁻ progenitor cell therapy, 6 (group I) showed improvement in articulatory functions, 23 remained stable (group II), and 3 deteriorated (group III) on the 28^th day. The improvement was particularly noticeable in a better cough reflex, laryngeal time, and dribble reflex. A statistically significant lower level of brain-derived neurotrophic factor (BDNF) was observed on day 0 in group I compared to group II. The CSF concentrations of C-reactive protein (CRP) in group I significantly decreased 7 days after Lin⁻ SPC transplantation. On the contrary, a significant increase in the tumor necrosis factor receptor (TNF-R) level was confirmed among patients from group I with improvement of dribble and coughing reflex, tongue movements, and respiration on the 7^th day, as well as on day 28 including dribble reflex solely.

Conclusions

An application of Lin⁻ stem cells could potentate the beneficial humoral effect. The prevention of deterioration of articulatory functions in ALS patients after applying adjuvant Lin⁻ stem cell therapy seems to be promising. Although the procedure is safe and feasible, it requires further in-depth studies.

Predicting Speech Intelligibility Decline in Amyotrophic Lateral Sclerosis Based on the Deterioration of Individual Speech Subsystems

Purpose

To determine the mechanisms of speech intelligibility impairment due to neurologic impairments, intelligibility decline was modeled as a function of co-occurring changes in the articulatory, resonatory, phonatory, and respiratory subsystems.

Method

Sixty-six individuals diagnosed with amyotrophic lateral sclerosis (ALS) were studied longitudinally. The disease-related changes in articulatory, resonatory, phonatory, and respiratory subsystems were quantified using multiple instrumental measures, which were subjected to a principal component analysis and mixed effects models to derive a set of speech subsystem predictors. A stepwise approach was used to select the best set of subsystem predictors to model the overall decline in intelligibility.

Results

Intelligibility was modeled as a function of five predictors that corresponded to velocities of lip and jaw movements (articulatory), number of syllable repetitions in the alternating motion rate task (articulatory), nasal airflow (resonatory), maximum fundamental frequency (phonatory), and speech pauses (respiratory). The model accounted for 95.6% of the variance in intelligibility, among which the articulatory predictors showed the most substantial independent contribution (57.7%).

Conclusion

Articulatory impairments characterized by reduced velocities of lip and jaw movements and resonatory impairments characterized by increased nasal airflow served as the subsystem predictors of the longitudinal decline of speech intelligibility in ALS. Declines in maximum performance tasks such as the alternating motion rate preceded declines in intelligibility, thus serving as early predictors of bulbar dysfunction. Following the rapid decline in speech intelligibility, a precipitous decline in maximum performance tasks subsequently occurred.

Oral motor functions, speech and communication before a definitive diagnosis of amyotrophic lateral sclerosis

The aim of this study was to explore the cranial nerve symptoms, speech disorders and communicative effectiveness of Finnish patients with diagnosed or possible amyotrophic lateral sclerosis (ALS) at their first assessment by a speech-language pathologist. The group studied consisted of 30 participants who had clinical signs of bulbar deterioration at the beginning of the study. They underwent a thorough clinical speech and communication examination. The cranial nerve symptoms and ability to communicate were compared in 14 participants with probable or definitive ALS and in 16 participants with suspected or possible ALS. The initial type of ALS was also assessed. More deterioration in soft palate function was found in participants with possible ALS than with diagnosed ALS. Likewise, a slower speech rate combined with more severe dysarthria was observed in possible ALS. In both groups, there was some deterioration in communicative effectiveness. In the possible ALS group the diagnostic delay was longer and speech therapy intervention actualized later. The participants with ALS showed multidimensional decline in communication at their first visit to the speech-language pathologist, but impairments and activity limitations were more severe in suspected or possible ALS. The majority of persons with bulbar-onset ALS in this study were in the latter diagnostic group. This suggests that they are more susceptible to delayed diagnosis and delayed speech therapy assessment. It is important to start speech therapy intervention during the diagnostic processes particularly if the person already shows bulbar symptoms.

Relationship between kinematics, F2 slope and speech intelligibility in dysarthria due to cerebral palsy

A multimodal approach combining acoustics, intelligibility ratings, articulography and surface electromyography was used to examine the characteristics of dysarthria due to cerebral palsy (CP). CV syllables were studied by obtaining the slope of F2 transition during the diphthong, tongue-jaw kinematics during the release of the onset consonant, and the related submental muscle activities and relating these measures to speech intelligibility. The results show that larger reductions of F2 slope are correlated with lower intelligibility in CP-related dysarthria. Among the three speakers with CP, the speaker with the lowest F2 slope and intelligibility showed smallest tongue release movement and largest jaw opening movement. The other two speakers with CP were comparable in the amplitude and velocity of tongue movements, but one speaker had abnormally prolonged jaw movement. The tongue-jaw coordination pattern found in the speakers with CP could be either compensatory or subject to an incompletely developed oromotor control system.

Basic parameters of articulatory movements and acoustics in individuals with Parkinson's disease

It has long been recognized that lesions of the basal ganglia frequently result in dysarthria, in part because many individuals with Parkinson's disease (PD) have impaired speech. Earlier studies of speech production in PD using perceptual, acoustic, and/or kinematic analyses have yielded mixed findings about the characteristics of articulatory movements underlying hypokinetic dysarthria associated with PD: in some cases reporting reduced articulatory output, and in other instances revealing orofacial movement parameters within the normal range. The central aim of this experiment was to address these inconsistencies by providing an integrative description of basic kinematic and acoustic parameters of speech production in individuals with PD. Recordings of lip and jaw movements and acoustic data were collected in 16 individuals with PD and 16 age- and sex-matched neurologically healthy older adults. Our results revealed a downscaling of articulatory dynamics in the individuals with PD, evidenced by decreased amplitude and velocity of lower lip and jaw movements, decreased vocal intensity (dB sound pressure level [SPL]), and reduced second formant (F2) slopes. However, speech rate did not differ between groups. Our finding of an overall downscaling of speech movement and acoustic parameters in some participants with PD provides support for speech therapies directed at increasing speech effort in individuals with PD.

Differentiating profiles of speech impairments in Friedreich's ataxia: a perceptual and instrumental approach

BACKGROUND

The speech disorder associated with Friedreich's ataxia (FRDA) is classically described as ataxic dysarthria. However, variable neuropathology beyond the cerebellum, which may include the corticospinal and corticobulbar tracts, means that the dysarthria can be mixed rather than a pure ataxic dysarthria.

AIMS

To characterize physiological features of the dysarthria associated with FRDA and identify differential patterns of deviation that may occur across the subsystems of the speech-production mechanism in a series of seven case studies.

METHODS & PROCEDURES

The assessment battery included a perceptual analysis of a speech sample using an interval rating scale, and a range of instrumental measures to investigate the respiratory, laryngeal, velopharyngeal and articulatory systems.

OUTCOMES & RESULTS

The results demonstrated the variability that exists in the dysarthria associated with FRDA, highlighting the existence of differential profiles of speech impairment. A particular distinction was observed between the presence of hypernasality and phonatory dysfunction, as evidenced by the instrumental results.

CONCLUSIONS & IMPLICATIONS

The distinct profiles of dysarthria associated with FRDA indicate that approaches that address multiple subsystems are necessary for the accurate characterization and quantification of the motor speech disorder. Further research is required to investigate the decline in speech function as the disease progresses, as changes in speech function over time may be a good indicator of neurological decline in FRDA.

An acoustic study of the relationships among neurologic disease, dysarthria type, and severity of dysarthria

PURPOSE

This study examined acoustic predictors of speech intelligibility in speakers with several types of dysarthria secondary to different diseases and conducted classification analysis solely by acoustic measures according to 3 variables (disease, speech severity, and dysarthria type).

METHOD

Speech recordings from 107 speakers with dysarthria due to Parkinson's disease, stroke, traumatic brain injury, and multiple system atrophy were used for acoustic analysis and for perceptual judgment of speech intelligibility. Acoustic analysis included 8 segmental/suprasegmental features: 2nd formant frequency slope, articulation rate, voiceless interval duration, 1st moment analysis for fricatives, vowel space, F0, intensity range, and Pairwise Variability Index.

RESULTS

The results showed that (a) acoustic predictors of speech intelligibility differed slightly across diseases and (b) classification accuracy by dysarthria type was typically worse than by disease type or severity.

CONCLUSIONS

These findings were discussed with respect to (a) the relationship between acoustic characteristics and speech intelligibility and (b) dysarthria classification.

[Phoniatric and laryngologic symptoms in motor neuron disease (MND)]

INTRODUCTION

Motor neuron disease is a progressive neurologic disorder characterized by degeneration of motor neurons in the cerebral cortex, brain stem and spinal cord.

THE AIM OF THIS STUDY

Was to present methods of therapy and rehabilitation in patients with MND and the role of phoniatrician and otolaryngologist in diagnostic and therapeutic process. MATERIAL AND METHOD, RESULTS: The material of present study consists of 3 patients in the age of 38 to 55 who were admitted to The Institute of Physiology and Pathology of Hearing in Warsaw, Poland. Patients underwent laryngological, phoniatric and neurologopedics examinations. They were treated with phoniatric and logopedics rehabilitation strategy applying manual therapy of voice, speech exercises and courses of physiotherapy. As a result of therapeutical management, quality of speech and voice were improved.

CONCLUSIONS

1. Disorders of voice and speech may be early symptoms of motor neuron disease; 2. Patients with motor neuron disease require multidisciplinary therapy, including otolaryngologists and phoniatricians; 3. Acoustic analysis of voice (MDVP) presents more often disorders in frequency range than amplitude changes; 4. Intensive and regular excercises are crucial for the improvement in speech communication.

Dysarthria in amyotrophic lateral sclerosis: A review

Dysarthria is a motor disorder of speech characterized by abnormalities of the articulation and intelligibility of speech. Phonation and the rate of facial movements may also be affected. Understanding the nature and course of dysarthria in amyotrophic lateral sclerosis (ALS) is important because loss of communication prevents patients from participating in many activities, may lead to social isolation, and reduces the quality of life. The goal of management of dysarthria in ALS patients is to optimize communication effectiveness for as long as possible. The information about dysarthria in ALS is dispersed in physiological, pathological, speech therapy, otorhinolaringological and neurological publications. This review summarizes the current state of knowledge on the clinical features, differential diagnosis, pathophysiology, investigations and management of dysarthria in ALS patients. There is a need to compare the different methods used to assess dysarthria and for controlled clinical trials to assess therapeutic strategies.

Kinematics of disease progression in bulbar ALS

The goal of this study was to investigate the deterioration of lip and jaw movements during speech longitudinally in three individuals diagnosed with bulbar amyotrophic lateral sclerosis (ALS). The study was motivated by the need to understand the relationship between physiologic changes in speech movements and clinical measures of speech performance such as speaking rate and speech intelligibility. Movements of the lip and jaw were quantified with respect to their size speed, and duration. The data revealed several changes in lip and jaw movement that coincided with ALS progression. In two out of three speakers, the changes in measures of path distance and speed anticipated the drop in speech intelligibility by approximately 3 months. With disease progression, increases in movement duration coincided with declines in speech intelligibility. Overall, the movement measures appeared to be sensitive to disease progression in ALS.

LEARNING OUTCOMES

By the end of the manuscript, the reader should be able to: (1) describe the changes that occur in articulatory movements of the jaw and lower lip in ALS; (2) understand the relationship between physiologic measures of movement and speech intelligibility and speaking rate; (3) identify critical points in the disease progression and understand which quantitative measures reveal the state of the bulbar system at these time points.

Communication strategies of people with ALS and their partners

There are wider issues relating to the communication difficulties experienced by people with amyotrophic lateral sclerosis (ALS) than simply the physical problems caused by diminished oral control. In addition, existing literature on ALS rarely considers communication to be a joint interaction which depends on the strategies adopted by both communication partners, nor does it present communication in real life settings. This paper presents some of the findings from a 3-year research project which investigated the communication of people with ALS and their partners in their own homes. It discusses the purpose of human communication, and through examination of conversations in people's own homes has identified a range of strategies and techniques that families with ALS employ. For some people with ALS, although speech may deteriorate, they are still able to communicate closely and in a way that is more focused on topics that are particularly important to them. The findings from this study will be of interest to those who work with people with ALS.

Phonarticulatory diadochokinesis in young and elderly individuals

The phonoarticulatory diadochokinesis test has been recommended to evaluate neurological disorders. It is a speech task that consists of the ability to repeat at high speed a segment of speech. The purpose of this research is to analyze the diadochokinesia rate of adults from two distinct age groups. 23 young aice and speech analysis software Visi-Pitch III/Sona-Speech, KayElemetrics. Both groups presented with reduced diadochokinesia rate as the speech production became more complex. The young adults group presented with higher diadochokinesia rate in adults and 23 elderly people, both sexes participated in this study. Each participant produced the /pa/, /ta/, /ka/ syllables, the vowel /a/ and the /pataka/ sequence, as fast and as long as they could with habitual pitch and loudness. The speech samples were analyzed by using the voll speech tasks while the elderly adults group had a worse intensity control.

Examining the effects of multiple sclerosis on speech production: does phonetic structure matter?

The second formant (F2) is well-known to be important to intelligibility (e.g. [Delattre, P., Liberman, A., & Cooper, F. (1955). Acoustic loci and transitional cues for consonants. Journal of the Acoustical Society of America, 27, 769-774]) and is affected by a variety of dysarthrias [Weismer, G., & Martin, R. (1992). Acoustic and perceptual approaches to the study of intelligibility. In R. Kent (Ed.), Intelligibility in speech disorders (pp. 67-118). Amsterdam: John Benjamins Publishing Company]. This study tests two related hypotheses: (1) dysarthria associated with Multiple Sclerosis (MS) has a greater effect on the ability to produce extreme F2 movement than on typical F2 movement and (2) phonetic stimuli associated with large and/or rapid F2 movement in healthy speakers precipitate larger differences between healthy and dysarthric speech than do stimuli associated with small and/or slow F2 movement. Twelve participants with MS and 16 healthy controls read aloud the Grandfather Passage. F2 slopes were calculated from the F2 tracings (i.e. change in Hz over a 20ms lag). For each sentence, the following measures of F2 movement were calculated: F2 range (maximum F2-minimum F2), median slope, and 95%ile slope. The mean and the maximum observation for each participant were respectively used as measures of typical and extreme productions. A repeated-measures MANOVA detected significantly larger group differences in the slopes of maximum productions than for mean production. Also, group differences in F2 slope were greater in phonetic stimuli associated with the largest F2 slopes in healthy speech than in phonetic stimuli associated with more shallow slopes. No group differences in F2 range were detected. Results indicate dysarthria affects the production of extremely rapid changes in F2 and that some phonetic structures are more useful than others for detecting these impairments. It is concluded that comparison of speakers' best-productions (e.g. maximum F2 slope) yield more useful estimates of the effects of mild to moderate dysarthria on F2 slopes than do typical productions.

LEARNING OUTCOMES

The reader will be able to: (1) describe two approaches to measuring typical and extreme acoustic variability that can be applied to connected speech, (2) discuss evidence that MS affects extremely rapid changes in F2.

Comparison of Speaking Rate, Articulation Rate and Alternating Motion Rate in Dysarthric Speakers

Despite recent indications that speaking rate, articulation rate and alternating motion rate (AMR) are sensitive to the influence of neurological disease on speech production in dysarthric speakers, the relationship among these parameters remains largely questionable. In the current study, speech samples were collected from 62 dysarthric speakers and 34 controls while reading a passage. Acoustic analysis investigated speaking rate, articulation rate and AMR and compared these parameters between the dysarthric and control groups and within the control and dysarthric group. The major findings were: (1) Speaking rate, articulation rate and AMR were all markedly lower in dysarthric speakers than in controls. (2) Marked correlations were recognized between speaking rate, articulation rate and AMR in the dysarthric group. (3) Compared with the speaking rate and articulation rate, AMR is characterized as follows: (i) variation was more limited in controls, and (ii) the control group was clearly distinguishable from the dysarthric group. (4) Unlike in controls, AMR in the dysarthric speakers was notably lower than their articulation rate. We therefore conclude that AMR is a more easily detected sign of abnormal articulation than speaking rate and articulation rate.

Breath-group intelligibility in dysarthria: characteristics and underlying correlates

PURPOSE

This study was designed to determine whether within-speaker fluctuations in speech intelligibility occurred among speakers with dysarthria who produced a reading passage, and, if they did, whether selected linguistic and acoustic variables predicted the variations in speech intelligibility.

METHOD

Participants with dysarthria included a total of 10 persons with Parkinson's disease and amyotrophic lateral sclerosis; a control group of 10 neurologically normal speakers was also studied. Each participant read a passage that was subsequently separated into consecutive breath groups for estimates of individual breath group intelligibility. Sixty listeners participated in 2 perceptual experiments, generating intelligibility scores across speakers and for each breath group produced by speakers with dysarthria.

RESULTS

Individual participants with dysarthria had fluctuations in intelligibility across breath groups. Breath groups of participants with dysarthria had fewer average words and reduced interquartile ranges for the 2nd formant, the latter a global measure of articulatory mobility. Regression analyses with intelligibility measures as the criterion variable and linguistic and acoustic measures as predictor variables produced significant functions both within and across speakers, but the solutions were not the same.

CONCLUSIONS

Linguistic or acoustic variables that predict across-speaker variations in speech intelligibility may not function in the same way when within-speaker variations in intelligibility are considered.

Acoustic differences between content and function words in amyotrophic lateral sclerosis

Studies describing acoustic characteristics of speech produced by individuals with dysarthria may help to explain intelligibility deficits for these speakers. One goal of the current study was to investigate the manner and extent to which nine speakers with mild to moderate dysarthria associated with amyotrophic lateral sclerosis (ALS) and nine healthy speakers acoustically distinguished /i/, /ae/, /u/, and /a/ in content and function words. A further aim was to evaluate the relationship between impaired speech in ALS and the magnitude of acoustic differences for vowels in content and function words. Speakers read the Farm Passage at a comfortable or habitual rate. F1 and F2 midpoint frequencies were measured, and vowel space areas were calculated. Vowel durations also were measured. The magnitude of F1, F2, vowel space area, and duration differences for vowels in content and function words was not statistically different for speakers with ALS and healthy controls. In addition, with the exception of /i/ produced by some speakers with ALS, vowel duration tended to be shorter in function words. Average F1 and F2 values for function words also tended to be centralized relative to content words. Although vowel space area differences for the two speaker groups were not statistically significant, there was a tendency for the difference in vowel space area for content and function words to be smaller for speakers with ALS than for controls. Regression analyses further indicated that the magnitude of temporal differences for vowels in content and function words was a better predictor of impaired speech than the magnitude of spectral differences for vowels in content and function words. One clinical implication is that individuals with ALS may benefit from therapy techniques targeting temporal properties of the acoustic signal.

Segmental timing in amyotrophic lateral sclerosis

This study describes segmental timing patterns for a passage read by speakers with ALS and a group of age- and gender-matched neurologically healthy speakers. Segment durations for ALS speakers' habitual rates (ALS condition) were compared to segment durations for healthy speakers' habitual and slow reading rates (Control Habitual and Control Slow conditions). Temporal differences for pairs of sound classes (i.e., long-short vowels, voiceless-voiced fricatives, voiceless-voiced stop gaps, high-low vowels) and prepausal lengthening of vowels also were studied. The results of the ALS-Control Habitual comparison suggested that the slowed articulatory rate of ALS influences segmental timing for most phonetic events. The finding that local segmental cues for disordered speakers were broadly consistent with their overall (slow) articulatory rate suggests that duration likely does not contribute in a significant way to intelligibility deficits in ALS. A qualitative analysis further indicated that the slowed rate of ALS is not uniformly distributed across phonetic events, but influences segment durations of particular sound categories in ways consistent with the disease process. The analysis comparing segment durations for the ALS and Control Slow conditions suggested that the overall pattern of segmental timing for speakers with ALS was broadly similar to the pattern for voluntarily slowed speech of healthy talkers. Finally, temporal differences for sound classes (i.e., voiceless-voiced fricatives, long-short vowels) and prepausal lengthening for speakers with ALS typically were similar to healthy speakers' habitual and slow speech. There were substantial variability within speaker groups and reversals of expected effects, however. The implication is that temporal differences for sound classes, such as short and long vowels, are not a particularly reliable perceptual cue for listeners.

Formant transition duration and place perception in misarticulating children and adolescents

The explanation of articulatory problems as an output speech disorder does not preclude the possibility that auditory processing problems are associated. Identification of brief auditory spectral cues in a place-of-articulation continuum was studied in children with articulation problems. First, it was shown that formant transition durations smaller than 20·0 ms dramatically decreased phonemic identification rates for alveolar stop consonants in control subjects. Identification tasks based on two place-of-articulation continua /pαk/-/tαk/ with F2/F3 transition durations of 52 and 20 ms were administered to groups of misarticulating children and adolescents and two control groups (children and adults). For all subject groups there was poorer phonetic processing with shorter transition durations of F2 and F3. The misarticulating subjects demonstrated poorer phonetic processing of formant transitions than did the control subjects. Shortening F2/F3 transition duration did not differentially influence perceptual behaviour between the experimental and the control groups. In determining the causal link between perception and production, an explanation of perception preceding production was favoured. It was argued that, in addition to assessing the specificity between perception and production mechanisms, assessment of perception of formant transitions may have potential as a clinical tool for evaluating phonetic processing.

The influence of speaking rate on vowel space and speech intelligibility for individuals with amyotrophic lateral sclerosis

The relationship between speaking rate, vowel space area, and speech intelligibility was studied in a group of 9 subjects with amyotrophic lateral sclerosis (ALS) and 9 age- and gender-matched controls. Subjects read a standard passage (the Farm Passage) at three speaking rates, including HABITUAL, FAST, and SLOW. Vowel segment durations and target formant frequencies were measured at each speaking rate from select words containing the vowels /i/, /ae/, /a/, and /u/. To quantify changes in vowel space area across speaking rate, the area of the vowel quadrilateral was calculated for each speaker at each speaking rate. In addition, intelligibility estimates at each speaking rate were obtained for the dysarthric speakers. Results revealed that dysarthric speakers exhibited smaller vowel space areas and less systematic changes in vowel space as a function of speaking rate, when compared to the neurologically intact speakers. In an examination of the relationship between vowel space area and speech intelligibility, vowel space was found to account for 45% of the variance in speech intelligibility. This result suggests that vowel space area is an important component of global estimates of speech intelligibility.

Intelligibility and phonetic contrast errors in highly intelligible speakers with amyotrophic lateral sclerosis

Intelligibility data, phonetic contrast errors, and information regarding subsystem involvement were examined in 29 highly intelligible subjects (18 women and 11 men) with amyotrophic lateral sclerosis. Results are discussed in terms of data for individual subjects, the group as a whole, and for subgroups based on dysarthric status and gender. Of particular interest are findings that suggest early laryngeal involvement as well as gender-related differences for several contrasts.