Effect of Parkinson's disease on the production of structured and unstructured speaking tasks: respiratory physiologic and linguistic considerations

Vocal and tongue exercise in early to mid-stage Parkinson disease using the Pink1-/- rat

Vocal and swallowing deficits are common in Parkinson disease (PD). Because these impairments are resistant to dopamine replacement therapies, vocal and lingual exercise are the primary treatment, but not all individuals respond to exercise and neural mechanisms of treatment response are unclear. To explore putative mechanisms, we used the progressive Pink1-/- rat model of early to mid-stage PD and employed vocal and lingual exercises at 6- and 10-months of age in male Pink1-/- and wild type (WT) rats. We hypothesized that vocal and lingual exercise would improve vocal and tongue use dynamics and increase serotonin (5HT) immunoreactivity in related brainstem nuclei. Rats were tested at baseline and after 8 weeks of exercise or sham exercise. At early-stage PD (6 months), vocal exercise resulted in increased call complexity, but did not change intensity, while at mid-stage (10 months), vocal exercise no longer influenced vocalization complexity. Lingual exercise increased tongue force generation and reduced relative optical density of 5HT in the hypoglossal nucleus at both time points. The effects of vocal and lingual exercise at these time points are less robust than in prodromal stages observed in previous work, suggesting that early exercise interventions may yield greater benefit. Future work targeting optimization of exercise at later time points may facilitate clinical translation.

Sex Differences in the Speech of Persons With and Without Parkinson's Disease

BACKGROUND

Sex differences are apparent in the prevalence and the clinical presentation of Parkinson's disease (PD), but their effects on speech have been less studied.

METHOD

Speech acoustics of persons with (34 females and 34 males) and without (age- and sex-matched) PD were examined, assessing the effects of PD diagnosis and sex on ratings of dysarthria severity and acoustic measures of phonation (fundamental frequency standard deviation, smoothed cepstral peak prominence), speech rate (net syllables per second, percent pause ratio), and articulation (articulatory-acoustic vowel space, release burst precision).

RESULTS

Most measures were affected by PD (dysarthria severity, fundamental frequency standard deviation) and sex (smoothed cepstral peak prominence, net syllables per second, percent pause ratio, articulatory-acoustic vowel space), but without interactions between them. Release burst precision was differentially affected by sex in PD. Relative to those without PD, persons with PD produced fewer plosives with a single burst: females more frequently produced multiple bursts, whereas males more frequently produced no burst at all.

CONCLUSIONS

Most metrics did not indicate that speech production is differentially affected by sex in PD. Sex was, however, associated with disparate effects on release burst precision in PD, which deserves further study.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.24388666.

Thyroarytenoid Oxidative Metabolism and Synaptic Signaling Dysregulation in the Female Pink1-/- Rat

OBJECTIVES AND HYPOTHESIS

Vocal dysfunction, including hypophonia, in Parkinson disease (PD) manifests in the prodromal period and significantly impacts an individual's quality of life. Data from human studies suggest that pathology leading to vocal deficits may be structurally related to the larynx and its function. The Pink1-/- rat is a translational model used to study pathogenesis in the context of early-stage mitochondrial dysfunction. The primary objective of this work was to identify differentially expressed genes in the thyroarytenoid muscle and examine the dysregulated biological pathways in the female rat.

METHODS

RNA sequencing was used to determine thyroarytenoid (TA) muscle gene expression in adult female Pink1-/- rats compared with controls. A bioinformatic approach and the ENRICHR gene analysis tool were used to compare the sequencing dataset with biological pathways and processes, disease relationships, and drug-repurposing compounds. Weighted Gene Co-expression Network Analysis was used to construct biological network modules. The data were compared with a previously published dataset in male rats.

RESULTS

Significant upregulated pathways in female Pink1-/- rats included fatty acid oxidation and muscle contraction, synaptic transmission, and neuromuscular processes. Downregulated pathways included anterograde transsynaptic signaling, chemical synaptic transmission, and ion release. Several drug treatment options including cetuximab, fluoxetine, and resveratrol are hypothesized to reverse observed genetic dysregulation.

CONCLUSIONS

Data presented here are useful for identifying biological pathways that may underlie the mechanisms of peripheral dysfunction including neuromuscular synaptic transmission to the TA muscle. These experimental biomarkers have the potential to be targeted as sites for improving the treatment for hypophonia in early-stage PD.

LEVEL OF EVIDENCE

NA Laryngoscope, 133:3412-3421, 2023.

Articulation Rate, Pauses, and Disfluencies in Professional Fighters: Potential Speech Biomarkers for Repetitive Head Injury

OBJECTIVE

As part of a larger study dedicated to identifying speech and language biomarkers of neurological decline associated with repetitive head injury (RHI) in professional boxers and mixed martial artists (MMAs), we examined articulation rate, pausing, and disfluency in passages read aloud by participants in the Professional Athletes Brain Health Study.

SETTING

A large outpatient medical center specializing in neurological care.

PARTICIPANTS, DESIGN, AND MAIN MEASURES

Passages read aloud by 60 boxers, 40 MMAs, and 55 controls were acoustically analyzed to determine articulation rate (the number of syllables produced per second), number and duration of pauses, and number and duration of disfluencies in this observational study.

RESULTS

Both boxers and MMAs differed from controls in articulation rate, producing syllables at a slower rate than controls by nearly half a syllable per second on average. Boxers produced significantly more pauses and disfluencies in passages read aloud than MMAs and controls.

CONCLUSIONS

Slower articulation rate in both boxers and MMA fighters compared with individuals with no history of RHI and the increased occurrence of pauses and disfluencies in the speech of boxers suggest changes in speech motor behavior that may relate to RHI. These speech characteristics can be measured in everyday speaking conditions and by automatic recognition systems, so they have the potential to serve as effective, noninvasive clinical indicators for RHI-associated neurological decline.

Intergenerational choral singing to improve communication outcomes in Parkinson's disease: Development of a theoretical framework and an integrated measurement tool

Purpose: This study presented an initial step towards developing the evidence base for intergenerational choral singing as a communication-focussed rehabilitative approach for Parkinson's disease (PD).Method: A theoretical framework was established to conceptualise the rehabilitative effect of intergenerational choral singing on four domains of communication impairments - motor drive, timing mechanism, sensorimotor integration, higher-level cognitive and affective functions - as well as activity/participation, and quality of life. A computer-assisted multidimensional acoustic analysis was developed to objectively assess the targeted domains of communication impairments. Voice Handicap Index and the World Health Organization's Quality of Life assessment-abbreviated version were used to obtain patient-reported outcomes at the activity/participation and quality of life levels. As a proof of concept, a single subject with PD was recruited to participate in 9 weekly 1-h intergenerational choir rehearsals. The subject was assessed before, 1 week post, and 8 weeks post-choir.Result: Notable trends of improvement were observed in multiple domains of communication impairments at 1 week post-choir. Some improvements were maintained at 8 weeks post-choir. Patient-reported outcomes exhibited limited pre-post changes.Conclusion: This study provided the theoretical groundwork and an empirical measurement tool for future validation of intergenerational choral singing as a novel rehabilitation for PD.

Global Acoustic Speech Temporal Characteristics for Mandarin Speakers With Parkinson's Disease During Syllable Repetition and Passage Reading

PURPOSE

Previous research has revealed considerable variation in speech rates among English speakers with Parkinson's disease (PD) with slower, faster, or similar rates than controls. The purpose of this study was to characterize speech rates of Mandarin speakers with PD and the corresponding articulation and pause characteristics explaining the speech rates to enhance rate control therapies.

METHOD

Eighteen Mandarin speakers with PD and 18 controls produced syllable repetitions and passage reading using their typical speech style. Speech rates, articulation rates, mean pause durations (≥ 10 ms), and the number of pauses with duration between 10 ms and 300 ms and greater than 300 ms were measured and compared between groups and tasks as well as across the initial, middle, and final periods of the passage. Two-way, mixed-model analyses of variance were employed for data analysis.

RESULTS

Compared to controls, individuals with PD spoke with similar speech rates and faster articulation rates during passage reading, whereas during syllable repetitions, they produced slower speech rates and comparable articulation rates. The slower syllable repetitions produced by speakers with PD may be explained by longer pauses and more perceptual pauses, whereas faster articulation rates may explain the trend of faster speech rates during reading. Speech and articulation rates accelerated for both groups during passage reading.

CONCLUSIONS

Speech rates of Mandarin speakers with PD were characterized by faster articulation, longer pauses, and more perceptual pauses for passage reading. A descriptive model of speech rate suggested that speakers with PD and dysarthria in this study would benefit from rate reduction therapy decreasing articulation rate.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.23982282.

Reliability of a Linguistic Segmentation Procedure Specified by Systemic Functional Linguistics to Examine Extemporaneous Speech

PURPOSE

Extemporaneous speech tasks provide an ecologically valid sample to examine speech acoustics, but differing methodologies exist in the literature for segmentation. Therefore, the purpose of this study was to examine the utility and reliability of a segmentation approach for extemporaneous speech specified by systemic functional linguistics (SFL) and its potential research and clinical applications.

METHOD

Ten speakers without communication disorders served as participants in this study, and they responded to self-selected extemporaneous speaking prompts. Two expert analysts and one clinician analyst utilized a segmentation procedure specified by SFL to segment the extemporaneous speech samples into clauses and clause complexes. Intra- and interrater reliability were calculated for each analyst and pair of analysts. Acoustic measures of duration, speech rate, and intercomplex pause durations were calculated for each clause complex.

RESULTS

Analyses for both intra- and interrater reliability revealed high percent agreement that was significantly greater than chance for expert and clinician analysts and between each pair of analysts (p < .001). Acoustic analyses revealed expected variation in number and duration of spoken syllables of clause complexes between and within speakers.

CONCLUSIONS

The segmentation approach for extemporaneous speech specified by SFL is a reliable method for trained analysts that is informed by lexico-grammar and allows for acoustic measurement of speech production. It is also a reliable method for clinician analysts for speakers without communication disorders, and future work will investigate its utility for speakers with motor speech disorders.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.22357138.

The Effects of Speech Task on Lexical Stress in Parkinson's Disease

PURPOSE

Hypokinetic dysarthria associated with Parkinson's disease (PD) is characterized by dysprosody, yet the literature is mixed with respect to how dysprosody affects the ability to mark lexical stress, possibly due to differences in speech tasks used to assess lexical stress. The purpose of this study was to compare how people with and without PD modulate acoustic dimensions of lexical stress-fundamental frequency, intensity, and duration-to mark lexical stress across three different speech tasks.

METHOD

Twelve individuals with mild-to-moderate idiopathic PD and 12 age- and sex-matched older adult controls completed three speech tasks: picture description, word production in isolation, and word production in lists. Outcome measures were the fundamental frequency, intensity, and duration of the vocalic segments of two trochees (initial stress) and two iambs (final stress) spoken in all three tasks.

RESULTS

There were very few group differences. Both groups marked trochees by modulating intensity and fundamental frequency and iambs by modulating duration. Task had a significant impact on the stress patterns used by both groups. Stress patterns were most differentiated in words produced in isolation and least differentiated in lists of words.

CONCLUSIONS

People with PD did not demonstrate impairments in the production of lexical stress, suggesting that dysprosody associated with PD does not impact all types of prosody in the same way. However, there were reduced distinctions in stress marking that were more apparent in trochees than iambs. In addition, the task used to assess prosody has a significant effect on all acoustic measures. Future research should focus on the use of connected speech tasks to obtain more generalizable measures of prosody in PD.

Singing and Speaking Ability in Parkinson's Disease and Spinocerebellar Ataxia

PURPOSE

This study examined spontaneous, spoken-to-a-model, and two sung modes in speakers with Parkinson's disease (PD), speakers with cerebellar disease (CD), and healthy controls. Vocal performance was measured by intelligibility scores and listeners' perceptual ratings.

METHOD

Participants included speakers with hypokinetic dysarthria secondary to PD, those with ataxic dysarthria secondary to CD, and healthy speakers. Participants produced utterances in four vocal modes: spontaneous speech, spoken-to-a-model, sung-to-a-model, and spontaneous singing. For spoken-to-a-model and sung-to-a-model modes, written material was provided the model. For spontaneous singing, participants sang songs that they endorsed as familiar.

DEPENDENT VARIABLES

In Experiment I, listeners orthographically transcribed the audio samples of the first three vocal modes. In Experiment IIa, raters evaluated the accuracy of the pitch and rhythm of the spontaneous singing of familiar songs. Finally, familiar songs and sung-to-a-model utterances were rated on a competency scale by a second group of raters (Experiment IIb).

RESULTS

Results showed increases in intelligibility during the spoken-to-a-model mode compared with the spontaneous mode in both PD and CD groups. Singing enhanced the vocal output of speakers with PD more than in speakers with CD, as measured by percent intelligibility. PD participants' pitch and rhythm accuracy and competency in singing familiar songs was rated more favorably than those produced by CD participants.

CONCLUSIONS

The findings reveal a vocal task effect for spoken utterances in both groups. Sung exemplars, more impaired in CD, suggest a significant involvement of the cerebellum in singing.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.21809544.

Pausing before verb production is associated with mild cognitive impairment in Parkinson's disease

Background

Cognitive dysfunction and communication impairment are common and disabling symptoms in Parkinson's Disease (PD). Action verb deficits occur in PD, but it remains unclear if these impairments are related to motor system dysfunction and/or cognitive decline. The objective of our study was to evaluate relative contributions of cognitive and motor dysfunction to action verb production in naturalistic speech of patients with PD. We proposed that pausing before action-related language is associated with cognitive dysfunction and may serve as a marker of mild cognitive impairment in PD.

Method

Participants with PD (n = 92) were asked to describe the Cookie Theft picture. Speech files were transcribed, segmented into utterances, and verbs classified as action or non-action (auxiliary). We measured silent pauses before verbs and before utterances containing verbs of different classes. Cognitive assessment included Montreal Cognitive Assessment (MoCA) and neuropsychological tests to categorize PD participants as normal cognition (PD-NC) or mild cognitive impairment (PD-MCI) based on Movement Disorders Society (MDS) Task Force Tier II criteria. Motor symptoms were assessed using MDS-UPDRS. We performed Wilcoxon rank sum tests to identify differences in pausing between PD-NC and PD-MCI. Logistic regression models using PD-MCI as dependent variables were used to evaluate the association between pause variables and cognitive status.

Results

Participants with PD-MCI demonstrated more pausing before and within utterances compared to PD-NC, and the duration of these pauses were correlated with MoCA but not motor severity (MDS-UPDRS). Logistic regression models demonstrated that pauses before action utterances were associated with PD-MCI status, whereas pauses before non-action utterances were not significantly associated with cognitive diagnosis.

Conclusion

We characterized pausing patterns in spontaneous speech in PD-MCI, including analysis of pause location with respect to verb class. We identified associations between cognitive status and pausing before utterances containing action verbs. Evaluation of verb-related pauses may be developed into a potentially powerful speech marker tool to detect early cognitive decline in PD and better understand linguistic dysfunction in PD.

A Descriptive Study of Speech Breathing in Children With Cerebral Palsy During Two Types of Connected Speech Tasks

PURPOSE

This study examined speech breathing during two connected speech tasks in children with cerebral palsy (CP) and typically developing (TD) peers. Understanding how the respiratory system supports speech production during various speech tasks can help researchers construct appropriate models of speech production and clinicians remediate speech disorders effectively.

METHOD

Four children with CP and four age- and sex-matched TD peers completed two speech tasks, reading and extemporaneous speech. Respiratory kinematic and acoustic data were collected. Dependent variables included utterance length, speech rate, sound pressure level, and lung volume variables.

RESULTS

Based on descriptive results, children with CP and speech motor involvement demonstrated reduced utterance length and speech rate, equivalent intensity levels, and changes in lung volume variables indicative of respiratory physiological impairment as compared to their TD peers. However, children with CP and no speech motor involvement exhibited speech production and speech breathing variables in the more typical range. In relation to task effects, the majority of children (CP and TD) produced shorter utterances, slower speech rates, equivalent intensity levels, higher lung volume initiation, termination, excursion, higher percent vital capacity per syllable, and longer inspiratory duration during extemporaneous speech as compared to reading.

CONCLUSIONS

Two major themes emerged from the data: (a) Children with CP, particularly those with concomitant speech motor involvement, demonstrate different speech production and speech breathing patterns than their TD peers. (b) Speech task impacts speech production and speech breathing variables in both children with CP and their TD peers, but the extemporaneous speech task did not seem to exaggerate group differences.

Task-based profiles of language impairment and their relationship to cognitive dysfunction in Parkinson's disease

Objective

Parkinson’s Disease (PD) is associated with both motor and non-motor problems, such as cognitive impairment. Particular focus in this area has been on the relationship between language impairment and decline in other cognitive functions, with the literature currently inconclusive on how the nature and degree of language impairment relate to cognition or other measures of disease severity. In addition, little information is available on how language problems identified in experimental task set-ups relate to competency in self-generated language paradigms such as picture description, monologues or conversations. This study aimed to inform clinical management of language impairment in PD by exploring (1) language performance across a range of experimental as well as self-generated language tasks, (2) how the relationship between these two aspects might be affected by the nature of the cognitive and language assessment; and (3) to what degree performance can be predicted across the language tasks.

Methods

22 non-demented people with PD (PwPD) and 22 healthy control participants performed a range of cognitive and language tasks. Cognitive tasks included a screening assessment in addition to tests for set shifting, short term memory, attention, as well as letter and category fluency. Language was investigated in highly controlled grammar tasks as well as a Sentence Generation and a Narrative.

Results

The study highlighted impaired ability in set-shifting and letter fluency in the executive function tasks, and a higher rate of grammatical and lexical errors across all language tasks in the PD group. The performance in the grammar task was linked to set shifting ability, but error rates in Sentence Generation and Narrative were independent of this. There was no relevant relationship between performances across the three language tasks.

Conclusions

Our results suggest that there is a link between executive function and language performance, but that this is task dependent in non-demented PwPD. This has implications for the management of language impairment in PD, both for assessment and for designing effective interventions.

Respiratory Responses to Two Voice Interventions for Parkinson's Disease

PURPOSE

The purpose of this study was to examine the respiratory strategies used by persons with Parkinson's disease (PD) to support louder speech in response to two voice interventions. Contrasting interventions were selected to investigate the role of internal and external cue strategies on treatment outcomes. LSVT LOUD, which uses an internal cueing framework, and the SpeechVive prosthesis, which employs an external noise cue to elicit louder speech, were studied.

METHOD

Thirty-four persons with hypophonia secondary to idiopathic PD were assigned to one of three groups: LSVT LOUD (n = 12), SpeechVive (n = 12), or a nontreatment clinical control (n = 10). The LSVT LOUD and SpeechVive participants received 8 weeks of voice intervention. Acoustic and respiratory kinematic data were simultaneously collected at pre-, mid- and posttreatment during a monologue speech sample. Intervention outcomes included sound pressure level (SPL), utterance length, lung volume initiation, lung volume termination, and lung volume excursion.

RESULTS

As compared to controls, the LSVT LOUD and SpeechVive participants significantly increased SPL at mid- and posttreatment, thus confirming a positive intervention effect. Treatment-related changes in speech breathing were further identified, including significantly longer utterance lengths (syllables per breath group) at mid- and posttreatment, as compared to pretreatment. The respiratory strategies used to support louder speech varied by group. The LSVT LOUD participants terminated lung volume at significantly lower levels at mid- and posttreatment, as compared to pretreatment. This finding suggests the use of greater expiratory muscle effort by the LSVT LOUD participants to support louder speech. Participants in the SpeechVive group did not significantly alter their respiratory strategies across the intervention period. Single-subject effect sizes highlight the variability in respiratory strategies used across speakers to support louder speech.

CONCLUSIONS

This study provides emerging evidence to suggest that the LSVT LOUD and SpeechVive therapies elicit different respiratory adjustments in persons with PD. The study highlights the need to consider respiratory function when addressing voice targets in persons with PD.

On the Relationship between Speech Intelligibility and Fluency Indicators among English-Speaking Individuals with Parkinson’s Diseases

The purpose of the study is to investigate how much of variance in Parkinson's Disease (PD) individuals' speech intelligibility could be predicted by seven speech fluency indicators (i.e., repetition, omission, distortion, correction, unfilled pauses, filled pauses, and speaking rate). Speech data were retrieved from a database containing a reading task produced by a group of 16 English-speaking individuals with PD (Jaeger, Trivedi & Stadtchnitzer, 2019). The results from a multiple regression indicated that an addition of 54% of variance in the speech intelligibility scores among individuals with PD could be accounted for after the speakers' PD severity level measured based on Hoehn and Yahr's (1967) disease stage was included as a covariate. In addition, omission and correction were the two fluency indicators that contributed to the general intelligibility score in a statistically significant way. Specifically, for every one-unit gain in the number of correction and omission, speech intelligibility scores would decline by 0.687 and 0.131 point (out of a 7-point scale), respectively. The current study hence supported Magee, Copland, and Vogel's (2019) view that the language production abilities and quantified dysarthria measures among individuals with PD should be explored together. Additionally, the clinical implications based on the current findings were discussed.

The effects of vocal exertion on lung volume measurements and acoustics in speakers reporting high and low vocal fatigue

Purpose

Vocal exertion is common and often results in reduced respiratory and laryngeal efficiency. It is unknown, however, whether the respiratory kinematic and acoustic adjustments employed during vocal exertion differ between speakers reporting vocal fatigue and those who do not. This study compared respiratory kinematics and acoustic measures in individuals reporting low and high levels of vocal fatigue during a vocal exertion task.

Methods

Individuals reporting low (N = 20) and high (N = 10) vocal fatigue participated in a repeated measures design study over 2 days. On each day, participants completed a 10-minute vocal exertion task consisting of repeated, loud vowel productions at elevated F0 sustained for maximum phonation time. Respiratory kinematic and acoustic measures were analyzed on the 1^st vowel production (T0), and the vowels produced 2 minutes (T2), 5 minutes (T5), 7 minutes (T7), and 10 minutes (T10) into the vocal exertion task. Vowel durations were also measured at each time point.

Results

No differences in respiratory kinematics were observed between low and high vocal fatigue groups at T0. As the vocal exertion task progressed (T2-T10), individuals reporting high vocal fatigue initiated phonation at lower lung volumes while individuals with low vocal fatigue initiated phonation at higher lung volumes. As the exertion task progressed, total lung volume excursion decreased in both groups. Differences in acoustic measures were observed, as individuals reporting high vocal fatigue produced softer, shorter vowels from T0 through T10.

Conclusions

Individuals reporting high vocal fatigue employed less efficient respiratory strategies during periods of increased vocal demand when compared with individuals reporting low vocal fatigue. Individuals reporting high vocal fatigue had shorter maximum phonation time on loud vowels. Further study should examine the potential screening value of loud maximum phonation time, as well as the clinical implications of the observed respiratory patterns for managing vocal fatigue.

Longitudinal Effects of Parkinson's Disease on Speech Breathing During an Extemporaneous Connected Speech Task

PURPOSE

A critical component to the development of any type of intervention to improve speech production in individuals with Parkinson's disease (PD) is a complete understanding of the speech impairments present at each stage of the disease and how these impairments change with disease progression. The purpose of this longitudinal study was to examine the impact of disease on speech production and speech breathing during an extemporaneous speech task in individuals with PD over the course of approximately 3.5 years.

METHOD

Eight individuals with PD and eight age- and sex-matched control participants produced an extemporaneous connected speech task on two occasions (Time 1 and Time 2) an average of 3 years 7 months apart. Dependent variables included sound pressure level; utterance length; speech rate; lung volume initiation, termination, and excursion; and percent vital capacity per syllable.

RESULTS

From Time 1 to Time 2, individuals with PD demonstrated decreased utterance length and lung volume initiation, termination, and excursion and increased speech rate. Control participants demonstrated decreased utterance length and lung volume termination and increased lung volume excursion and percent vital capacity per syllable from Time 1 to Time 2.

CONCLUSIONS

Changes in speech production and speech breathing variables experienced by individuals with PD over the course of several years are related to their disease process and not typical aging. Changes to speech breathing highlight the need to provide intervention focused on increasing efficient respiratory patterning for speech production.

Manipulation of vocal communication and anxiety through pharmacologic modulation of norepinephrine in the Pink1-/- rat model of Parkinson disease

Vocal deficits and anxiety are common, co-occurring, and interacting signs of Parkinson Disease (PD) that have a devastating impact on quality of life. Both manifest early in the disease process. Unlike hallmark motor signs of PD, neither respond adequately to dopamine replacement therapies, suggesting that their disease-specific mechanisms are at least partially extra-dopaminergic. Because noradrenergic dysfunction is also a defining feature of PD, especially early in the disease progression, drug therapies targeting norepinephrine are being trialed for treatment of motor and non-motor impairments in PD. Research assessing the effects of noradrenergic manipulation on anxiety and vocal impairment in PD, however, is sparse. In this pre-clinical study, we quantified the influence of pharmacologic manipulation of norepinephrine on vocal impairment and anxiety in Pink1-/- rats, a translational model of PD that demonstrates both vocal deficits and anxiety. Ultrasonic vocalization acoustics, anxiety behavior, and limb motor activity were tested twice for each rat: after injection of saline and after one of three drugs. We hypothesized that norepinephrine reuptake inhibitors (atomoxetine and reboxetine) and a β receptor antagonist (propranolol) would decrease vocal impairment and anxiety compared to saline, without affecting spontaneous motor activity. Our results demonstrated that atomoxetine and reboxetine decreased anxiety behavior. Atomoxetine also modulated ultrasonic vocalization acoustics, including an increase in vocal intensity, which is almost always reduced in animal models and patients with PD. Propranolol did not affect anxiety or vocalization. Drug condition did not influence spontaneous motor activity. These studies demonstrate relationships among vocal impairment, anxiety, and noradrenergic systems in the Pink1-/- rat model of PD.

From Speech Acoustics to Communicative Participation in Dysarthria: Toward a Causal Framework

PURPOSE

We proposed and tested a causal instantiation of the World Health Organization's International Classification of Functioning, Disability and Health (ICF) framework, linking acoustics, intelligibility, and communicative participation in the context of dysarthria.

METHOD

Speech samples and communicative participation scores were collected from individuals with dysarthria (n = 32). Speech was analyzed for two acoustic metrics (i.e., articulatory precision and speech rate), and an objective measure of intelligibility was generated from listener transcripts. Mediation analysis was used to evaluate pathways of effect between acoustics, intelligibility, and communicative participation.

RESULTS

We observed a strong relationship between articulatory precision and intelligibility and a moderate relationship between intelligibility and communicative participation. Collectively, data supported a significant relationship between articulatory precision and communicative participation, which was almost entirely mediated through intelligibility. These relationships were not significant when speech rate was specified as the acoustic variable of interest.

CONCLUSION

The statistical corroboration of our causal instantiation of the ICF framework with articulatory acoustics affords important support toward the development of a comprehensive causal framework to understand and, ultimately, address restricted communicative participation in dysarthria.

Comparison of Respiratory Calibration Methods for the Estimation of Lung Volume in Children With and Without Neuromotor Disorders

PURPOSE

The primary purpose of this study was to validate common respiratory calibration methods for estimating lung volume in children.

METHOD

Respiratory kinematic data were collected via inductive plethysmography from 81 typically developing children and nine children with neuromotor disorders. Correction factors for the rib cage and abdomen were calculated using three different methods: (a) least squares method with both rib cage and abdomen corrections (LsqRC/AB), (b) least squares method with rib cage correction only (LsqRC), and (c) a standard 2:1 rib-cage-to-abdomen ratio (Banzett). Correction factors for the LsqRC/AB and LsqRC methods were calculated with and without the use of the speech-like breathing calibration task. Lung volume estimation errors were calculated by comparing the estimated lung volumes based on the correction factors and the actual lung volumes acquired from a spirometer, normalized to each participant's vital capacity.

RESULTS

For typically developing children, the LsqRC/AB method resulted in significantly smaller lung volume estimation errors compared with other methods. Lung volume estimation errors decreased as age increased for each method. For the children with neuromotor disorders, the LsqRC/AB and LsqRC methods resulted in significantly smaller lung volume estimation errors than the Banzett method but were not significantly different from one another. There were no significant differences in lung volume estimation errors for the LsqRC/AB and LsqRC methods when the correction factors were calculated with and without the speech-like breathing calibration task.

CONCLUSION

The LsqRC/AB method exclusively utilizing the rest breathing calibration task is the most accurate and efficient respiratory calibration method for use with children with and without neuromotor disorders at this time.

Intelligibility Across a Reading Passage: The Effect of Dysarthria and Cued Speaking Styles

OBJECTIVE

Reading a passage out loud is a commonly used task in the perceptual assessment of dysarthria. The extent to which perceptual characteristics remain unchanged or stable over the time course of a passage is largely unknown. This study investigated crowdsourced visual analogue scale (VAS) judgments of intelligibility across a reading passage as a function of cued speaking styles commonly used in treatment to maximize intelligibility.

PATIENTS AND METHOD

The Hunter passage was read aloud in habitual, slow, loud, and clear speaking styles by 16 speakers with Parkinson's disease (PD), 30 speakers with multiple sclerosis (MS), and 32 control speakers. VAS judgments of intelligibility from three fragments representing the beginning, middle, and end of the reading passage were obtained from 540 crowdsourced online listeners.

RESULTS

Overall passage intelligibility was reduced for the two clinical groups relative to the control group. All speaker groups exhibited intelligibility variation across the reading passage, with trends of increased intelligibility toward the end of the reading passage. For control speakers and speakers with PD, patterns of intelligibility variation across passage reading did not differ with speaking style. For the MS group, intelligibility variation across the passage was dependent on speaking style.

CONCLUSIONS

The presence of intelligibility variation within a reading passage warrants careful selection of speech materials in research and clinical practice. Results further indicate that the crowdsourced VAS rating paradigm is useful to document intelligibility in a reading passage for different cued speaking styles commonly used in treatment for dysarthria.

Thyroarytenoid Muscle Gene Expression in a Rat Model of Early-Onset Parkinson's Disease

OBJECTIVES/HYPOTHESIS

Voice disorders in Parkinson's disease (PD) are early-onset, manifest in the preclinical stages of the disease, and negatively impact quality of life. The complete loss of function in the PTEN-induced kinase 1 gene (Pink1) causes a genetic form of early-onset, autosomal recessive PD. Modeled after the human inherited mutation, the Pink1-/- rat demonstrates significant cranial sensorimotor dysfunction including declines in ultrasonic vocalizations. However, the underlying genetics of the vocal fold thyroarytenoid (TA) muscle that may contribute to vocal deficits has not been studied. The aim of this study was to identify differentially expressed genes in the TA muscle of 8-month-old male Pink1-/- rats compared to wildtype controls.

STUDY DESIGN

Animal experiment with control.

METHODS

High throughput RNA sequencing was used to examine TA muscle gene expression in adult male Pink1-/- rats and wildtype controls. Weighted Gene Co-expression Network Analysis was used to construct co-expression modules to identify biological networks, including where Pink1 was a central node. The ENRICHR tool was used to compare this gene set to existing human gene databases.

RESULTS

We identified 134 annotated differentially expressed genes (P < .05 cutoff) and observed enrichment in the following biological pathways: Parkinson's disease (Casp7, Pink1); Parkin-Ubiquitin proteasome degradation (Psmd12, Psmd7); MAPK signaling (Casp7, Ppm1b, Ppp3r1); and inflammatory TNF-α, Nf-κB Signaling (Casp7, Psmd12, Psmd7, Cdc34, Bcl7a, Peg3).

CONCLUSIONS

Genes and pathways identified here may be useful for evaluating the specific mechanisms of peripheral dysfunction including within the laryngeal muscle and have potential to be used as experimental biomarkers for treatment development.

LEVEL OF EVIDENCE

NA Laryngoscope, 131:E2874-E2879, 2021.

Mitigating the Effects of Acute Vocal Exertion in Individuals With Vocal Fatigue

OBJECTIVES/HYPOTHESIS

To investigate the effects of acute vocal exertion on individuals with vocal fatigue and to determine whether semi-occluded vocal tract exercises (SOVTEs) are more effective than vocal rest in mitigating acute effects.

STUDY DESIGN

Prospective, repeated-measures design.

METHODS

On consecutive days, 10 individuals (6 males, 4 females) with scores indicating vocal fatigue on the Vocal Fatigue Index completed two 10-minute vocal exertion tasks. Vocal rest or SOVTEs were interspersed in counterbalanced order between exertion tasks. Respiratory kinematic, acoustic, aerodynamic, and self-perceptual measures were collected at baseline, following vocal exertion, following SOVTE/vocal rest, and following the second exertion task.

RESULTS

Acute vocal exertion worsened phonation threshold pressure (P < .001) and vocal effort (P < .001) and reduced maximum fundamental frequency (P < .001). Speech was terminated at lower lung volumes following vocal exertion (decreased lung volume termination [LVT], P < .001). Exertion-induced changes in vocal effort and LVT were significantly reversed by both vocal rest and SOVTE. Detrimental changes in voice measures reoccurred following the second vocal exertion task. SOVTE and vocal rest protected against changes in respiratory kinematics when vocal exertion was resumed.

CONCLUSIONS

Vocal exertion impacted laryngeal, respiratory, and self-perceptual measures in individuals with vocal fatigue. Both SOVTE and vocal rest partially mitigated changes in voice measures and prompted more efficient respiratory strategies that were maintained when vocal exertion resumed. These data increase our understanding of how individuals with vocal fatigue respond to vocal exertion tasks and offer preliminary guidance for optimal clinical recommendations.

LEVEL OF EVIDENCE

3 Laryngoscope, 131:2732-2739, 2021.

The effects of a simulated fMRI environment on voice intensity in individuals with Parkinson's disease hypophonia and older healthy adults

PURPOSE

Functional magnetic resonance imaging (fMRI) has promise for understanding neural mechanisms of neurogenic speech and voice disorders. However, performing vocal tasks within the fMRI environment may not always be analogous to performance outside of the scanner. Using a mock MRI scanner, this study examines the effects of a simulated scanning environment on vowel intensity in individuals with Parkinson's disease (PD) and hypophonia and older healthy control (OHC) participants.

METHOD

Thirty participants (15 PD, 15 OHC) performed a sustained /ɑ/ vowel production task in three conditions: 1) Upright, 2) Mock Scanner + No Noise, and 3) Mock Scanner + MRI noise. We used a linear mixed-effects (multi-level) model to evaluate the contributions of group and recording environment to vowel intensity. A second linear mixed-effects model was also used to evaluate the contributions of PD medication state (On vs. Off) to voice intensity.

RESULTS

Vowel intensity was significantly lower for PD compared to the OHC group. The intensity of vowels produced in the Upright condition was significantly lower compared to the Mock Scanner + No Noise condition, while vowel intensity in the Mock Scanner + MRI Noise condition was significantly higher compared to the Mock Scanner + No Noise condition. A group by condition interaction also indicated that the addition of scanner noise had a greater impact on the PD group. A second analysis conducted within the PD group showed no effects of medication state on vowel intensity.

CONCLUSION

Our findings demonstrate that performance on voice production tasks is altered for PD and OHC groups when translated into the fMRI environment, even in the absence of acoustic scanner noise. For fMRI studies of voice in PD hypophonia, careful thought should be given to how the presence of acoustic noise may differentially affect PD and OHC, for both group and task comparisons.

Quantification of brainstem norepinephrine relative to vocal impairment and anxiety in the Pink1-/- rat model of Parkinson disease

Vocal communication impairment and anxiety are co-occurring and interacting signs of Parkinson Disease (PD) that are common, poorly understood, and under-treated. Both vocal communication and anxiety are influenced by the noradrenergic system. In light of this shared neural substrate and considering that noradrenergic dysfunction is a defining characteristic of PD, tandem investigation of vocal impairment and anxiety in PD relative to noradrenergic mechanisms is likely to yield insights into the underlying disease-specific causes of these impairments. In order to address this gap in knowledge, we assessed vocal impairment and anxiety behavior relative to brainstem noradrenergic markers in a genetic rat model of early-onset PD (Pink1-/-) and wild type controls (WT). We hypothesized that 1) brainstem noradrenergic markers would be disrupted in Pink1-/-, and 2) brainstem noradrenergic markers would be associated with vocal acoustic changes and anxiety level. Rats underwent testing of ultrasonic vocalization and anxiety (elevated plus maze) at 4, 8, and 12 months of age. At 12 months, brainstem norepinephrine markers were quantified with immunohistochemistry. Results demonstrated that vocal impairment and anxiety were increased in Pink1-/- rats, and increased anxiety was associated with greater vocal deficit in this model of PD. Further, brainstem noradrenergic markers including TH and α1 adrenoreceptor immunoreactivity in the locus coeruleus, and β1 adrenoreceptor immunoreactivity in vagal nuclei differed by genotype, and were associated with vocalization and anxiety behavior. These findings demonstrate statistically significant relationships among vocal impairment, anxiety, and brainstem norepinephrine in the Pink1-/- rat model of PD.

Restoration Strategies Following Short-Term Vocal Exertion in Healthy Young Adults

Purpose This study aims to investigate the effects of a 10-min vocal exertion task on voice and respiratory measures, to determine whether restorative strategies can mitigate these effects after cessation of exertion, and to assess whether these strategies continue to reduce these detrimental effects when vocal exertion is resumed. Method A prospective, repeated-measures design was used. On consecutive days, 20 participants (equal men and women) completed two vocal exertion tasks separated by 10 min of restoration strategies: vocal rest or controlled phonation (low-level tissue mobilization using straw phonation). Voice and respiratory data were collected at baseline, following the first exertion task, after restoration strategies, and after the second exertion task. Outcome measures included (a) vocal effort, (b) phonation threshold pressure, (c) maximum and minimum fundamental frequencies, (d) cepstral peak prominence of connected speech, (e) lung volume initiation and termination, (f) percent vital capacity expended per syllable, and (g) number of syllables per breath group. Results A worsening of phonation threshold pressure (p < .001), vocal effort (p < .001), and increase of minimum fundamental frequency (p = .007) were observed after vocal exertion. Lung volume initiation (p < .001) and lung volume termination (p < .001) increased. These changes were largely reversed by restoration strategies, but only controlled phonation prevented exertion-induced changes in respiratory kinematic measures on a subsequent vocal exertion task. Conclusions Exertion-induced voice changes occur rapidly and may be mitigated by either controlled phonation or vocal rest. Controlled phonation is recommended as a superior strategy due to evidence of a protective effect on a successive vocal exertion task.

Speech Intensity Response to Altered Intensity Feedback in Individuals With Parkinson's Disease

Purpose Hypophonia (low speech intensity) is the most common speech symptom experienced by individuals with Parkinson's disease (IWPD). Previous research suggests that, in IWPD, there may be abnormal integration of sensory information for motor production of speech intensity. In the current study, intensity of auditory feedback was systematically manipulated (altered in both positive and negative directions) during sensorimotor conditions that are known to modulate speech intensity in everyday contexts in order to better understand the role of auditory feedback for speech intensity regulation. Method Twenty-six IWPD and 24 neurologically healthy controls were asked to complete the following tasks: converse with the experimenter, start vowel production, and read sentences at a comfortable loudness, while hearing their own speech intensity randomly altered. Altered intensity feedback conditions included 5-, 10-, and 15-dB reductions and increases in the feedback intensity. Speech tasks were completed in no noise and in background noise. Results IWPD displayed a reduced response to the altered intensity feedback compared to control participants. This reduced response was most apparent when participants were speaking in background noise. Specific task-based differences in responses were observed such that the reduced response by IWPD was most pronounced during the conversation task. Conclusions The current study suggests that IWPD have abnormal processing of auditory information for speech intensity regulation, and this disruption particularly impacts their ability to regulate speech intensity in the context of speech tasks with clear communicative goals (i.e., conversational speech) and speaking in background noise.

Respiratory Dysfunctions in Parkinson's Disease Patients

Respiratory dysfunctions have been associated with Parkinson's disease since the first observations of the disease in 1817. Patients with Parkinson's disease frequently present respiratory disorders with obstructive ventilatory patterns and restrictive modifications, as well as limitations in respiratory volumes. In addition, respiratory impairments are observed due to the rigidity and kyphosis that Parkinson's disease patients experience. Subsidiary pulmonary complications can also appear as side effects of medication. Silent aspiration can be the cause of pneumonia in Parkinson's disease. Pulmonary dysfunction is one of the main factors that leads to the morbidity and mortality of patients with Parkinson's disease. Here, we performed a narrative review of the literature and reviewed studies on dyspnea, lung volumes, respiratory muscle function, sleep breathing disorders, and subsidiary speech and swallow impairments related to pulmonary dysfunction in patients with Parkinson's disease.

Obtaining Objective Clinical Measures During Telehealth Evaluations of Dysarthria

Purpose COVID-19 has shifted models of health care delivery, requiring the rapid adoption of telehealth, despite limited evidence and few resources to guide speech-language pathologists. Management of dysarthria presents specific challenges in the telehealth modality. Evaluations of dysarthria typically rely heavily on perceptual judgments, which are difficult to obtain via telehealth given a variety of technological factors such as inconsistencies in mouth-to-microphone distance, changes to acoustic properties based on device settings, and possible interruptions in connection that may cause video freezing. These factors limit the validity, reliability, and clinicians' certainty of perceptual speech ratings via telehealth. Thus, objective measures to supplement the assessment of dysarthria are essential. Method This tutorial outlines how to obtain objective measures in real time and from recordings of motor speech evaluations to support traditional perceptual ratings in telehealth evaluations of dysarthria. Objective measures include pause patterns, utterance length, speech rate, diadochokinetic rates, and overall speech severity. We demonstrate, through clinical case vignettes, how these measures were completed following three clinical telehealth evaluations of dysarthria conducted via Zoom during the COVID-19 pandemic. This tutorial describes how each of these objective measures were utilized, in combination with subjective perceptual analysis, to determine deviant speech characteristics and their etiology, develop a patient-specific treatment plan, and track change over time. Conclusion Utilizing objective measures as an adjunct to perceptual ratings for telehealth dysarthria evaluations is feasible under real-world pandemic conditions and can be used to enhance the quality and utility of these evaluations.

The Impact of Parkinson's Disease on Breath Pauses and Their Relationship to Speech Impairment: A Longitudinal Study

Purpose The purposes of this longitudinal study were to (a) examine the impact of Parkinson's disease (PD) progression on breath pause patterns and speech and linguistic errors and (b) determine the extent to which breath pauses and speech and linguistic errors contribute to speech impairment. Method Eight individuals with PD and eight age- and sex-matched control participants produced a reading passage on two occasions (Time 1 and Time 2) 3 years and 7 months apart on average. Two speech-language pathologists rated the severity of speech impairment for all participants at each time. Dependent variables included the location of each breath pause relative to syntax and punctuation as well as the number of disfluencies and mazes. Results At Time 1, there were no significant differences between the groups regarding breath pause patterns. At Time 2, individuals with PD produced significantly fewer breath pauses at major syntactic boundaries and periods as well as significantly more breath pauses at locations with no punctuation than control participants. Individuals with PD produced a significantly greater number of disfluencies than control participants at both time points. There were no significant differences between the groups in the number of mazes produced at either time point. Together, the number of mazes and the percentage of breath pauses at locations with no punctuation explained 50% of the variance associated with the ratings of severity of speech impairment. Conclusion These results highlight the importance of targeting both respiratory physiological and cognitive-linguistic systems in order to improve speech production in individuals with PD.

Speaking dyspnea in Parkinson's disease: Preliminary findings

PURPOSE

To determine if people with Parkinson's disease (PD) experience dyspnea (breathing discomfort) during speaking.

METHOD

The participants were 11 adults with PD and 22 healthy adults (11 young, 11 old). Participants were asked to recall experiences of breathing discomfort across different speaking contexts and provide ratings of those experiences (Retrospective ratings); then they rated the breathing discomfort experienced while performing speaking tasks that were designed to differ in respiratory demands (immediate Post-Speaking ratings).

RESULTS

Participants with PD reported experiencing breathing discomfort during speaking significantly more frequently (approximately 60 % of the time) than did healthy participants (less than 20 % of the time). Retrospective ratings did not differ significantly from Post-Speaking ratings. Breathing discomfort was experienced by the fewest number of participants with PD for Conversation (two) and Extemporaneous Speaking (three) and by the greatest number for Extended Reading (ten) and Long Counting (nine), although the magnitude of the ratings generally reflected only "Slight" discomfort. Breathing discomfort was most frequently described as air hunger and breathing work, less frequently as mental effort, and very rarely as lung tightness. A few participants with PD reported experiencing emotions associated with their breathing discomfort and most reported using strategies to avoid breathing discomfort in their daily lives.

CONCLUSIONS

Individuals with PD are more apt to experience speaking dyspnea than healthy individuals, especially when speaking for extended periods or when using long breath groups. Such dyspnea may contribute to a tendency to avoid speaking situations and thereby impair quality of life.

Age Norms for Auditory-Perceptual Neurophonetic Parameters: A Prerequisite for the Assessment of Childhood Dysarthria

Purpose The aim of this study was to collect auditory-perceptual data on established symptom categories of dysarthria from typically developing children between 3 and 9 years of age, for the purpose of creating age norms for dysarthria assessment. Method One hundred forty-four typically developing children (3;0-9;11 [years;months], 72 girls and 72 boys) participated. We used a computer-based game specifically designed for this study to elicit sentence repetitions and spontaneous speech samples. Speech recordings were analyzed using the auditory-perceptual criteria of the Bogenhausen Dysarthria Scales, a standardized German assessment tool for dysarthria in adults. The Bogenhausen Dysarthria Scales (scales and features) cover clinically relevant dimensions of speech and allow for an evaluation of well-established symptom categories of dysarthria. Results The typically developing children exhibited a number of speech characteristics overlapping with established symptom categories of dysarthria (e.g., breathy voice, frequent inspirations, reduced articulatory precision, decreased articulation rate). Substantial progress was observed between 3 and 9 years of age, but with different developmental trajectories across different dimensions. In several areas (e.g., respiration, voice quality), 9-year-olds still presented with salient developmental speech characteristics, while in other dimensions (e.g., prosodic modulation), features typically associated with dysarthria occurred only exceptionally, even in the 3-year-olds. Conclusions The acquisition of speech motor functions is a prolonged process not yet completed with 9 years. Various developmental influences (e.g., anatomic-physiological changes) shape children's speech specifically. Our findings are a first step toward establishing auditory-perceptual norms for dysarthria in children of kindergarten and elementary school age. Supplemental Material https://doi.org/10.23641/asha.12133380.

The Accuracy of Respiratory Calibration Methods for Estimating Lung Volume During Speech Breathing: A Comparison of Four Methods Across Three Adult Cohorts

Purpose This study evaluated the accuracy of respiratory calibration methods for estimating lung volume during speech breathing. Method Respiratory kinematic data were acquired via inductance plethysmography in 32 young adults, 22 older adults, and 13 older adults with Parkinson's disease (PD). Raw rib cage (RC) and abdomen (AB) signals (V) were calibrated to liters using 4 correction methods: (a) isovolume maneuvers, (b) a constant 2:1 RC-to-AB ratio, (c) least squares method with RC correction only (LsqRC), and (d) least squares method with both RC and AB corrections (LsqRC/AB). Mean percent error, the absolute difference between estimated and actual lung volumes then normalized to each speaker's vital capacity, was calculated for each method. Results For young adults, the LsqRC/AB method significantly reduced mean percent error compared to all other methods. Although LsqRC/AB also resulted in smaller errors for older adults and adults with PD, LsqRC/AB and LsqRC were not significantly different from one another in these groups. Conclusion The LsqRC/AB method reduces errors across all cohorts, but older adults and adults with PD also have reduced errors when using LsqRC. Further research should investigate both least squares methods across larger age and disease severity ranges.

Tongue- and Jaw-Specific Articulatory Underpinnings of Reduced and Enhanced Acoustic Vowel Contrast in Talkers With Parkinson's Disease

Purpose This study sought to identify the articulator-specific mechanisms that underlie reduced and enhanced acoustic vowel contrast in talkers with dysarthria due to Parkinson's disease (PD). Method Seventeen talkers with mild-moderate dysarthria due to PD and 17 controls completed a sentence repetition task using typical, slow, loud, and clear speech. Tongue and jaw articulatory movements were recorded using 3D electromagnetic articulography. Independent tongue displacements, jaw displacements, and acoustic vowel contrast were calculated for the diphthong /aɪ/ embedded in the word kite. Results During typical speech, independent tongue displacement, but not jaw displacement, contributed significantly to the intertalker variance in acoustic vowel contrast. Loudness-related acoustic vowel contrast gains were predominantly jaw driven in controls but driven by the tongue and jaw in talkers with PD. Further, in both groups, clarity-related acoustic vowel contrast gains were predominantly jaw driven. Finally, in both groups, rate-related acoustic vowel contrast gains were predominantly tongue driven; however, the jaw also contributed. These jaw contributions were greater in the PD group than in the control group. Conclusions Findings suggest that a tongue-specific articulatory impairment underlies acoustic vowel contrast deterioration in talkers with PD, at least during the early stages of speech decline. Findings further suggest that slow speech engages the impaired tongue more than loud and clear speech in talkers with PD. However, slow speech was also associated with an abnormally strong jaw response in these talkers, which suggests that a compensatory articulatory behavior may also be elicited.

Filled Pauses as a Special Case of Automatic Speech Behaviors and the Effect of Parkinson's Disease

Purpose In Parkinson's disease (PD), there are significant changes in the basal ganglia, a structure known to be important for controlling automatic responses to cues. Changes to the basal ganglia in PD impair an individual's ability to trigger a behavior in response to cues, but more so in response to internal cues more than external ones. Filled pauses are considered a subconscious or automatic speech response to an internal cue that there are difficulties with ongoing communication. Typical speakers use filled pauses (such as uh or um) to mark silent pauses. The purpose of this study was to examine how automatic speech responses are impacted in PD by looking at filled and silent pausing behaviors, extending our understanding of the role of the basal ganglia in automatic behaviors. We hypothesized that individuals with PD would use fewer filled pauses and longer silent pauses. We also hypothesized that longer pauses would be more likely to be marked with filled pauses and that this relationship would be weaker in speakers with PD. Method Speech samples were collected via a story-retelling task from 15 individuals with PD and 18 age-matched controls. Duration and frequency of filled and silent pauses were measured using spectrographic analysis. Number and duration of marked silent pauses (those consecutive with 1 or more filled pauses) were measured. The t tests and analyses of variance were used to test our hypotheses. Results There was no significant difference in the number of silent pauses between groups, but the duration of silent pauses was significantly greater for individuals with PD. Despite this, individuals with PD produced significantly fewer filled pauses and fewer marked silent pauses. For both groups, longer silent pauses were more likely to be marked by filled pauses, but individuals with PD marked a smaller percentage of silent pauses at longer durations than controls. Conclusions Producing fewer marked silent pauses, coupled with longer silent pauses, reduces natural cues to discourse and puts people with PD at greater risk of sounding unnatural and losing their communicative turn. These results suggest that automatic responses regarding speech production difficulties are impaired by PD. This interpretation fits with nonspeech literature where automatic responses have been demonstrated to be impaired in PD.

Effects of Concurrent Manual Task Performance on Connected Speech Acoustics in Individuals With Parkinson Disease

Purpose Prior investigations suggest that simultaneous performance of more than 1 motor-oriented task may exacerbate speech motor deficits in individuals with Parkinson disease (PD). The purpose of the current investigation was to examine the extent to which performing a low-demand manual task affected the connected speech in individuals with and without PD. Method Individuals with PD and neurologically healthy controls performed speech tasks (reading and extemporaneous speech tasks) and an oscillatory manual task (a counterclockwise circle-drawing task) in isolation (single-task condition) and concurrently (dual-task condition). Results Relative to speech task performance, no changes in speech acoustics were observed for either group when the low-demand motor task was performed with the concurrent reading tasks. Speakers with PD exhibited a significant decrease in pause duration between the single-task (speech only) and dual-task conditions for the extemporaneous speech task, whereas control participants did not exhibit changes in any speech production variable between the single- and dual-task conditions. Conclusions Overall, there were little to no changes in speech production when a low-demand oscillatory motor task was performed with concurrent reading. For the extemporaneous task, however, individuals with PD exhibited significant changes when the speech and manual tasks were performed concurrently, a pattern that was not observed for control speakers. Supplemental Material https://doi.org/10.23641/asha.8637008.

Effect of Clear Speech on the Duration of Silent Intervals at Syntactic and Phonemic Boundaries in the Speech of Individuals With Parkinson Disease

Purpose The purpose of the current investigation was to determine the extent to which individuals with and without Parkinson disease (PD) modified silent interval durations when using a clear speaking style. Method Ten individuals with idiopathic PD and 10 older adult control speakers produced a reading passage using both habitual and clear speaking styles. Silent intervals lasting 15 ms and longer were identified and extracted. Each silent interval was categorized according to the surrounding syntactic context of the reading passage. In addition, voiceless stop gaps that occurred within words, phrases, or clauses were categorized by the preceding phonemic context. Results Statistical analyses revealed that all participants increased silent interval duration with a clear speaking style at inter-sentence and intra-sentence syntactic boundaries. Compared to controls, individuals with PD exhibited significantly less increase in silent interval durations at these syntactic boundaries. Control speakers also increased silent stop gap durations in the clear speaking style regardless of preceding phonemic context. Individuals with PD, however, only increased stop gap duration when the silent interval was preceded by a sonorant. Conclusion These findings suggest that speakers with PD exhibit less clarity-related increase in silent interval duration than control speakers. In addition, speakers with PD exhibited significant increases in silent interval duration that coincided with syntactic boundaries of the reading passage but little to no clarity-related modulation of stop gap intervals. Therefore, these data suggest that speakers with PD exhibited changes in silent interval durations that were more so associated with modulation of speech prosody than articulation when using a clearer speaking style.

Language planning and pauses in story retell: Evidence from aging and Parkinson's disease

We examined if and how pauses during connected speech reflect cognitive processes underlying language formulation in typical aging and Parkinson's disease (PD), beyond respiratory and motor-speech mechanisms. The frequency of silent pauses was measured (a) in relation to different linguistic (independent clausal, subordinate clausal, phrasal, and atypical) boundaries and (b) proficiency measures of language production in young adults, older adults, and individuals with PD. At the group level, aging, but not PD, resulted in increased pausing at atypical linguistic locations. However, in both aging and PD, individuals' reduced production of syntactically complex sentences was associated with more frequent pausing at various typical prosodic (clausal or phrasal) boundaries. Frequency of pauses was not associated with individual performance in grammaticality of sentences and lexical-semantic production. Overall, the present study demonstrated that production of pauses during connected speech reflects cognitive processes underlying language production beyond respiratory-physiological processes of communication. Assessing production of pauses in connected speech may augment, but does not replace, assessment of language production in clinical practice.

Characterizing the distribution of silent intervals in the connected speech of individuals with Parkinson disease

The purpose of the current investigation was to examine a statistical approach to differentiating shorter silent intervals (e.g., stop gaps) from longer silent intervals (e.g., pause) at varying syntactic locations within a reading passage to better characterize articulatory and prosodic aspects of speech timing in Parkinson disease (PD). Silent intervals 15 ms and longer were extracted from reading sample. Logarithmic transformation of the silent interval durations yielded a bimodal distribution. Gaussian Mixture Model analysis was used to statistically differentiate the first mode (Mode 1) that corresponded to short silent intervals from the second mode (Mode 2) that corresponded to longer silent intervals. The syntactic context surrounding each silent interval was also categorized. Results revealed that the large majority of silent intervals that occurred within a clause, phrase, or word were assigned to Mode 1, while the majority of silent intervals that coincided with sentence-ending punctuation were assigned to Mode 2. Results revealed that Mode 1 intervals were slightly, but significantly longer for speakers with PD (Mean = 52.48 ms, SE = 3.23) compared to controls (Mean = 44.67 ms, SE = 2.00). Examination of the surrounding syntactic context revealed that this difference occurred at between-word boundaries contained within a phrase or clause. No between group differences were observed for the other inter- and intra-sentence syntactic boundaries or Mode 2 intervals. This study outlines a data-based approach to differentiating short between- and within-word intervals from longer silent intervals or pauses that reflect the prosodic and syntactic structure of a reading passage. Using this approach, the current data suggest that speakers with PD exhibit longer short silent intervals than controls, potentially reflecting a slight delay in the fluent segment-to-segment transition between words.

Characteristics of Speech Rate in Children With Cerebral Palsy: A Longitudinal Study

PURPOSE

The purpose of this longitudinal study was to examine the effect of time and sentence length on speech rate and its characteristics, articulation rate and pauses, within 2 groups of children with cerebral palsy (CP).

METHOD

Thirty-four children with CP, 18 with no speech motor involvement and 16 with speech motor involvement, produced sentences of varying lengths at 3 time points that were 1 year apart (mean age = 56 months at first time point). Dependent measures included speech rate, articulation rate, proportion of time spent pausing, and average number and duration of pauses.

RESULTS

There were no significant effects of time. For children with no speech motor involvement, speech rate increased with longer sentences due to increased articulation rate. For children with speech motor involvement, speech rate did not change with sentence length due to significant increases in the proportion of time spent pausing and average number of pauses in longer sentences.

CONCLUSIONS

There were no significant age-related differences in speech rate in children with CP regardless of group membership. Sentence length differentially impacted speech rate and its characteristics in both groups of children with CP. This may be due to cognitive-linguistic and/or speech motor control factors.

Walking while talking: Young adults flexibly allocate resources between speech and gait

BACKGROUND

Walking while talking is an ideal multitask behavior to assess how young healthy adults manage concurrent tasks as it is well-practiced, cognitively demanding, and has real consequences for impaired performance in either task. Since the association between cognitive tasks and gait appears stronger when the gait task is more challenging, gait challenge was systematically manipulated in this study.

OBJECTIVE

To understand how young adults accomplish the multitask behavior of walking while talking as the gait challenge was systematically manipulated.

METHODS

Sixteen young adults (21 ± 1.6 years, 9 males) performed three gait tasks with and without speech: unobstructed gait (easy), obstacle crossing (moderate), obstacle crossing and tray carrying (difficult). Participants also provided a speech sample while seated for a baseline indicator of speech. The speech task was to speak extemporaneously about a topic (e.g. first car). Gait speed and the duration of silent pauses during speaking were determined. Silent pauses reflect cognitive processes involved in speech production and language planning.

RESULTS

When speaking and walking without obstacles, gait speed decreased (relative to walking without speaking) but silent pause duration did not change (relative to seated speech). These changes are consistent with the idea that, in the easy gait task, participants placed greater value on speech pauses than on gait speed, likely due to the negative social consequences of impaired speech. In the moderate and difficult gait tasks both parameters changed: gait speed decreased and silent pauses increased.

CONCLUSION

Walking while talking is a cognitively demanding task for healthy young adults, despite being a well-practiced habitual activity. These findings are consistent with the integrated model of task prioritization from Yogev-Seligmann et al., [1].

Rhythmic performance in hypokinetic dysarthria: Relationship between reading, spontaneous speech and diadochokinetic tasks

•We investigated speech rhythm in people with Parkinson’s Disease (PwPD) and controls. •Even mildly affected PwPD differed from controls in their rhythmic performance. •PwPD showed less difference between reading and spontaneous speech. •Spontaneous speech highlighted more differences between speakers than reading. •DDK performance did not relate to rhythmic behaviour in connected speech.

Acoustic changes in the speech of children with cerebral palsy following an intensive program of dysarthria therapy

BACKGROUND

The speech intelligibility of children with dysarthria and cerebral palsy has been observed to increase following therapy focusing on respiration and phonation.

AIMS

To determine if speech intelligibility change following intervention is associated with change in acoustic measures of voice.

METHODS & PROCEDURES

We recorded 16 young people with cerebral palsy and dysarthria (nine girls; mean age 14 years, SD = 2; nine spastic type, two dyskinetic, four mixed; one Worster-Drought) producing speech in two conditions (single words, connected speech) twice before and twice after therapy focusing on respiration, phonation and rate. In both single-word and connected speech we measured vocal intensity (root mean square-RMS), period-to-period variability (Shimmer APQ, Jitter RAP and PPQ) and harmonics-to-noise ratio (HNR). In connected speech we also measured mean fundamental frequency, utterance duration in seconds and speech and articulation rate (syllables/s with and without pauses respectively). All acoustic measures were made using Praat. Intelligibility was calculated in previous research.

OUTCOMES & RESULTS

In single words statistically significant but very small reductions were observed in period-to-period variability following therapy: Shimmer APQ -0.15 (95% CI = -0.21 to -0.09); Jitter RAP -0.08 (95% CI = -0.14 to -0.01); Jitter PPQ -0.08 (95% CI = -0.15 to -0.01). No changes in period-to-period perturbation across phrases in connected speech were detected. However, changes in connected speech were observed in phrase length, rate and intensity. Following therapy, mean utterance duration increased by 1.11 s (95% CI = 0.37-1.86) when measured with pauses and by 1.13 s (95% CI = 0.40-1.85) when measured without pauses. Articulation rate increased by 0.07 syllables/s (95% CI = 0.02-0.13); speech rate increased by 0.06 syllables/s (95% CI = < 0.01-0.12); and intensity increased by 0.03 Pascals (95% CI = 0.02-0.04). There was a gradual reduction in mean fundamental frequency across all time points (-11.85 Hz, 95% CI = -19.84 to -3.86). Only increases in the intensity of single words (0.37 Pascals, 95% CI = 0.10-0.65) and reductions in fundamental frequency (-0.11 Hz, 95% CI = -0.21 to -0.02) in connected speech were associated with gains in intelligibility.

CONCLUSIONS & IMPLICATIONS

Mean reductions in impairment in vocal function following therapy observed were small and most are unlikely to be clinically significant. Changes in vocal control did not explain improved intelligibility.

Intelligibility of Noise-Adapted and Clear Speech in Child, Young Adult, and Older Adult Talkers

PURPOSE

This study examined intelligibility of conversational and clear speech sentences produced in quiet and in noise by children, young adults, and older adults. Relative talker intelligibility was assessed across speaking styles.

METHOD

Sixty-one young adult participants listened to sentences mixed with speech-shaped noise at -5 dB signal-to-noise ratio. The analyses examined percent correct scores across conversational, clear, and noise-adapted conditions and the three talker groups. Correlation analyses examined whether talker intelligibility is consistent across speaking style adaptations.

RESULTS

Noise-adapted and clear speech significantly enhanced intelligibility for young adult listeners. The intelligibility improvement varied across the three talker groups. Notably, intelligibility benefit was smallest for children's speaking style modifications. Listeners also perceived speech produced in noise by older adults to be less intelligible compared to the younger talkers. Talker intelligibility was correlated strongly between conversational and clear speech in quiet, but not for conversational speech produced in quiet and in noise.

CONCLUSIONS

Results provide evidence that intelligibility variation related to age and communicative barrier has the potential to aid clinical decision making for individuals with speech disorders, particularly dysarthria.

The Impact of Expiratory Muscle Strength Training on Speech Breathing in Individuals With Parkinson's Disease: A Preliminary Study

PURPOSE

The purpose of this study was to examine the impact of expiratory muscle strength training on speech breathing and functional speech outcomes in individuals with Parkinson's disease (PD).

METHOD

Twelve individuals with PD were seen once a week for 8 weeks: 4 pretraining (baseline) sessions followed by a 4-week training period. Posttraining data were collected at the end of the 4th week of training. Maximum expiratory pressure, an indicator of expiratory muscle strength, and lung volume at speech initiation were the primary outcome measures. Secondary outcomes included lung volume at speech termination, lung volume excursion, utterance length, and vocal intensity. Data were collected during a spontaneous speech sample. Individual effect sizes > 1 were considered significant.

RESULTS

Maximum expiratory pressure increased in a majority of participants after training. Training resulted in 2 main respiratory patterns: increasing or decreasing lung volume initiation. Lung volume termination and excursion, utterance length, and vocal loudness were not consistently altered by training.

CONCLUSIONS

Preliminary evidence suggests that the direct physiologic intervention of the respiratory system via expiratory muscle strength training improves speech breathing in individuals with PD, with participants using more typical lung volumes for speech following treatment.

Subcortical Effects on Voice and Fluency in Dysarthria: Observations from Subthalamic Nucleus Stimulation

OBJECTIVE

Parkinson's disease (PD), caused by basal ganglia dysfunction, is associated with motor disturbances including dysarthria. Stimulation of the subthalamic nucleus, a preferred treatment targeting basal ganglia function, improves features of the motor disorder, but has uncertain effects on speech.We studied speech during contrasting stimulation states to reveal subcortical effects on voice and articulation. Measures were made on selected samples of spontaneous and repeated speech.

METHODS

Persons with Parkinson's disease (PWP) who had undergone bilateral deep brain stimulation of the subthalamic nucleus (DBS-STN) provided spontaneous speech samples and then repeated portions of their monologue both on and off stimulation. Excerpts were presented in a listening protocol probing intelligibility. Also analysed were a continuous phrase repetition task and a second spontaneous speech sample. Fundamental frequency (F0), harmonic-to-noise ratio (HNR), jitter, shimmer and fluency were measured in these three speech samples performed with DBS stimulation on and off.

RESULTS

During subcortical stimulation, spontaneous excerpts were less intelligible than repeated excerpts. F0 and HNR were higher and shimmer was decreased in repetition and stimulation. Articulatory dysfluencies were increased for spontaneous speech and during stimulation in all three speech samples.

CONCLUSION

Deep brain stimulation disrupts fluency and improves voice in spontaneous speech, reflecting an inverse influence of subcortical systems on articulatory posturing and laryngeal mechanisms. Better voice and less dysfluency in repetition may occur because an external model reduces the speech planning burden, as seen for gait and arm reach. These orthogonal results for fluency versus phonatory competence may account for ambivalent reports from dysarthric speakers and reveal the complexity of subcortical control of motor speech.

Evaluation, treatment, and analysis of a rare case of motor speech systems dyscoordination syndrome

This report describes an unusual presentation of a voice disorder arising from inability to coordinate the three components of motor speech: respiration, phonation, and articulation. These systems were individually intact, as demonstrated by laryngoscopy, motor speech examination, and treatment methods achieving success under controlled conditions. Following initial programming of his deep brain stimulation (DBS) device, a 62-year-old male, diagnosed with Parkinson's disease (PD) 14 years previously, abruptly experienced a vocal disorder characterized by pressed, very low frequency creaky voice produced on held breath. Evaluation and therapy sessions revealed intact respiration, phonation, and articulation as component systems of motor speech, while indicating a severe deficit in coordinating these systems for articulated speech. Performance varied with mode of vocal production. Vowel prolongation and singing were normal in contrast to severe impairment when respiration and phonation were integrated with articulated speech. A listening study utilizing speech samples from five spoken modes-conversation, repetition, formulaic expressions, continuously phonated material and singing, yielded higher intelligibility on sung and continuously phonated phrases, confirming clinical impressions. Acoustic measures of fundamental frequency, vowel quality (harmonic-to-noise ratios) and duration supported the intelligibility results. Repetition and conversation were similarly impaired, suggesting that the disability was not attributable to the basal ganglia. This case reveals the role of higher order management of respiration, articulation, and voice for speech and describes a successful treatment utilizing breath control.

Respiratory and Laryngeal Changes With Vocal Loading in Younger and Older Individuals

PURPOSE

The objective of the current study was to investigate the effects of age and vocal loading on the respiratory and laryngeal systems.

METHOD

Fourteen younger (M = 20 years) and 13 older (M = 75 years) healthy individuals participated in a 40-min vocal loading challenge in the presence of 70-dB background noise. Respiratory kinematic and laryngeal measurements were obtained before and after the challenge.

RESULTS

Following the loading challenge, participants in both groups reported greater speaking effort. Sound pressure level increased in the older group and decreased in the younger group after loading. Younger adults, but not older adults, used lower lung volume initiations and higher lung volume terminations after loading. Cepstral peak prominence increased with loading in both groups, but this change was of small magnitude and not clinically significant.

CONCLUSIONS

The negative effects of loading were observed in respiratory and laryngeal measures, although the pattern of changes differed across the groups. These data increase our knowledge of underlying respiratory and laryngeal physiological changes following a loading challenge and may reflect some of the physiologic mechanisms underlying vocal fatigue.

Internally Versus Externally Cued Speech in Parkinson's Disease and Cerebellar Disease

PURPOSE

The purpose of this study was to examine the effects of an internally versus externally cued speech task on perceived understandability and naturalness in speakers with Parkinson's disease (PD) and cerebellar disease (CD).

METHOD

Sentences extracted from a covertly recorded conversation (internally cued) were compared to the same sentences read aloud (externally cued) by speakers with PD and a clinical comparison group of speakers with CD. Experienced listeners rated the speech samples using a visual analog scale for the perceptual dimensions of understandability and naturalness.

RESULTS

Results suggest that experienced listeners rated the speech of participants with PD as significantly more natural and more understandable during the reading condition. Participants with CD were also rated as significantly more understandable during the reading condition, but ratings of naturalness did not differ between conversation and reading.

CONCLUSIONS

Speech tasks can have a pronounced impact on perceived speech patterns. For individuals with PD, both understandability and naturalness can improve during reading tasks versus conversational tasks. The speech benefits from reading may be attributed to several mechanisms, including possible improvement from an externally cued speech task. These findings have implications for speech task selection in evaluating individuals with dysarthria.

Longitudinal Changes in Speech Breathing in Older Adults with and without Parkinson's Disease

This longitudinal study examines changes to speech production and speech breathing in older adults with Parkinson's disease (PD) and older adults without PD. Eight participants with PD and eight age- and sex-matched older adults participated in two data collection sessions, separated by 3.7 years on average. Speech severity and speech rate increased for people with PD. Vital capacity decreased for both groups. Older adult control participants displayed significant increases in lung volume initiation and excursion and percent vital capacity expended per syllable. These changes allow older adults to utilize higher recoil pressures to generate subglottal pressure for speech production, potentially reducing work of breathing. Participants with PD displayed significant decreases in lung volume initiation and termination. Thus, unlike older adults, people with PD exert more expiratory muscle pressure during speech production, leading to increased effort. Speech-language pathologists need to consider direct treatment of respiratory patterns for speech to reduce effort and fatigue.