Oral and Laryngeal Diadochokinesis Across the Life Span: A Scoping Review of Methods, Reference Data, and Clinical Applications

Diadochokinesis Performance and Its Link to Cognitive Control: Alternating Versus Non-Alternating Diadochokinesis

PURPOSE

In a previous publication, we observed that maximum speech performance in a nonclinical sample of young adult speakers producing alternating diadochokinesis (DDK) sequences (e.g., rapidly repeating "pataka") was associated with cognitive control: Those with better cognitive switching abilities (i.e., switching flexibly between tasks or mental sets) showed higher DDK accuracy. To follow up on these results, we investigated whether this previously observed association is specific to the rapid production of alternating sequences or also holds for non-alternating sequences (e.g., "tatata").

METHOD

For the same sample of 78 young adults as in our previous study, we additionally analyzed their accuracy and rate performance on non-alternating sequences to investigate whether executive control abilities (i.e., indices of speakers' updating, inhibition, and switching abilities) were more strongly associated with production of alternating, as compared with non-alternating, sequences.

RESULTS

Of the three executive control abilities, only switching predicted both DDK accuracy and rate. The association between cognitive switching (and updating ability) and DDK accuracy was only observed for alternating sequences. The DDK rate model included a simple effect of cognitive switching, such that those with better switching ability showed slower diadochokinetic rates across the board. Thus, those with better cognitive ability showed more accurate (alternating) diadochokinetic production and slower maximum rates for both alternating and non-alternating sequences.

CONCLUSION

These combined results suggest that those with better executive control have better control over their maximum speech performance and show that the link between cognitive control and maximum speech performance also holds for non-alternating sequences.

The Contributions of Pitch, Loudness, and Rate Control to Speech Naturalness in Cerebellar Ataxia

PURPOSE

The goal of this study was to determine the relationship between the perceptual measure of speech naturalness and objective measures of pitch, loudness, and rate control as a potential tool for assessment of ataxic dysarthria.

METHOD

Twenty-seven participants with ataxia and 29 age- and sex-matched control participants completed the pitch glide and loudness step tasks drawn from the Frenchay Dysarthria Assessment-Second Edition (FDA-2) in addition to speech diadochokinetic (DDK) tasks. First, group differences were compared for pitch variability in the pitch glide task, loudness variability in the loudness step task, and syllable duration and speech rate in the DDK task. Then, these acoustic measures were compared with previously collected ratings of speech naturalness by speech-language pathology graduate students.

RESULTS

Robust group differences were measured for pitch variability and both DDK syllable duration and speech rate, indicating that the ataxia group had greater pitch variability, longer DDK syllable duration, and slower DDK speech rate than the control group. No group differences were measured for loudness variability. There were robust relationships between speech naturalness and pitch variability, DDK syllable duration, and DDK speech rate, but not for loudness variability.

CONCLUSIONS

Objective acoustic measures of pitch variability in the FDA-2 pitch glide task and syllable duration and speech rate in the DDK task can be used to validate perceptual measures of speech naturalness. Overall, speech-language pathologists can incorporate both perceptual measures of speech naturalness and acoustic measures of pitch variability and DDK performance for a comprehensive evaluation of ataxic dysarthria.

Is the Articulatory Trajectory of Changing Syllables Important for Achieving Higher Syllable Rates Compared to Repeated Syllables?

PURPOSE

The production of speech-like sequences composed of varying syllables has been reported to achieve higher syllable rates than the production of repeated syllables (commonly designed as sequential motion rate [SMR] and alternating motion rate [AMR] tasks, respectively). The faster rate for SMR relative to AMR sequences is explained by different interpretative hypotheses, which remain empirically unexplored. In the present study, we aimed to investigate whether the high syllable rates of SMR sequences are due to the specific sequences used in most studies that involve front-to-back articulatory movements.

METHOD

Syllable rates of SMR sequences composed of different articulatory trajectories (i.e., labial-alveolar-velar [/pateko/], alveolar-velar-labial [/tekopa/], and velar-labial-alveolar [/kopate/]) were compared with those of the AMR sequences /papapa/, /tetete/, and /kokoko/ in 20 participants.

RESULTS

The results show higher syllable rates for each of the three SMR sequences as compared to AMR, suggesting that the trajectory of the articulatory movements in the sequential sequences is not the key to achieving higher syllable rates.

CONCLUSION

The syllable rate advantage for SMR over AMR sequences is not explained by the articulatory trajectories included in the former task, indicating that the front-to-back movements generally included in SMR sequences (i.e., /pataka/) are not decisive in achieving a higher syllable rate.

Vocal Fold Vibratory Dose and Perceived Exertion Responses to the Fluid Interval Test for Voice (FIT-V): A Novel Vocal Loading Task Platform

INTRODUCTION

Vocal loading tasks are often used to study how specific variables influence downstream vocal effort or fatigue. The current study introduces a novel vocal loading task, the Fluid Interval Test for Voice (FIT-V) that combines laryngeal diadochokinesis, intervallic rest and exercise, and fluid back pressure. To assess the differences between this novel task and existing vocal loading tasks, we measured vocal fold vibratory dose and perceived phonatory exertion across three 30-minute task conditions: a control loud oral reading task (LOR), a back pressure-resisted Fluid Interval Test for Voice (FIT-V5), and an unresisted Fluid Interval Test for Voice (FIT-V0).

METHODS

Following a training session, 30 participants completed the three tasks (LOR, FIT-V0, and FIT-V5) in counterbalanced order on different days. Vocal fold cycle (Aim 1A) and distance doses (Aim 1B) were collected continuously using a dosimeter. The overall perceived phonatory exertion (Aim 2A) was rated once per minute, while anatomically localized cognitive, laryngeal, thoracic, abdominal, and articulatory exertion (Aim 2B) were rated once at the end of each task. Statistical analyses examined the effects of task and task× time interactions on the dependent variables.

RESULTS

The FIT-V0 and FIT-V5 tasks imposed smaller vocal fold cycle doses (P < 0.001; Aim 1A) and distance doses (P < 0.001; Aim 1B) than the LOR task while eliciting comparable or greater magnitudes of overall perceived phonatory exertion (P = 0.003; Aim 2A). However, anatomically localized perceived exertion was greater in the abdomen and thorax (P < 0.05) and lesser in the anterior neck (P < 0.05) in the two FIT-V tasks relative to the LOR task (Aim 2B). Absolute forced vital capacity was a significant predictor of most forms of anatomically localized perceived exertion.

DISCUSSION

The unresisted FIT-V0 and the back pressure-resisted FIT-V5 tasks yielded similar profiles of overall perceived phonatory exertion, despite vocal fold vibratory doses roughly half that of the LOR task. However, the anatomically localized perceived exertion data underscored subtle across-task differences not apparent in the overall ratings, suggesting potentially distinct physiological and perceptual niches for the three task protocols.

Articulatory-based Phonemic Paraphasia in Conduction Aphasia: A Dysfunction in Phoneme-to-Articulation Conversion Uncovered Through Crossed Aphasia

Phonemic paraphasia, a common characteristic of conduction aphasia, has traditionally been attributed to phonological representation dysfunction. An alternative hypothesis posits that phonemic paraphasia arises from difficulty converting phonemes into their corresponding articulatory maneuvers. However, detailed case studies supporting this theory have been lacking. In this report, we present the case of a 61-year-old right-handed man with right temporo-parietal infarction who exhibited crossed aphasia characterized by typical conduction aphasia symptoms (eg, relatively fluent speech with intact comprehension, frequent phonemic paraphasia, and pronounced difficulties in oral repetition) in the absence of distorted articulation, syllable segmentation, and prosody impairment. Despite the frequent occurrence of phonemic paraphasia and articulatory challenges, our patient's phonological representations remained relatively intact. His phonemic paraphasia was often self-corrected to produce correct responses, a feature known as conduit d'approche. During the oral repetition of individual mora (ie, the smallest unit of speech in Japanese), we observed that the patient consistently traced the corresponding Hiragana phonetic symbol accurately, despite his difficulties in articulation. We substantiated this phenomenon through objective assessment and posit that it resulted from an unusual separation of language functions in crossed aphasia-specifically, a disconnection between phonological representations in the right temporo-parietal cortex and speech articulation engrams in the left hemisphere. In this case of conduction aphasia, articulatory-based phonemic paraphasia may be viewed as an inability to convert phonemes into the appropriate articulatory maneuvers rather than as phonological representation dysfunction or apraxia of speech.

Individual Differences in Accent Imitation

All talkers show some flexibility in their speech, and the ability to imitate an unfamiliar accent is a skill that shows vast individual differences. Yet the source of these individual differences, in particular whether they originate from perceptual, motor, or social/personality factors, is not yet clear. In the current study, we ask how individual differences in these factors predict individual differences in deliberate accent imitation. Participants imitated three accents, and attempts were rated for accuracy. A set of measures tracking individual differences in perceptual, motor, cognitive, personality, and demographic factors were also acquired. Imitation ability was related to differences in musical perception, vocal articulation, and the personality characteristic of "openness to experience," and was affected by attitudes towards the imitated talkers. Taken together, results suggest that deliberate accent imitation skill is modulated not only by core perceptual and motor skills, but also by personality and affinity to the talker, suggesting that some aspects of deliberate imitation are a function of domain-general constraints on perceptual-motor systems, while others may be modulated by social context.

Effects of Back Pressure on the Feasibility and Tolerability of Laryngeal Diadochokinetic Exercise: A Pilot Study

BACKGROUND

The term vocal demand response refers to how speakers meet vocal demands. Vocal loading tasks with predetermined demand parameters (duration, pitch, loudness, etc) have been used in research to study the vocal demand response; these have historically consisted of loud sustained vowel and loud speech tasks. Tasks founded on laryngeal diadochokinesis (LDDK) may be viable alternatives, especially if demand parameters such as exercise-rest ratio and fluid back pressure are concurrently modulated.

OBJECTIVES

To explore the effects of four fluid back pressure conditions (0, 5, 10, and 15 cm H2O) on several measures of subjective participant experience, feasibility, and tolerability during intervallic laryngeal diadochokinetic exercise.

METHODS

Participants (n = 12) completed 15-minute trials of LDDK in 30-second rest and exercise intervals against four counterbalanced back pressure conditions: 0, 5, 10, and 15 cm H2O. The effects of back pressure on (1) ratings of perceived vocal exertion, (2) prevalence of adverse effects such as shortness of breath or lightheadedness, (3) subjective difficulty of sustaining LDDK, (4) number of exercise intervals completed, (5) rankings of participant-preferred back pressure levels, and (6) expert ratings of auditory-perceptual diadochokinetic strength were assessed descriptively.

RESULTS

Perceived vocal exertion, lightheadedness, and subjective laryngeal diadochokinetic difficulty increased as back pressure increased. Number of intervals completed, auditory-perceptual diadochokinetic strength, and participant rankings of back pressure conditions, by contrast, decreased as back pressure increased. 0 and 5 cm H2O were the most preferred back pressure conditions overall.

DISCUSSION

Fluid back pressure was feasible and broadly tolerated during 15-minute trials of vocal exercise. However, the transition from 5 → 10 cm H2O appeared to represent an inflection point in our results: a minority of participants did not tolerate exercise at 10 cm H2O, becoming a majority at 15 cm H2O. We conclude that fluid back pressure should be restricted to values between 0 and 10 cm H2O during LDDK.

Relationship between texture perception and oral function: A preliminary study in young, healthy adults

BACKGROUND

Oral frailty, characterised by reduced oral function, is associated with systemic health issues in older adults. Although the criteria for diminished oral function often focus on motor and secretory abilities, texture perception also plays a crucial role in health due to its impact on food intake and palatability.

OBJECTIVE

This study aimed to explore the relationship between thickness discrimination ability (TDA) and oral motor and secretory functions in healthy young individuals.

METHODS

Twenty-eight adults were assessed for texture perception using eight concentrations of aqueous xanthan gum solutions to determine TDA scores. Measurements of occlusal force, masticatory performance, tongue pressure, stimulated salivary flow rate and tongue-lip motor function were conducted. Spearman's correlation analysis was used to evaluate the relationship between TDA scores and oral functions. Participants were divided into high-sensitivity and low-sensitivity groups based on their TDA scores to compare oral function test results.

RESULTS

The TDA scores varied among the participants, with higher scores correlating with higher masticatory performance (r = 0.41, p < .05). Masticatory performance in the high-sensitivity group was significantly higher than in the low-sensitivity group (211.9 ± 59.2 mg/dL vs. 157.9 ± 43.0 mg/dL, p = .013), with no significant differences in other oral functions.

CONCLUSION

Masticatory performance was correlated with TDA, suggesting a link between the selection function of mastication and thickness discrimination. These findings highlight the potential relevance of texture perception in oral function and indicate the need for further exploration, particularly in older adults with declining oral health.

Physical frailty intensifies the positive association of oral frailty with poor global cognitive function and executive function among older adults especially for females: a cross-sectional study

BACKGROUND

Oral frailty is reported to increase the risk of new onset of mild cognitive impairment. Whereas, the association of oral frailty with cognition among older adults in both physical frail and non-physical frail status has not been sufficiently explored, and whether there are sex differences in the association is unclear. This study investigated the association of oral frailty and physical frailty with global cognitive function and executive function among older adults, as well as the sex differences in such association.

METHODS

This cross-sectional study included 307 participants aged ≥ 60 years old from communities between June 2023 and August 2023, in Nanjing, China. Global cognitive function and executive function were assessed by using the Montreal Cognitive Assessment (MoCA) and Trail Making Tests A (TMT-A), respectively. Oral frailty was identified by the combination of natural tooth, Oral Frailty Index-8 (OFI-8), and oral diadochokinesis. Physical frailty was measured by using Fried phenotype model which contained 5 criteria: unintentional weight loss, weakness, exhaustion, slowness, and low physical activity. Multiple linear regression analyses for overall participants and stratified by sex and presence or absence of physical frailty were performed, respectively, to examine the association between oral frailty and cognitive functions.

RESULTS

The median age of participants was 70 years old. The study included 158 (51.5%) females, 53 (17.3%) individuals with physical frailty, and 65 (21.2%) participants with oral frailty. After adjustment, the association between oral frailty and global cognitive function was observed in the physical frailty group (B = -2.67, 95% Confidence Interval [CI]: -5.27 to -0.07, p = 0.045) and the females with physical frailty (B = -4, 95% CI: -7.41 to -0.58, p = 0.024). Oral frailty was associated with executive function in overall participants (B = 0.12, 95% CI: 0.01 to 0.22, p = 0.037), physical frailty group (B = 23.68, 95% CI: 1.37 to 45.99, p = 0.038). In the adjusted models, oral frailty was significantly associated with executive function in all females (B = 0.21, 95% CI: 0.05 to 0.36, p = 0.009), in females without physical frailty (B = 0.19, 95% CI: 0.02 to 0.36, p = 0.027), and in females with physical frailty (B = 48.69, 95% CI: 7.17 to 90.21, p = 0.024).

CONCLUSIONS

Physical frailty intensifies the positive association of oral frailty with poor global cognitive function and executive function among older adults, particularly among females. It is ponderable to consider sex differences and facilitate the management of physical frailty when it comes to promoting cognitive health based on the perspective of oral health among older adults.

The Feel of Speech: Multisystem and Polymodal Somatosensation in Speech Production

PURPOSE

The oral structures such as the tongue and lips have remarkable somatosensory capacities, but understanding the roles of somatosensation in speech production requires a more comprehensive knowledge of somatosensation in the speech production system in its entirety, including the respiratory, laryngeal, and supralaryngeal subsystems. This review was conducted to summarize the system-wide somatosensory information available for speech production.

METHOD

The search was conducted with PubMed/Medline and Google Scholar for articles published until November 2023. Numerous search terms were used in conducting the review, which covered the topics of psychophysics, basic and clinical behavioral research, neuroanatomy, and neuroscience.

RESULTS AND CONCLUSIONS

The current understanding of speech somatosensation rests primarily on the two pillars of psychophysics and neuroscience. The confluence of polymodal afferent streams supports the development, maintenance, and refinement of speech production. Receptors are both canonical and noncanonical, with the latter occurring especially in the muscles innervated by the facial nerve. Somatosensory representation in the cortex is disproportionately large and provides for sensory interactions. Speech somatosensory function is robust over the lifespan, with possible declines in advanced aging. The understanding of somatosensation in speech disorders is largely disconnected from research and theory on speech production. A speech somatoscape is proposed as the generalized, system-wide sensation of speech production, with implications for speech development, speech motor control, and speech disorders.

Development of a smartphone screening test for preclinical Alzheimer's disease and validation across the dementia continuum

BACKGROUND

Dementia prevalence is predicted to triple to 152 million globally by 2050. Alzheimer's disease (AD) constitutes 70% of cases. There is an urgent need to identify individuals with preclinical AD, a 10-20-year period of progressive brain pathology without noticeable cognitive symptoms, for targeted risk reduction. Current tests of AD pathology are either too invasive, specialised or expensive for population-level assessments. Cognitive tests are normal in preclinical AD. Emerging evidence demonstrates that movement analysis is sensitive to AD across the disease continuum, including preclinical AD. Our new smartphone test, TapTalk, combines analysis of hand and speech-like movements to detect AD risk. This study aims to [1] determine which combinations of hand-speech movement data most accurately predict preclinical AD [2], determine usability, reliability, and validity of TapTalk in cognitively asymptomatic older adults and [3], prospectively validate TapTalk in older adults who have cognitive symptoms against cognitive tests and clinical diagnoses of Mild Cognitive Impairment and AD dementia.

METHODS

Aim 1 will be addressed in a cross-sectional study of at least 500 cognitively asymptomatic older adults who will complete computerised tests comprising measures of hand motor control (finger tapping) and oro-motor control (syllabic diadochokinesis). So far, 1382 adults, mean (SD) age 66.20 (7.65) years, range 50-92 (72.07% female) have been recruited. Motor measures will be compared to a blood-based AD biomarker, phosphorylated tau 181 to develop an algorithm that classifies preclinical AD risk. Aim 2 comprises three sub-studies in cognitively asymptomatic adults: (i) a cross-sectional study of 30-40 adults to determine the validity of data collection from different types of smartphones, (ii) a prospective cohort study of 50-100 adults ≥ 50 years old to determine usability and test-retest reliability, and (iii) a prospective cohort study of ~1,000 adults ≥ 50 years old to validate against cognitive measures. Aim 3 will be addressed in a cross-sectional study of ~200 participants with cognitive symptoms to validate TapTalk against Montreal Cognitive Assessment and interdisciplinary consensus diagnosis.

DISCUSSION

This study will establish the precision of TapTalk to identify preclinical AD and estimate risk of cognitive decline. If accurate, this innovative smartphone app will enable low-cost, accessible screening of individuals for AD risk. This will have wide applications in public health initiatives and clinical trials.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT06114914, 29 October 2023. Retrospectively registered.

Speech timing and monosyllabic diadochokinesis measures in the assessment of amyotrophic lateral sclerosis in Canadian French

PURPOSE

The primary objective of this study was to determine if speech and pause measures obtained using a passage reading task and timing measures from a monosyllabic diadochokinesis (DDK) task differ across speakers of Canadian French diagnosed with amyotrophic lateral sclerosis (ALS) presenting with and without bulbar symptoms, and healthy controls. The secondary objective was to determine if these measures can reflect the severity of bulbar symptoms.

METHOD

A total of 29 Canadian French speakers with ALS (classified as bulbar symptomatic [n = 14] or pre-symptomatic [n = 15]) and 17 age-matched healthy controls completed a passage reading task and a monosyllabic DDK task (/pa/ and /ta/), for up to three follow-up visits. Measures of speaking rate, total duration, speech duration, and pause events were extracted from the passage reading recordings using a semi-automated speech and pause analysis procedure. Manual analysis of DDK recordings provided measures of DDK rate and variability.

RESULT

Group comparisons revealed significant differences (p = < .05) between the symptomatic group and the pre-symptomatic and control groups for all passage measures and DDK rates. Only the DDK rate in /ta/ differentiated the pre-symptomatic and control groups. Repeated measures correlations revealed moderate correlations (rrm = > 0.40; p = < 0.05) between passage measures of total duration, speaking rate, speech duration, and number of pauses, and ALSFRS-R total and bulbar scores, as well as between DDK rate and ALSFRS-R total score.

CONCLUSION

Speech and pause measures in passage and timing measures in monosyllabic DDK tasks might be suitable for monitoring bulbar functional symptoms in French speakers with ALS, but more work is required to identify which measures are sensitive to the earliest stages of the disease.

Pitch Variation Skills in Cantonese Speakers With Apraxia of Speech After Stroke: Preliminary Findings of Acoustic Analyses

PURPOSE

Literature on apraxia of speech (AOS) in Chinese speakers is sparse compared to the English literature. This study aims to examine the pitch variation skills of Cantonese adults with AOS poststroke in terms of perceptual tone accuracy, acoustic fundamental frequency (fo) changes, and repetition durations on items with different syllable structures, lexical status, and tone syllables in various positions in a sequencing context.

METHOD

Six Cantonese adults with AOS poststroke (AOS group), six adults without AOS poststroke (nAOS group), and six healthy controls (HC group) performed the tone sequencing task (TST), which was adapted from oral diadochokinetic tasks, with three different tone syllables. Tone accuracy, fo values across 10 time points, and acoustic repetition durations were compared within and between the groups.

RESULTS

The AOS group produced significantly lower tone accuracy and different fo changes on the three Cantonese tone syllables compared with the control groups and significantly longer repetition durations than the HC group. The AOS group showed more difficulty with the tone syllables with the consonant-vowel structure, while a priming effect was observed on the T2 (high-rising) syllables with lexical meanings. A unique lowering of fo in the final syllable of the trisyllabic items was observed only in the AOS group.

CONCLUSIONS

The AOS group showed degraded pitch variation skills. The effects of the three linguistic elements were discussed. Future investigations are called for to adapt the TST in other tonal languages to determine if degraded pitch variation skills are present in other tonal language speakers with AOS.

Oral diadochokinetic production in children with typical speech development and speech-sound disorders

BACKGROUND

AIMS: To investigate the developmental trajectory of the rate and perceptual assessment of oral diadochokinesis (DDK) in typically developing children compared with adults. Also to examine the characteristics of DDK productions in children with speech sound disorders (SSD) and the relationship between DDK production and percentage of consonants correct (PCC).

METHODS & PROCEDURES

Participants were 316 typically developing children and 90 children with SSD from 3 to 9 years old, as well as 20 adults with normal speech. The mono-, bi- and trisyllabic nonsense strings containing Korean tense consonants and the vowel [a] were used for DDK tasks. The number of iterations per s was measured as the DDK rate for each stimulus. The perceptual assessment of DDK productions was also performed for regularity, accuracy and rate.

OUTCOMES & RESULTS

The DDK rates increased throughout childhood, but the oldest children, 9-year-olds in the current study, did not achieve adult-like rates for all mono- and trisyllabic strings. Children with SSD also did not show significant differences from typically developing children when the DDK productions were analysed using only accurate tokens. The PCC of children with SSD showed higher correlations with regularity, accuracy and rate of perceptual ratings than the timed DDK rate.

CONCLUSIONS & IMPLICATIONS

This study highlighted the fact that the comprehensive evaluation of DDK productions may provide even more useful information about children's oral motor skills.

WHAT THIS PAPER ADDS

What is already known on the subject Rates of DDK reflect the motor skills of the articulatory systems independently of phonological skills; therefore, the tasks are widely used in the diagnostic evaluations of speech disorders in both children and adult populations. However, a substantial number of studies have questioned the validity and usefulness of DDK rates for evaluating speech abilities. Also, the literature suggested that the measure of DDK rate alone does not provide a clear and useful indication of children's oral motor skills. DDK tasks should be analysed in terms of accuracy and consistency as well as rate. What this paper adds to the existing knowledge The literature reporting normative DDK performance has mainly been based on English speakers. As different consonants have different temporal characteristics, the linguistic and segmental features of DDK tasks can impact the DDK rate. This study established a norm for DDK rate for Korean-speaking children and investigated the developmental trajectory of DDK performance in typically developing children compared with adults. This study suggested that the comprehensive evaluation of DDK productions may provide even more useful information about children's oral motor skills by examining the characteristics of DDK productions in children with SSD. What are the potential or actual clinical implications of this work? This study provided normative data of young Korean-speaking children aged 3-9 years. Normative data in children under 5 years of age are valuable given that the majority of children referred for speech difficulty assessments are between 3 and 5 years of age, but only a few studies have provided the normative data in young children. This study showed that many children could not complete DDK tasks correctly and provided additional support for the notion that other aspects of DDK performance, including accuracy and regularity, may yield more useful diagnostic indications than timed DDK rates alone.

A store-and-forward cloud-based telemonitoring system for automatic assessing dysarthria evolution in neurological diseases from video-recording analysis

BACKGROUND AND OBJECTIVES

Patients suffering from neurological diseases may develop dysarthria, a motor speech disorder affecting the execution of speech. Close and quantitative monitoring of dysarthria evolution is crucial for enabling clinicians to promptly implement patients' management strategies and maximizing effectiveness and efficiency of communication functions in term of restoring, compensating or adjusting. In the clinical assessment of orofacial structures and functions, at rest condition or during speech and non-speech movements, a qualitative evaluation is usually performed, throughout visual observation.

METHODS

To overcome limitations posed by qualitative assessments, this work presents a store-and-forward self-service telemonitoring system that integrates, within its cloud architecture, a convolutional neural network (CNN) for analyzing video recordings acquired by individuals with dysarthria. This architecture - called facial landmark Mask RCNN - aims at locating facial landmarks as a prior for assessing the orofacial functions related to speech and examining dysarthria evolution in neurological diseases.

RESULTS

When tested on the Toronto NeuroFace dataset, a publicly available annotated dataset of video recordings from patients with amyotrophic lateral sclerosis (ALS) and stroke, the proposed CNN achieved a normalized mean error equal to 1.79 on localizing the facial landmarks. We also tested our system in a real-life scenario on 11 bulbar-onset ALS subjects, obtaining promising outcomes in terms of facial landmark position estimation.

DISCUSSION AND CONCLUSIONS

This preliminary study represents a relevant step towards the use of remote tools to support clinicians in monitoring the evolution of dysarthria.

Exploring the acoustic and prosodic features of a lung-function-sensitive repeated-word speech articulation test

Introduction

Speech breathing is a term usually used to refer to the manner in which expired air and lung mechanics are utilized for the production of the airflow necessary for phonation. Neurologically, speech breathing overrides the normal rhythms of alveolar ventilation. Speech breathing is generated using the diaphragm, glottis, and tongue. The glottis is the opening between the vocal folds in the larynx; it is the primary valve between the lungs and the mouth, and by varying its degree of opening, the sound can be varied. The use of voice as an indicator of health has been widely reported. Chronic obstructive pulmonary disease (COPD) is the most common long-term respiratory disease. The main symptoms of COPD are increasing breathlessness, a persistent chesty cough with phlegm, frequent chest infections, and persistent wheezing. There is no cure for COPD, and it is one of the leading causes of death worldwide. The principal cause of COPD is tobacco smoking, and estimates indicate that COPD will become the third leading cause of death worldwide by 2030. The long-term aim of this research program is to understand how speech generation, breathing, and lung function are linked in people with chronic respiratory diseases such as COPD.

Methods

This pilot study was designed to test an articulatory speech task that uses a single word ("helicopter"), repeated multiple times, to challenge speech-generated breathing and breathlessness. Specifically, a single-word articulation task was used to challenge respiratory system endurance in people with healthy lungs by asking participants to rapidly repeat the word "helicopter" for three 20-s runs interspersed with two 20-s rest periods of silent relaxed breathing. Acoustic and prosodic features were then extracted from the audio recordings of each adult participant.

Results and discussion

The pause ratio increased from the first run to the third, representing an increasing demand for breath. These data show that the repeated articulation task challenges speech articulation in a quantifiable manner, which may prove useful in defining respiratory ill-health.

Wav2DDK: Analytical and Clinical Validation of an Automated Diadochokinetic Rate Estimation Algorithm on Remotely Collected Speech

PURPOSE

Oral diadochokinesis is a useful task in assessment of speech motor function in the context of neurological disease. Remote collection of speech tasks provides a convenient alternative to in-clinic visits, but scoring these assessments can be a laborious process for clinicians. This work describes Wav2DDK, an automated algorithm for estimating the diadochokinetic (DDK) rate on remotely collected audio from healthy participants and participants with amyotrophic lateral sclerosis (ALS).

METHOD

Wav2DDK was developed using a corpus of 970 DDK assessments from healthy and ALS speakers where ground truth DDK rates were provided manually by trained annotators. The clinical utility of the algorithm was demonstrated on a corpus of 7,919 assessments collected longitudinally from 26 healthy controls and 82 ALS speakers. Corpora were collected via the participants' own mobile device, and instructions for speech elicitation were provided via a mobile app. DDK rate was estimated by parsing the character transcript from a deep neural network transformer acoustic model trained on healthy and ALS speech.

RESULTS

Algorithm estimated DDK rates are highly accurate, achieving .98 correlation with manual annotation, and an average error of only 0.071 syllables per second. The rate exactly matched ground truth for 83% of files and was within 0.5 syllables per second for 95% of files. Estimated rates achieve a high test-retest reliability (r = .95) and show good correlation with the revised ALS functional rating scale speech subscore (r = .67).

CONCLUSION

We demonstrate a system for automated DDK estimation that increases efficiency of calculation beyond manual annotation. Thorough analytical and clinical validation demonstrates that the algorithm is not only highly accurate, but also provides a convenient, clinically relevant metric for tracking longitudinal decline in ALS, serving to promote participation and diversity of participants in clinical research.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.23787033.

Pareto-Optimized Non-Negative Matrix Factorization Approach to the Cleaning of Alaryngeal Speech Signals

The problem of cleaning impaired speech is crucial for various applications such as speech recognition, telecommunication, and assistive technologies. In this paper, we propose a novel approach that combines Pareto-optimized deep learning with non-negative matrix factorization (NMF) to effectively reduce noise in impaired speech signals while preserving the quality of the desired speech. Our method begins by calculating the spectrogram of a noisy voice clip and extracting frequency statistics. A threshold is then determined based on the desired noise sensitivity, and a noise-to-signal mask is computed. This mask is smoothed to avoid abrupt transitions in noise levels, and the modified spectrogram is obtained by applying the smoothed mask to the signal spectrogram. We then employ a Pareto-optimized NMF to decompose the modified spectrogram into basis functions and corresponding weights, which are used to reconstruct the clean speech spectrogram. The final noise-reduced waveform is obtained by inverting the clean speech spectrogram. Our proposed method achieves a balance between various objectives, such as noise suppression, speech quality preservation, and computational efficiency, by leveraging Pareto optimization in the deep learning model. The experimental results demonstrate the effectiveness of our approach in cleaning alaryngeal speech signals, making it a promising solution for various real-world applications.

Oral Diadochokinetic Performance on Perceptual and Acoustic Measures for Typically Developing Cantonese-Speaking Preschool Children

PURPOSE

This study investigated native Cantonese-speaking preschool children's diadochokinetic performance, including rate, accuracy, and regularity. The second aim of this study was to examine whether language-specific patterns exist by comparing diadochokinetic rates with the average DKK rate for native English speakers.

METHOD

Sixty-four typically developing preschool children who were native Cantonese speakers participated. The diadochokinetic task administered to the children involved repetitions of monosyllabic, disyllabic, and trisyllabic words and nonsense words. The maximum performance of the children was compared by diadochokinetic rate (number of syllables per second), accuracy (percentage of matched production), and regularity (pairwise variability indexes, known as PVIs).

RESULTS

Monosyllabic units were produced faster, more accurately, and more regularly than multisyllabic units. Word repetition showed higher accuracy and generally lower regularity than nonsense words but similar rates. Older children were faster and more regular (higher raw PVI of initial consonants) than younger children, but younger children performed as accurately as them. When compared with data from English speakers, the diadochokinetic rates of Cantonese children were generally lower.

CONCLUSIONS

Developmental progression was evident in terms of rate and regularity. The distinctive accuracy and regularity patterns between word and nonsense word repetition suggest a clinical value for both stimulus types. Language typology plays a role in diadochokinetic rate, supporting the use of language-specific reference data in practice. The typical diadochokinetic profile obtained in this study could serve as a clinical reference for speech motor assessments.

Oromotor Nonverbal Performance and Speech Motor Control: Theory and Review of Empirical Evidence

This position paper offers a perspective on the long-standing debate concerning the role of oromotor, nonverbal gestures in understanding typical and disordered speech motor control secondary to neurological disease. Oromotor nonverbal tasks are employed routinely in clinical and research settings, but a coherent rationale for their use is needed. The use of oromotor nonverbal performance to diagnose disease or dysarthria type, versus specific aspects of speech production deficits that contribute to loss of speech intelligibility, is argued to be an important part of the debate. Framing these issues are two models of speech motor control, the Integrative Model (IM) and Task-Dependent Model (TDM), which yield contrasting predictions of the relationship between oromotor nonverbal performance and speech motor control. Theoretical and empirical literature on task specificity in limb, hand, and eye motor control is reviewed to demonstrate its relevance to speech motor control. The IM rejects task specificity in speech motor control, whereas the TDM is defined by it. The theoretical claim of the IM proponents that the TDM requires a special, dedicated neural mechanism for speech production is rejected. Based on theoretical and empirical information, the utility of oromotor nonverbal tasks as a window into speech motor control is questionable.

Acoustic Analysis and Neuroimaging Correlates of Diadochokinetic Rates in Mild-Moderate Primary Progressive Apraxia of Speech

Speech rate can be judged clinically using diadochokinetic (DDK) tasks, such as alternating motion rates (AMR) and sequential motion rates (SMR). We evaluated whether acoustic AMR/SMR speech rates would differentiate primary progressive apraxia of speech (PPAOS) from healthy controls, and determined how DDK rates relate to phonetic and prosodic speech characteristics and brain metabolism on FDG-PET. Rate was calculated for each of three AMRs (repetitions of 'puh', 'tuh', and 'kuh') and for SMRs (repetitions of 'puhtuhkuh') for 27 PPAOS patients and 52 controls who underwent FDG-PET. PPAOS patients were slower than controls on all DDK tasks. All DDK rates correlated with apraxia of speech severity, with strongest associations with prosodic speech features. Slower DDK rates were associated with hypometabolism in the right cerebellar dentate and left supplementary motor area. Performance on AMR rate, not just SMR rate, may be impaired in mild PPAOS, but sensitivity and specificity require further study.

What Do Differences between Alternating and Sequential Diadochokinetic Tasks Tell Us about the Development of Oromotor Skills? An Insight from Childhood to Adulthood

Oral diadochokinetic (DDK) tasks are common research and clinical tools used to test oromotor skills across different age groups. They include alternating motion rate (AMR) and sequential motion rate (SMR) tasks. AMR tasks involve repeating a single syllable, whereas SMR tasks involve repeating varying syllables. DDK performance is mostly discussed regarding the increasing rates of AMR and SMR tasks from childhood to adulthood, although less attention is given to the performance differences between SMR and AMR tasks across age groups. Here, AMR and SMR syllabic rates were contrasted in three populations: 7-9-year-old children, 14-16-year-old adolescents and 20-30-year-old adults. The results revealed similar syllabic rates for the two DDK tasks in children, whereas adolescents and adults achieved faster SMR rates. Acoustic analyses showed similarities in prosodic features between AMR and SMR sequences and in anticipatory coarticulation in the SMR sequences in all age groups. However, a lower degree of coarticulation was observed in children relative to adults. Adolescents, on the contrary, showed an adult-like pattern. These findings suggest that SMR tasks may be more sensitive to age-related changes in oromotor skills than AMR tasks and that greater gestural overlap across varying syllables may be a factor in achieving higher rates in SMR tasks.

Speech and Nonspeech Parameters in the Clinical Assessment of Dysarthria: A Dimensional Analysis

Nonspeech (or paraspeech) parameters are widely used in clinical assessment of speech impairment in persons with dysarthria (PWD). Virtually every standard clinical instrument used in dysarthria diagnostics includes nonspeech parameters, often in considerable numbers. While theoretical considerations have challenged the validity of these measures as markers of speech impairment, only a few studies have directly examined their relationship to speech parameters on a broader scale. This study was designed to investigate how nonspeech parameters commonly used in clinical dysarthria assessment relate to speech characteristics of dysarthria in individuals with movement disorders. Maximum syllable repetition rates, accuracies, and rates of isolated and repetitive nonspeech oral-facial movements and maximum phonation times were compared with auditory-perceptual and acoustic speech parameters. Overall, 23 diagnostic parameters were assessed in a sample of 130 patients with movement disorders of six etiologies. Each variable was standardized for its distribution and for age and sex effects in 130 neurotypical speakers. Exploratory Graph Analysis (EGA) and Confirmatory Factor Analysis (CFA) were used to examine the factor structure underlying the diagnostic parameters. In the first analysis, we tested the hypothesis that nonspeech parameters combine with speech parameters within diagnostic dimensions representing domain-general motor control principles. In a second analysis, we tested the more specific hypotheses that diagnostic parameters split along effector (lip vs. tongue) or functional (speed vs. accuracy) rather than task boundaries. Our findings contradict the view that nonspeech parameters currently used in dysarthria diagnostics are congruent with diagnostic measures of speech characteristics in PWD.

Automated Analysis of Phonoarticulatory Diadochokinesis in Tamil Speakers

OBJECTIVES

Diadochokinetic rate (DDK) quantifies the laryngeal and oral muscle coordination, but there are insufficient baseline evidence exist, that limits the effectiveness of computerized DDK evaluation in assessing motor speech control. In the end, this study will give normative data on age and gender effects on both oral and laryngeal DDK in Tamil speakers.

STUDY DESIGN

Cross sectional Study.

METHOD

A total of 150 participants in the age range of 17-25;11 years were divided into three groups- Group I (17-19;11 years), Group II (20-22;11 years) and Group III (23-25;11 years) with equal number of male and female. The participants were asked to produce /pʌ/, /tʌ/, /kʌ/, /pʌtʌkʌ/, /a/& /i/ for 5 seconds in Motor Speech Profile (MSP), at Computerized Speech Lab (CSL). The parameters such as Average DDK period (DDKavp), average DDK rate (DDKavr), Standard deviation(SD) of DDK period (DDKsdp), Coefficient of Variation of DDK period (DDKcdp), Perturbations of DDK period (DDKJit) and Coefficient of variation of the DDK peak intensity (DDKcvi) were selected for analysis.

RESULT

The effect of age was noted for Laryngeal DDK, the DDKavr of /a/ (P = 0.008) and /i/ (P = 0.04) and DDKcdp for /a/ (P = 0.01), the mean values of those parameters are higher for the individuals within the age of 23-25;11 years but no difference was observed across the age for Oral DDK. The effect of gender was noted for Laryngeal DDK, DDKsdp (P = 0.007) and DDKJit (P = 0.04) for /i/, the mean values are higher for females. For Oral DDK, DDKJit (P = 0.006) for /kʌ/ the mean values are higher for females.

CONCLUSION

The normative data has been established for the Tamil speakers. Age specific normative should be used during the DDK evaluation of speech disorders in MSP, CSL.

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.

Articulatory Performance in Dysarthria: Using a Data-Driven Approach to Estimate Articulatory Demands and Deficits

This study pursued two goals: (1) to establish range of motion (ROM) demand tiers (i.e., low, moderate, high) specific to the jaw (J), lower lip (LL), posterior tongue (PT), and anterior tongue (AT) for multisyllabic words based on the articulatory performance of neurotypical talkers and (2) to identify demand- and disease-specific articulatory performance characteristics in talkers with amyotrophic lateral sclerosis (ALS) and Parkinson's disease (PD). J, LL, PT, and AT movements of 12 talkers with ALS, 12 talkers with PD, and 12 controls were recorded using electromagnetic articulography. Vertical ROM, average speed, and movement duration were measured. Results showed that in talkers with PD, J and LL ROM were already significantly reduced at the lowest tier whereas PT and AT ROM were only significantly reduced at moderate and high tiers. In talkers with ALS, J ROM was significantly reduced at the moderate tier whereas LL, PT, and AT ROM were only significantly reduced at the highest tier. In both clinical groups, significantly reduced J and LL speeds could already be observed at the lowest tier whereas significantly reduced AT speeds could only be observed at the highest tier. PT speeds were already significantly reduced at the lowest tier in the ALS group but not until the moderate tier in the PD group. Finally, movement duration, but not ROM or speed performance, differentiated between ALS and PD even at the lowest tier. Results suggest that articulatory deficits vary with stimuli-specific motor demands across articulators and clinical groups.

Association between oral function and physical pre-frailty in community-dwelling older people: a cross-sectional study

BACKGROUND

Few studies have examined the relationship between oral functions and the physical pre-frailty status, classified using physical function tests. This cross-sectional study aimed to clarify this association among community-dwelling older people from the Itoshima Frail Study in Itoshima Fukuoka Prefecture.

METHODS

Of the 1,555 individuals invited to join the study, 381 (188 males and 193 females) enrolled. Their physical pre-frailty was assessed with a classification system consisting of two physical indicators (fatigue and unintentional weight loss, determined with a questionnaire), two functional components (declined walking speed and muscle weakness, determined using a body function measuring instrument), and declined physical activity (examined using a triaxial accelerometer). Subsequently, the individuals were classified into three groups: robust, pre-frailty, and frailty. Along with the number of teeth remaining, oral functions, such as masticatory performance, tongue pressure strength, and oral diadochokinesis (ODK), were examined. Data regarding social activity and exercise habits were collected, and the individuals' body compositions were measured. Odds ratios (ORs) and 95% confidence intervals (CIs) for the physical pre-frailty were calculated using logistic regression models.

RESULTS

In this study, 126 (33%) participants presented with physical pre-frailty. The participants in the robust group were younger, had stronger maximum handgrip strength, and walked faster than those in the physical pre-frailty group (p < 0.001). The robust group presented with better oral functions (masticatory performance, p = 0.015; oral ODK /ta/, p = 0.004). The physical pre-frailty status was significantly associated with age (OR, 1.111; 95% CI, 1.048-1.178; p < 0.001), masticatory performance (OR, 0.819; 95% CI, 0.680-0.986; p = 0.035), low ODK/ta/ (OR, 1.864; 95% CI, 1.069-3.250; p = 0.028), and low social activity (OR, 2.273; 95% CI, 1.308-3.951; p = 0.004).

CONCLUSION

This study indicated that older people with higher age, lower anterior tongue movement, lower masticatory performance, and lower social activity are positively associated with physical pre-frailty.

Perceptual Classification of Motor Speech Disorders: The Role of Severity, Speech Task, and Listener's Expertise

PURPOSE

The clinical diagnosis of motor speech disorders (MSDs) is mainly based on perceptual approaches. However, studies on perceptual classification of MSDs often indicate low classification accuracy. The aim of this study was to determine in a forced-choice dichotomous decision-making task (a) how accuracy of speech-language pathologists (SLPs) in perceptually classifying apraxia of speech (AoS) and dysarthria is impacted by speech task, severity of MSD, and listener's expertise and (b) which perceptual features they use to classify.

METHOD

Speech samples from 29 neurotypical speakers, 14 with hypokinetic dysarthria associated with Parkinson's disease (HD), 10 with poststroke AoS, and six with mixed dysarthria associated with amyotrophic lateral sclerosis (MD-FlSp [combining flaccid and spastic dysarthria]), were classified by 20 expert SLPs and 20 student SLPs. Speech samples were elicited in spontaneous speech, text reading, oral diadochokinetic (DDK) tasks, and a sample concatenating text reading and DDK. For each recorded speech sample, SLPs answered three dichotomic questions following a diagnostic approach, (a) neurotypical versus pathological speaker, (b) AoS versus dysarthria, and (c) MD-FlSp versus HD, and a multiple-choice question on the features their decision was based on.

RESULTS

Overall classification accuracy was 72% with good interrater reliability, varying with SLP expertise, speech task, and MSD severity. Correct classification of speech samples was higher for speakers with dysarthria than for AoS and higher for HD than for MD-FlSp. Samples elicited with continuous speech reached the best classification rates. An average number of three perceptual features were used for correct classifications, and their type and combination differed between the three MSDs.

CONCLUSIONS

The auditory-perceptual classification of MSDs in a diagnostic approach reaches substantial performance only in expert SLPs with continuous speech samples, albeit with lower accuracy for AoS. Specific training associated with objective classification tools seems necessary to improve recognition of neurotypical speech and distinction between AoS and dysarthria.

Clinical Linguistics: Analysis of Mapping Knowledge Domains in Past, Present and Future

Across the world, many infants, children, adults, and elderly people are reported with many types of disorders and disabilities that damage, delay, or impede typical language development and/or use. Speech-language pathologists and other relevant clinicians are responsible for diagnosing, assessing, and rehabilitating these conditions. In nearly all types of disorders or disabilities that affect language, clinical linguistics plays a significant role in their study, diagnosis, and evaluation. This study provides a thorough analysis of the field of clinical linguistics. Data from Scopus, WOS, and Lens were used between 1981 and 2022. The documents included in the analysis were 1685, 1628, and 2677 articles published between 1981 and 2022 in clinical linguistics in Scopus, WOS, and Lens, respectively. For the purpose of assessing the development and impacts of the field of clinical linguistics, we used eight bibliometric and eight scientometric indicators. As part of the study, the results summarized the top contributors to clinical linguistics in terms of production size by year, country, university/research centre, journal, publisher, and author. The impact of the examined evidence on clinical linguistics was visualized and tabulated in the form of visual networks, citation counts, burst, cooccurrence, centrality, and sigma factors that are helpful in identifying the main influencers in clinical linguistics. A few examples of clinical linguistics patterns that are being explored extensively by researchers include cleft palate speech with model theories, visual feedback, motor speech disorders with instrumental analysis, acoustic analysis to understand conversational breakdown, nonlinear phonological theory, aphasic conversation in atypical interaction, and diagnostic markers in functional segments. There are also phonological disorders, William Syndrome, and the use of ultrasound, which may be considered potential clusters of clinical linguistics. A key contribution of this paper is highlighting the importance of clinical linguistics as well as its integration with linguistics, speech-language pathology, neurolinguistics, psycholinguistics, neuroscience, cognitive sciences, psychology, and psychometrics.

Tone and vowel disruptions in Mandarin aphasia and apraxia of speech

In this study, we investigated the lexical tones and vowels produced by ten speakers diagnosed with aphasia and coexisting apraxia of speech (A-AOS) and ten healthy participants, to compare their tone and vowel disruptions. We first judged the productions of both A-AOS and healthy participants and classified them into three categories, i.e. those by healthy speakers and rated as correct, those by A-AOS participants and rated as correct, and those by A-AOS participants and rated as incorrect. We then compared the perceptual results for the three groups based on their respective acoustic correlates to reveal the relations among different accuracy groups. Results showed that the numbers of tone and vowel disruptions by A-AOS speakers occurred on a comparable scale. In perception, approximately equal numbers of tones and vowels produced by A-AOS participants were identified as correct; however, acoustic parameters showed that, unlike vowels, the patients' tones categorised as correct by native Mandarin listeners differed considerably from those of the healthy speakers, suggesting that for Mandarin A-AOS patients, tones were in fact more disrupted than vowels in acoustic terms. Native Mandarin listeners seemed to be more tolerant of less well-targeted tones than less-well targeted vowels. The clinical implication is that tonal and segmental practice should be incorporated for Mandarin A-AOS patients to enhance their overall motor speech control.