Voice onset time in Parkinson disease

Lie Detection Based on Acoustic Analysis

PURPOSE

Acoustic lie detection, prized for its covert nature and capability for remote processing, has spurred growing interest in acoustic features that can reliably aid in lie detection. In this study, the aim was to construct an acoustic polygraph based on a variety of phonetic and acoustic features rather than on electrodermal, cardiovascular, and respiratory values.

METHODS

Sixty-two participants from the University of Science and Technology of China, aged 18-30 years old, were involved in the mock crime experiment and were randomly assigned to the innocent and guilty groups. We collected 31 deceptive and truthful audios to analyze the performance of voice onset time (VOT) in lie detection.

RESULTS

Our findings revealed that VOT performed well in lie detection. Both the average sensitivity and specificity of the area under the curve are 0.888, and its lower and upper confidence limit are up to 0.803 and 0.973 respectively at the 95% confidence level. Although the other acoustic features had a lower reference value, they also provided a general trend in the judgment of lie detection.

CONCLUSIONS

Our results suggested that some acoustic features can be effectively used as aids to lie detection. Through a similar approach, we will explore more acoustic and phonetic features that contribute to detecting lies in the future.

Acoustic assessment in mandarin-speaking Parkinson's disease patients and disease progression monitoring and brain impairment within the speech subsystem

Approximately 90% of Parkinson's patients (PD) suffer from dysarthria. However, there is currently a lack of research on acoustic measurements and speech impairment patterns among Mandarin-speaking individuals with PD. This study aims to assess the diagnosis and disease monitoring possibility in Mandarin-speaking PD patients through the recommended speech paradigm for non-tonal languages, and to explore the anatomical and functional substrates. We examined total of 160 native Mandarin-speaking Chinese participants consisting of 80 PD patients, 40 healthy controls (HC), and 40 MRI controls. We screened the optimal acoustic metric combination for PD diagnosis. Finally, we used the objective metrics to predict the patient's motor status using the Naïve Bayes model and analyzed the correlations between cortical thickness, subcortical volumes, functional connectivity, and network properties. Comprehensive acoustic screening based on prosodic, articulation, and phonation abnormalities allows differentiation between HC and PD with an area under the curve of 0.931. Patients with slowed reading exhibited atrophy of the fusiform gyrus (FDR p = 0.010, R = 0.391), reduced functional connectivity between the fusiform gyrus and motor cortex, and increased nodal local efficiency (NLE) and nodal efficiency (NE) in bilateral pallidum. Patients with prolonged pauses demonstrated atrophy in the left hippocampus, along with decreased NLE and NE. The acoustic assessment in Mandarin proves effective in diagnosis and disease monitoring for Mandarin-speaking PD patients, generalizing standardized acoustic guidelines beyond non-tonal languages. The speech impairment in Mandarin-speaking PD patients not only involves motor aspects of speech but also encompasses the cognitive processes underlying language generation.

A neurocomputational view of the effects of Parkinson's disease on speech production

The purpose of this article is to review the scientific literature concerning speech in Parkinson's disease (PD) with reference to the DIVA/GODIVA neurocomputational modeling framework. Within this theoretical view, the basal ganglia (BG) contribute to several different aspects of speech motor learning and execution. First, the BG are posited to play a role in the initiation and scaling of speech movements. Within the DIVA/GODIVA framework, initiation and scaling are carried out by initiation map nodes in the supplementary motor area acting in concert with the BG. Reduced support of the initiation map from the BG in PD would result in reduced movement intensity as well as susceptibility to early termination of movement. A second proposed role concerns the learning of common speech sequences, such as phoneme sequences comprising words; this view receives support from the animal literature as well as studies identifying speech sequence learning deficits in PD. Third, the BG may play a role in the temporary buffering and sequencing of longer speech utterances such as phrases during conversational speech. Although the literature does not support a critical role for the BG in representing sequence order (since incorrectly ordered speech is not characteristic of PD), the BG are posited to contribute to the scaling of individual movements in the sequence, including increasing movement intensity for emphatic stress on key words. Therapeutic interventions for PD have inconsistent effects on speech. In contrast to dopaminergic treatments, which typically either leave speech unchanged or lead to minor improvements, deep brain stimulation (DBS) can degrade speech in some cases and improve it in others. However, cases of degradation may be due to unintended stimulation of efferent motor projections to the speech articulators. Findings of spared speech after bilateral pallidotomy appear to indicate that any role played by the BG in adult speech must be supplementary rather than mandatory, with the sequential order of well-learned sequences apparently represented elsewhere (e.g., in cortico-cortical projections).

Exploring the impact of type II diabetes mellitus on voice quality

PURPOSE

This cross-sectional study aimed to investigate the potential of voice analysis as a prescreening tool for type II diabetes mellitus (T2DM) by examining the differences in voice recordings between non-diabetic and T2DM participants.

METHODS

60 participants diagnosed as non-diabetic (n = 30) or T2DM (n = 30) were recruited on the basis of specific inclusion and exclusion criteria in Iran between February 2020 and September 2023. Participants were matched according to their year of birth and then placed into six age categories. Using the WhatsApp application, participants recorded the translated versions of speech elicitation tasks. Seven acoustic features [fundamental frequency, jitter, shimmer, harmonic-to-noise ratio (HNR), cepstral peak prominence (CPP), voice onset time (VOT), and formant (F1-F2)] were extracted from each recording and analyzed using Praat software. Data was analyzed with Kolmogorov-Smirnov, two-way ANOVA, post hoc Tukey, binary logistic regression, and student t tests.

RESULTS

The comparison between groups showed significant differences in fundamental frequency, jitter, shimmer, CPP, and HNR (p < 0.05), while there were no significant differences in formant and VOT (p > 0.05). Binary logistic regression showed that shimmer was the most significant predictor of the disease group. There was also a significant difference between diabetes status and age, in the case of CPP.

CONCLUSIONS

Participants with type II diabetes exhibited significant vocal variations compared to non-diabetic controls.

Effects of Deep-Brain Stimulation on Speech: Perceptual and Acoustic Data

PURPOSE

This study examined speech changes induced by deep-brain stimulation (DBS) in speakers with Parkinson's disease (PD) using a set of auditory-perceptual and acoustic measures.

METHOD

Speech recordings from nine speakers with PD and DBS were compared between DBS-On and DBS-Off conditions using auditory-perceptual and acoustic analyses. Auditory-perceptual ratings included voice quality, articulation precision, prosody, speech intelligibility, and listening effort obtained from 44 listeners. Acoustic measures were made for voicing proportion, second formant frequency slope, vowel dispersion, articulation rate, and range of fundamental frequency and intensity.

RESULTS

No significant changes were found between DBS-On and DBS-Off for the five perceptual ratings. Four of six acoustic measures revealed significant differences between the two conditions. While articulation rate and acoustic vowel dispersion increased, voicing proportion and intensity range decreased from the DBS-Off to DBS-On condition. However, a visual examination of the data indicated that the statistical significance was mostly driven by a small number of participants, while the majority did not show a consistent pattern of such changes.

CONCLUSIONS

Our data, in general, indicate no-to-minimal changes in speech production ensued from DBS stimulation. The findings are discussed with a focus on large interspeaker variability in PD in terms of their speech characteristics and the potential effects of DBS on speech.

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.

Effects of a Concurrent Working Memory Task on Speech Acoustics in Parkinson's Disease

PURPOSE

The purpose of this study was to determine the effect of a concurrent working memory task on acoustic measures of speech in individuals with Parkinson's disease (PD).

METHOD

Individuals with PD and age- and sex-matched controls performed a speaking task with and without a Stroop-like concurrent working memory task. Cepstral peak prominence, low-to-high spectral energy ratio, fundamental frequency (fo) standard deviation, articulation rate, pause duration, articulatory-acoustic vowel space, relative fo, mean voice onset time (VOT), and VOT variability were calculated for each condition. Mixed-model analyses of variance were performed to determine the effects of group, condition (presence of the concurrent working memory task), and their interaction on the acoustic measures.

RESULTS

All measures except for VOT variability, mean pause duration, and relative fo offset differed between people with and without PD. Cepstral peak prominence, articulation rate, and relative fo offset differed as a function of condition. However, no measures indicated disparate effects of condition as a function of group.

CONCLUSION

Although differentially impactful on limb motor function in PD, here a concurrent working memory task was not found to be differentially disruptive to speech acoustics in PD.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.24759648.

Consonant articulation acoustics and intelligibility in Swedish speakers with Parkinson's disease: a pilot study

Imprecise consonant articulation is common in speakers with Parkinson's disease and can affect intelligibility. The research on the relationship between acoustic speech measures and intelligibility in Parkinson's disease is limited, and most of the research has been conducted on English. This pilot study investigated aspects of consonant articulation acoustics in eleven Swedish speakers with Parkinson's disease and six neurologically healthy persons. The focus of the study was on consonant cluster production, articulatory motion rate and variation, and voice onset time, and how these acoustic features correlate with speech intelligibility. Among the measures in the present study, typicality ratings of heterorganic consonant clusters /spr/ and /skr/ had the strongest correlations with intelligibility. Measures based on syllable repetition, such as repetition rate and voice onset time, showed varying results with weak to moderate correlations with intelligibility. One conclusion is that some acoustic measures may be more sensitive than others to the impact of the underlying sensory-motor impairment and dysarthria on speech production and intelligibility in speakers with Parkinson's disease. Some aspects of articulation appear to be equally demanding in terms of acoustic realisation for elderly healthy speakers and for speakers with Parkinson's disease, such as sequential motion rate measures. Clinically, this would imply that for the purpose of detecting signs of disordered speech motor control, choosing measures with less variation among older speakers without articulation impairment would lead to more robust results.

VOT y VOT ratio en hispanohablantes con Enfermedad de Parkinson

El Voice Onset Time (VOT) es una medida acústica que hace referencia a la diferencia entre el tiempo de la liberación de la oclusión y el inicio de la vibración de las cuerdas vocales en los sonidos oclusivos; el VOT ratio (VOTr), por su parte, se refiere a la relación entre el VOT y la duración de la sílaba que busca modelar el efecto de la velocidad del habla sobre el VOT. Ambas medidas han sido estudiadas en hablantes con Enfermedad de Parkinson (EP) en tareas de habla experimentales, pero existen pocos trabajos en personas con EP que sean hispanohablantes y en el contexto de habla conectada. En este estudio se investigó el comportamiento del VOT y VOTr en habla conectada en hispanohablantes colombianos con EP. Mediante el software Praat se calculó el VOT y VOTr de los sonidos /p, b, t, d, k, g/ en grabaciones tomadas del corpus PC-GITA que correspondían a 50 personas con EP y 50 sin EP pareadas por edad y sexo. Se encontró que, con algunas variaciones, el VOT y el VOTr en habla conectada se comportan de manera similar entre sí y respecto a otros contextos de análisis previamente estudiados; comparado con el grupo control, se hallaron diferencias en las personas con EP, pero estas solamente fueron significativas en el VOT y VOTr de /p/, que fue más largo para las mujeres con EP(p < .05) así como en el VOT y VOTr de /d/ para ambos sexos con EP, pues fueron menores(p ≤ .05). Las diferencias relacionadas con el sexo solamente estuvieron entre hombres y mujeres con EP en el VOT de /p/, que fue más largo en las mujeres (p < .05). Esta evidencia podría indicar que en español, en habla conectada, el VOT y el VOTr son igual de sensibles a los cambios en el VOT asociados a la EP y al parecer el sexo no tiene un efecto significativo sobre ellas.

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

PURPOSE

The aim of this study was to conduct a scoping review of research on oral and laryngeal diadochokinesis (DDK) in children and adults, either typically developing/developed or with a clinical diagnosis.

METHOD

Searches were conducted with PubMed/MEDLINE, Google Scholar, CINAHL, and legacy sources in retrieved articles. Search terms included the following: DDK, alternating motion rate, maximum repetition rate, sequential motion rate, and syllable repetition rate.

RESULTS

Three hundred sixty articles were retrieved and included in the review. Data source tables for children and adults list the number and ages of study participants, DDK task, and language(s) spoken. Cross-sectional data for typically developing children and typically developed adults are compiled for the monosyllables /pʌ/, /tʌ/, and /kʌ/; the trisyllable /pʌtʌkʌ/; and laryngeal DDK. In addition, DDK results are summarized for 26 disorders or conditions.

DISCUSSION

A growing number of multidisciplinary reports on DDK affirm its role in clinical practice and research across the world. Atypical DDK is not a well-defined singular entity but rather a label for a collection of disturbances associated with diverse etiologies, including motoric, structural, sensory, and cognitive. The clinical value of DDK can be optimized by consideration of task parameters, analysis method, and population of interest.

Speech Rate Mediated Vowel and Stop Voicing Distinctiveness in Parkinson's Disease

Purpose The purpose of this study was to quantify changes in acoustic distinctiveness in two groups of talkers with Parkinson's disease as they modify across a wide range of speaking rates. Method People with Parkinson's disease with and without deep brain stimulation and older healthy controls read 24 carrier phrases at different speech rates. Target nonsense words in the carrier phrases were designed to elicit stop consonants and corner vowels. Participants spoke at seven self-selected speech rates from very slow to very fast, elicited via magnitude production. Speech rate was measured in absolute words per minute and as a proportion of each talker's habitual rate. Measures of segmental distinctiveness included a temporal consonant measure, namely, voice onset time, and a spectral vowel measure, namely, vowel articulation index. Results All talkers successfully modified their rate of speech from slow to fast. Talkers with Parkinson's disease and deep brain stimulation demonstrated greater baseline speech impairment and produced smaller proportional changes at the fast end of the continuum. Increasingly slower speaking rates were associated with increased temporal contrasts (voice onset time) but not spectral contrasts (vowel articulation). Faster speech was associated with decreased contrasts in both domains. Talkers with deep brain stimulation demonstrated more aberrant productions across all speaking rates. Conclusions Findings suggest that temporal and spectral segmental distinctiveness are asymmetrically affected by speaking rate modifications in Parkinson's disease. Talkers with deep brain stimulation warrant further investigation with regard to speech changes they make as they adjust their speaking rate.

Adults with a history of recreational cannabis use have altered speech production

Stereotypical depictions of speech in cannabis users often suggest slow, laboured output, yet objective evidence supporting this assumption is extremely limited. We know that depressants or hallucinogenic drugs such as cannabis can cause acute changes in communication and speech rate, but the long-lasting effects of cannabis use on speech are not well described. The aim of this study was to investigate speech in individuals with a history of recreational cannabis use compared to non-drug-using healthy controls. Speech samples were collected from a carefully described cohort of 31 adults with a history of cannabis use (but not use of illicit stimulant drugs) and 40 non-drug-using controls. Subjects completed simple and complex speech tasks including a monologue, a sustained vowel, saying the days of the week, and reading a phonetically balanced passage. Audio samples were analysed objectively using acoustic analysis for measures of timing, vocal control, and quality. Subtle differences in speech timing, vocal effort, and voice quality may exist between cannabis and control groups, however data remain equivocal. After controlling for lifetime alcohol and tobacco use and applying a false discovery rate, only spectral tilt (vocal effort and intensity) differed between groups and appeared to change in line with duration of abstinence from cannabis use. Differences between groups may reflect longer term changes to the underlying neural control of speech. Our digital analysis of speech shows there may be a signal differentiating individuals with a history of recreational cannabis use from healthy controls, in line with similar findings from gait and hand function studies.

Guidelines for Speech Recording and Acoustic Analyses in Dysarthrias of Movement Disorders

Most patients with movement disorders have speech impairments resulting from sensorimotor abnormalities that affect phonatory, articulatory, and prosodic speech subsystems. There is widespread cross-discipline use of speech recordings for diagnostic and research purposes, despite which there are no specific guidelines for a standardized method. This review aims to combine the specific clinical presentations of patients with movement disorders, existing acoustic assessment protocols, and technological advances in capturing speech to provide a basis for future research in this field and to improve the consistency of clinical assessments. We considered 3 areas: the recording environment (room, seating, background noise), the recording process (instrumentation, vocal tasks, elicitation of speech samples), and the acoustic outcome data. Four vocal tasks, namely, sustained vowel, sequential and alternating motion rates, reading passage, and monologues, are integral aspects of motor speech assessment. Fourteen acoustic vocal speech features, including their hypothesized pathomechanisms with regard to typical occurrences in hypokinetic or hyperkinetic dysarthria, are hereby recommended for quantitative exploratory analysis. Using these acoustic features and experimental speech data, we demonstrated that the hyperkinetic dysarthria group had more affected speech dimensions compared with the healthy controls than had the hypokinetic speakers. Several contrasting speech patterns between both dysarthrias were also found. This article is the first attempt to provide initial recommendations for a standardized way of recording the voice and speech of patients with hypokinetic or hyperkinetic dysarthria; thus allowing clinicians and researchers to reliably collect, acoustically analyze, and compare vocal data across different centers and patient cohorts. © 2020 International Parkinson and Movement Disorder Society.

Evaluation of the voice onset time in Turkish-Speaking schoolchildren

OBJECTIVES

To determine the voice onset time (VOT) values of Turkish speaking schoolchildren and to evaluate the effect of gender, age and vowel height on VOT values in this age group.

METHODS

One hundred and twenty native Turkish children between the ages of 7-11 years were included in the study. All children were divided into 4 age groups: Group I 7.0 to 7 years, 11 months; Group II 8.0 to 8 years, 11 months; Group III 9.0 to 9 years, 11 months; and Group IV 10.0 to 10 years, 11 months. The six Turkish plosive sounds (/p/,/b/,/t/,/d/,/k/,/g/) and the eight Turkish vowel sounds (/a/,/e/,/ɯ/,/i/,/o/,/oe/,/u/,/y/) were compiled into 48 different syllables, such as/pa/,/be/,/ti/, and/ko/. The syllables were repeated three times and were recorded by Behringer C-1 studio condenser microphone. Records were analysed by Praat software. The VOT values was established by measuring the time between temporary plosion of the pause and the onset of vocal fold vibration.

RESULTS

The mean voice onset time values of the voiced and voiceless plosive sounds of the groups were analysed with One Way ANOVA test. There was no statistically significant difference between the groups (p > 0.05). The VOT values of voiceless plosive sounds in all groups were established as positive, and VOT values of voiced plosive sounds were found to be negative. Mean VOT values according to gender was analysed by Independent Samples t-test. A significant difference was found between genders in voiced (/b/,/d/,/g/) plosive sounds and in the/t/sound among the voiceless plosive sounds (p < 0.05). The difference between the heights of vowels and VOT were analysed by one-way ANOVA test. A significant difference was observed between the height of the following vowel and the voiceless plosives/p/,/t/,/k/and voiced plosive/b/(p < 0.05).

CONCLUSIONS

The VOT values of voiceless plosive sounds in Turkishspeaking schoolchildren were positive and the VOT values of their voiced plosive sounds were found negative. It was established that the height of the following vowel increases the VOT values of voiceless plosive sounds and has a variable effect on voiced plosive sounds.

Immediate Effect of the Finger-Kazoo Technique Associated with Glissandos in the Voice of Individuals with Parkinson's Disease

OBJECTIVE

To verify the immediate effect of the Finger Kazoo technique associated with glissandos in the voice of individuals with Parkinson's disease.

METHOD

Thirty subjects with Parkinson's Disease comprised of 15 men and 15 women with a mean age of 63.8 years (± 6.88) and mean time of diagnosis of 97.33 (± 63.53) months, all with preserved cognition. The subjects' voice range profile (VRP), speech range profile (SRP), and the maximum phonation time were assessed, before and after applying the Finger Kazoo technique associated with ascending and descending glissando. After the technique, a vocal satisfaction questionnaire was completed.

RESULTS

After the applied technique there was an increase in the minimum and maximum fundamental frequency recorded respectively in the SRP and in the VRP; there was an increase in the vocal range (measured in Hertz and semitones) of the women, recorded in the VRP; in the male population, there was an increase in maximum phonation time. A higher percentage of positive references to vocal improvement was observed after the exercise.

CONCLUSION

In patients with Parkinson's Disease, the Finger Kazoo with glissando technique promoted an increase in the minimum fundamental frequency of the SRP and in the vocal extensions of women, as well as increasing the maximum phonatory time of men. In addition, patients reported satisfaction with the use of the technique and its results.

Voice Onset Time in Individuals With Hyperfunctional Voice Disorders: Evidence for Disordered Vocal Motor Control

Purpose This study examined vocal hyperfunction (VH) using voice onset time (VOT). We hypothesized that speakers with VH would produce shorter VOTs, indicating increased laryngeal tension, and more variable VOTs, indicating disordered vocal motor control. Method We enrolled 32 adult women with VH (aged 20-74 years) and 32 age- and sex-matched controls. All were speakers of American English. Participants produced vowel-consonant-vowel combinations that varied by vowel (ɑ/u) and plosive (p/b, t/d, k/g). VOT-measured at the release of the plosive to the initiation of voicing-was averaged over three repetitions of each vowel-consonant-vowel combination. The coefficient of variation (CoV), a measure of VOT variability, was also computed for each combination. Results The mean VOTs were not significantly different between the two groups; however, the CoVs were significantly greater in speakers with VH compared to controls. Voiceless CoV values were moderately correlated with clinical ratings of dysphonia (r = .58) in speakers with VH. Conclusion Speakers with VH exhibited greater variability in phonemic voicing targets compared to vocally healthy speakers, supporting the hypothesis for disordered vocal motor control in VH. We suggest future work incorporate VOT measures when assessing auditory discrimination and auditory-motor integration deficits in VH.

Technology-based assessment of motor and nonmotor phenomena in Parkinson disease

INTRODUCTION

The increasing development and availability of portable and wearable technologies is rapidly expanding the field of technology-based objective measures (TOMs) in neurological disorders, including Parkinson disease (PD). Substantial challenges remain in the recognition of disease phenomena relevant to patients and clinicians, as well as in the identification of the most appropriate devices to carry out these measurements. Areas covered: The authors systematically reviewed PubMed for studies employing technology as outcome measures in the assessment of PD-associated motor and nonmotor abnormalities. Expert commentary: TOMs minimize intra- and inter-rater variability in clinical assessments of motor and nonmotor phenomena in PD, improving the accuracy of clinical endpoints. Critical unmet needs for the integration of TOMs into clinical and research practice are the identification and validation of relevant endpoints for individual patients, the capture of motor and nonmotor activities from an ecologically valid environment, the integration of various sensor data into an open-access, common-language platforms, and the definition of a regulatory pathway for approval of TOMs. The current lack of multidomain, multisensor, smart technologies to measure in real time a wide scope of relevant changes remain a significant limitation for the integration of technology into the assessment of PD motor and nonmotor functional disability.

A Diadochokinesis-based expert system considering articulatory features of plosive consonants for early detection of Parkinson's disease

BACKGROUND AND OBJECTIVE

A new expert system is proposed to discriminate healthy people from people with Parkinson's Disease (PD) in early stages by using Diadochokinesis tests.

METHODS

The system is based on temporal and spectral features extracted from the Voice Onset Time (VOT) segments of /ka/ syllables, whose boundaries are delimited by a novel algorithm. For comparison purposes, the approach is applied also to /pa/ and /ta/ syllables. In order to develop and validate the system, a voice recording database composed of 27 individuals diagnosed with PD and 27 healthy controls has been collected. This database reflects an average disease stage of 1.85 ± 0.55 according to Hoehn and Yahr scale. System design is based on feature extraction, feature selection and Support Vector Machine learning.

RESULTS

The novel VOT algorithm, based on a simple and computationally efficient approach, demonstrates accurate estimation of VOT boundaries on /ka/ syllables for both healthy and PD-affected speakers. The PD detection approach based on /k/ plosive consonant achieves the highest discrimination capability (92.2% using 10-fold cross-validation and 94.4% in the case of leave-one-out method) in comparison to the corresponding versions based on the other two plosives (/p/ and /t/).

CONCLUSION

A high accuracy has been obtained on a database with a lower average disease stage than previous articulatory databases presented in the literature.

Voicing contrast of stop consonant production in the speech of individuals with Parkinson disease ON and OFF dopaminergic medication

The aims of this study were to: 1) compare voicing contrast in speakers with Parkinson disease (PD) and healthy controls by comparing the separation of voice onset time (VOT) distributions of voiced and voiceless stop consonants and 2) to determine whether the administration of dopaminergic medication affected VOT separation in speakers with PD. Data from a previous study by Fisher and Goberman (2010) were used to compare the VOT measures obtained from a group of speakers with PD with both ON and OFF medication, and a group of healthy controls. Supplementing the previous findings, the current analysis revealed that individuals with PD exhibited significantly less contrast between voiced and voiceless VOT than that observed in healthy speakers. Medication administration did not affect VOT contrast as no differences in VOT separation were observed between the ON and OFF medication states.

A Cross-Language Study of Acoustic Predictors of Speech Intelligibility in Individuals With Parkinson's Disease

PURPOSE

The present study aimed to compare acoustic models of speech intelligibility in individuals with the same disease (Parkinson's disease [PD]) and presumably similar underlying neuropathologies but with different native languages (American English [AE] and Korean).

METHOD

A total of 48 speakers from the 4 speaker groups (AE speakers with PD, Korean speakers with PD, healthy English speakers, and healthy Korean speakers) were asked to read a paragraph in their native languages. Four acoustic variables were analyzed: acoustic vowel space, voice onset time contrast scores, normalized pairwise variability index, and articulation rate. Speech intelligibility scores were obtained from scaled estimates of sentences extracted from the paragraph.

RESULTS

The findings indicated that the multiple regression models of speech intelligibility were different in Korean and AE, even with the same set of predictor variables and with speakers matched on speech intelligibility across languages. Analysis of the descriptive data for the acoustic variables showed the expected compression of the vowel space in speakers with PD in both languages, lower normalized pairwise variability index scores in Korean compared with AE, and no differences within or across language in articulation rate.

CONCLUSIONS

The results indicate that the basis of an intelligibility deficit in dysarthria is likely to depend on the native language of the speaker and listener. Additional research is required to explore other potential predictor variables, as well as additional language comparisons to pursue cross-linguistic considerations in classification and diagnosis of dysarthria types.

Group climate in the voice therapy of patients with Parkinson's Disease

Purpose

To verify the impact that group dynamics and coaching strategies have on the PD patients voice, speech and communication, as well as the group climate.

Methods

16 individuals with mild to moderate dysarthria due to the PD were divided into two groups: the CG (8 patients), submitted to traditional therapy with 12 regular therapy sessions plus 4 additional support sessions; and the EG (8 patients), submitted to traditional therapy with 12 regular therapy sessions plus 4 sessions with group dynamics and coaching strategies. The Living with Dysarthria questionnaire (LwD), the self-evaluation of voice, speech and communication, and the perceptual-auditory analysis of the vocal quality were assess in 3 moments: pre-traditional therapy (pre); post-traditional therapy (post 1); and post support sessions/coaching strategies (post 2); in post 1 and post 2 moments, the Group Climate Questionnaire (GCQ) was also applied.

Results

CG and EG showed an improvement in the LwD from pre to post 1 and post 2 moments. Voice self-evaluation was better for the EG - when pre was compared with post 2 and when post 1 was compared with post 2 - ranging from regular to very good; both groups presented improvement in the communication self-evaluation. The perceptual-auditory evaluation of the vocal quality was better for the EG in the post 1 moment. No difference was found for the GCQ; however, the EG presented lower avoidance scores in post 2.

Conclusion

All patients showed improvement in the voice, speech and communication self-evaluation; EG showed lower avoidance scores, creating a more collaborative and propitious environment for speech therapy.

Exploring risk factors for stuttering development in Parkinson disease after deep brain stimulation

BACKGROUND

Stuttering is a speech disorder with disruption of verbal fluency, occasionally present in Parkinson's disease (PD). PD co-incident stuttering may either worsen or improve after Deep Brain Stimulation (DBS).

METHODS

Sixteen out of 453 PD patients (3.5%) exhibited stuttering after DBS (PD-S) and were compared with a group of patients without stuttering (PD-NS) using non-parametric statistics.

RESULTS

After DBS, stuttering worsened in 3 out of 4 patients with co-incidental stuttering. Most PD-S underwent subthalamic (STN) DBS, but 4 were implanted in the globus pallidus (GPi). Nine out of 16 PD-S (56.3%) reported a positive familial history for stuttering compared to none of the PD-NS. PD-S were mainly male (81.3%) with slight worse motor features compared to PD-NS.

CONCLUSION

Herein, we describe a group of PD patients developing stuttering after DBS and report the presence of a positive familial history for stuttering as the most relevant risk factor, suggesting a possible underlying genetic cause. The fact that stuttering occurred after either STN or GPi DBS is an argument against the impact of medication reduction on stuttering.

Automated analysis of connected speech reveals early biomarkers of Parkinson's disease in patients with rapid eye movement sleep behaviour disorder

For generations, the evaluation of speech abnormalities in neurodegenerative disorders such as Parkinson's disease (PD) has been limited to perceptual tests or user-controlled laboratory analysis based upon rather small samples of human vocalizations. Our study introduces a fully automated method that yields significant features related to respiratory deficits, dysphonia, imprecise articulation and dysrhythmia from acoustic microphone data of natural connected speech for predicting early and distinctive patterns of neurodegeneration. We compared speech recordings of 50 subjects with rapid eye movement sleep behaviour disorder (RBD), 30 newly diagnosed, untreated PD patients and 50 healthy controls, and showed that subliminal parkinsonian speech deficits can be reliably captured even in RBD patients, which are at high risk of developing PD or other synucleinopathies. Thus, automated vocal analysis should soon be able to contribute to screening and diagnostic procedures for prodromal parkinsonian neurodegeneration in natural environments.

Distinct patterns of imprecise consonant articulation among Parkinson's disease, progressive supranuclear palsy and multiple system atrophy

Distinct speech characteristics that may aid in differentiation between Parkinson's disease (PD), progressive supranuclear palsy (PSP) and multiple system atrophy (MSA) remain tremendously under-explored. Here, the patterns and degree of consonant articulation deficits across voiced and voiceless stop plosives in 16 PD, 16 PSP, 16 MSA and 16 healthy control speakers were evaluated using acoustic and perceptual methods. Imprecise consonant articulation was observed across all Parkinsonian groups. Voice onset time of voiceless plosives was more prolonged in both PSP and MSA compared to PD, presumably due to greater severity of dysarthria and slower articulation rate. Voice onset time of voiced plosives was significantly shorter only in MSA, likely as a consequence of damage to cerebellar structures. In agreement with the reduction of pre-voicing, MSA manifested increased number of voiced plosives misclassified as voiceless at perceptual evaluation. Timing of articulatory movements may provide important clues about the pathophysiology of underlying disease.

The effect of increased vocal intensity on interarticulator timing in speakers with Parkinson’s disease: a preliminary analysis

PURPOSE

The purpose of the current study was to investigate the effect of increased vocal intensity on interarticulator timing in individuals with Parkinson's disease (PD).

METHODS

Ten individuals with mild to moderate hypophonia, secondary to PD, were selected for study. Over an 8-week treatment period, multi-talker babble noise was presented monaurally to the individuals with PD during everyday communication contexts to elicit increased vocal intensity (Lombard effect). Outcome measures included sound pressure level (SPL), voice onset time (VOT), VOT ratio, percent voicing, and speech intelligibility.

RESULTS

Group and individual participant responses to the treatment are reported and discussed. Speakers with PD were shown to significantly increase SPL in response to treatment. Six of the 10 speakers showed improved temporal coordination between the laryngeal and supralaryngeal mechanisms (interarticulator timing) in response to treatment. Four of the 10 speakers, however, showed reduced laryngeal–supralaryngeal timing at the end of treatment. Group speech intelligibility scores were significantly higher post-treatment as compared to pre-treatment.

CONCLUSIONS

Voice treatment during everyday communication resulted in improved temporal coordination across the laryngeal and supralaryngeal mechanisms for the majority of speakers with PD and made them easier to understand. Further investigations are planned to explore individual differences in response to treatment. The identification of speaker-specific voicing and devoicing strategies is consistent with the heterogeneous nature of PD.

LEARNING OUTCOMES

Readers will be able to: 1. Describe the speech and voice characteristics of individuals with Parkinson's disease. 2. Define the Lombard effect. 3. Describe acoustic measures of voice onset time and percent voicing. 4. Describe the effect of voice treatment on voice onset time and percent voicing in individuals with Parkinson's disease.

Presence of stop bursts and multiple bursts in individuals with Parkinson disease

Studies have reported that individuals with Parkinson Disease (PD) have imprecise articulation of stop consonants due to either slowness of articulators or decreased closure strength. The moment of release for stop consonants, called the burst, has been previously studied in individuals with PD and in other disorders. Multiple bursts (MBs) on the same stop consonant have been reported previously in some motor speech disorders, but no studies are known to have examined MBs in individuals with PD. The current study looked at the occurrences of bursts and MBs in initial stop consonants produced by nine individuals with PD (ON and OFF medication) and nine control speakers. Individuals with PD produced fewer overall bursts compared to control participants. In terms of place of articulation, individuals with PD primarily had loss of bursts in bilabial stops. In addition, individuals with PD had more MBs than control speakers, primarily in alveolars. Finally, no dopamine-related medication effects were found for occurrences of bursts or MBs in individuals with PD. Overall, the study provided evidence for loss of bursts and presence of MBs for stop consonants produced by individuals with PD.

A distinct variant of mixed dysarthria reflects parkinsonism and dystonia due to ephedrone abuse

A distinctive alteration of speech has been reported in patients suffering from ephedrone-induced parkinsonism. However, an objective assessment of dysarthria has not been performed in ephedrone users. We studied 28 young Caucasian men from Georgia with a previous history of ephedrone abuse and compared them to 25 age-matched healthy controls. Speech examination, brain MRI, and NNIPPS-Parkinson plus scale were performed in all patients. The accurate differential diagnosis of dysarthria subtypes was based on the quantitative acoustic analyses of 15 speech dimensions. We revealed a distinct variant of mixed dysarthria with a combination of hyperkinetic and hypokinetic components representing the altered motor programming of dystonia and bradykinesia in ephedrone-induced parkinsonism. According to acoustic analyses, all patients presented at least one affected speech dimension, whereas dysarthria was moderate in 43% and severe in 36% of patients. Further findings indicated relationships between motor subscores of dystonia and bradykinesia and speech components of loudness (r = -0.54, p < 0.01), articulation (r = 0.40, p < 0.05), and timing (r = -0.53, p < 0.01). In ephedrone-induced parkinsonism a prominent mixed hyperkinetic-hypokinetic dysarthria occurs that appears related to marked dystonia and bradykinesia and probably reflects manganese induced toxic and neurodegenerative damage to the globus pallidus internus and substantia nigra.

Phonetic imitation from an individual-difference perspective: subjective attitude, personality and "autistic" traits

Numerous studies have documented the phenomenon of phonetic imitation: the process by which the production patterns of an individual become more similar on some phonetic or acoustic dimension to those of her interlocutor. Though social factors have been suggested as a motivator for imitation, few studies has established a tight connection between language-external factors and a speaker's likelihood to imitate. The present study investigated the phenomenon of phonetic imitation using a within-subject design embedded in an individual-differences framework. Participants were administered a phonetic imitation task, which included two speech production tasks separated by a perceptual learning task, and a battery of measures assessing traits associated with Autism-Spectrum Condition, working memory, and personality. To examine the effects of subjective attitude on phonetic imitation, participants were randomly assigned to four experimental conditions, where the perceived sexual orientation of the narrator (homosexual vs. heterosexual) and the outcome (positive vs. negative) of the story depicted in the exposure materials differed. The extent of phonetic imitation by an individual is significantly modulated by the story outcome, as well as by the participant's subjective attitude toward the model talker, the participant's personality trait of openness and the autistic-like trait associated with attention switching.

Phonetic imitation from an individual-difference perspective: subjective attitude, personality and "autistic" traits

Numerous studies have documented the phenomenon of phonetic imitation: the process by which the production patterns of an individual become more similar on some phonetic or acoustic dimension to those of her interlocutor. Though social factors have been suggested as a motivator for imitation, few studies has established a tight connection between language-external factors and a speaker's likelihood to imitate. The present study investigated the phenomenon of phonetic imitation using a within-subject design embedded in an individual-differences framework. Participants were administered a phonetic imitation task, which included two speech production tasks separated by a perceptual learning task, and a battery of measures assessing traits associated with Autism-Spectrum Condition, working memory, and personality. To examine the effects of subjective attitude on phonetic imitation, participants were randomly assigned to four experimental conditions, where the perceived sexual orientation of the narrator (homosexual vs. heterosexual) and the outcome (positive vs. negative) of the story depicted in the exposure materials differed. The extent of phonetic imitation by an individual is significantly modulated by the story outcome, as well as by the participant's subjective attitude toward the model talker, the participant's personality trait of openness and the autistic-like trait associated with attention switching.

Analysis of voice and speech performance in Parkinson’s disease: a promising tool for the monitoring of disease progression and differential diagnosis

SUMMARY Abnormalities of voice and speech performance are common and are early features of Parkinson’s disease (PD) and other hypokinetic rigid syndromes, such as progressive supranuclear palsy. The typical pattern of dysarthria in PD is characterized by reduced loudness and pitch variability, often in combination with abnormalities of voice, articulatory insufficiencies and irregularity of speech rate and rhythm. Recent preliminary investigations on the progression of dysarthria in the course of PD, and on the comparison of dysarthria between PD and progressive supranuclear palsy speakers, justify the assumption that analysis of speech may become a helpful tool for the monitoring of presumably nondopaminergic features and disease progression in PD and for the differential diagnoses of different parkinsonian syndromes.

Nonmotor manifestations in Parkinson disease

BACKGROUND

Although the diagnosis of Parkinson disease (PD) still relies mainly on the appearance of its classical motor features of resting tremor, rigidity, bradykinesia, and postural instability, nonmotor manifestations in PD are now recognized as an integral component of this multisystem disorder.

REVIEW SUMMARY

Nonmotor complications in PD occur commonly. The current understanding of cognitive dysfunction; neuropsychiatric manifestations including psychosis, impulsive control, and compulsive disorders, depression, anxiety and apathy; autonomic complications such as hypotension, erectile dysfunction, and urinary complications; sleep disorders and other nonmotor manifestations are summarized in this review.

CONCLUSION

Nonmotor complications often carry a greater impact than motor features in PD. Therefore, heightened awareness and proper recognition of these features are critical in improving a Parkinson patient's quality of life.

Deep brain stimulation of caudal zona incerta and subthalamic nucleus in patients with Parkinson's disease: effects on diadochokinetic rate

The hypokinetic dysarthria observed in Parkinson's disease (PD) affects the range, speed, and accuracy of articulatory gestures in patients, reducing the perceived quality of speech acoustic output in continuous speech. Deep brain stimulation (DBS) of the subthalamic nucleus (STN-DBS) and of the caudal zona incerta (cZi-DBS) are current surgical treatment options for PD. This study aimed at investigating the outcome of STN-DBS (7 patients) and cZi-DBS (7 patients) in two articulatory diadochokinesis tasks (AMR and SMR) using measurements of articulation rate and quality of the plosive consonants (using the percent measurable VOT metric). The results indicate that patients receiving STN-DBS increased in articulation rate in the Stim-ON condition in the AMR task only, with no effect on production quality. Patients receiving cZi-DBS decreased in articulation rate in the Stim-ON condition and further showed a reduction in production quality. The data therefore suggest that cZi-DBS is more detrimental for extended articulatory movements than STN-DBS.

Quantitative acoustic measurements for characterization of speech and voice disorders in early untreated Parkinson's disease

An assessment of vocal impairment is presented for separating healthy people from persons with early untreated Parkinson's disease (PD). This study's main purpose was to (a) determine whether voice and speech disorder are present from early stages of PD before starting dopaminergic pharmacotherapy, (b) ascertain the specific characteristics of the PD-related vocal impairment, (c) identify PD-related acoustic signatures for the major part of traditional clinically used measurement methods with respect to their automatic assessment, and (d) design new automatic measurement methods of articulation. The varied speech data were collected from 46 Czech native speakers, 23 with PD. Subsequently, 19 representative measurements were pre-selected, and Wald sequential analysis was then applied to assess the efficiency of each measure and the extent of vocal impairment of each subject. It was found that measurement of the fundamental frequency variations applied to two selected tasks was the best method for separating healthy from PD subjects. On the basis of objective acoustic measures, statistical decision-making theory, and validation from practicing speech therapists, it has been demonstrated that 78% of early untreated PD subjects indicate some form of vocal impairment. The speech defects thus uncovered differ individually in various characteristics including phonation, articulation, and prosody.

Effects of soft palate implants on acoustic characteristics of voice and articulation

OBJECTIVE

To evaluate the effects of soft palate implants on voice and articulation.

STUDY DESIGN

Prospective case series.

METHODS

Male subjects (n=23) diagnosed with mild obstructive sleep apnea and/or habitual snoring underwent acoustic analysis with the Multidimensional Voice Program (Kay Multi-Speech Model 3700 Advanced Version; Kay Elemetrics [KayPentax], Lincoln Park, NJ) before and 8 weeks after insertion of palatal implants to determine the effects of soft palate implants on voice and articulation. Sustained vowels (/a/e/u/o/i/) and phonetically balanced carrier sentences were used for acoustic analyses. Parameters measured were fundamental frequency (F0), jitter, shimmer, noise-to-harmonics ratio, Voice Turbulence Index, Soft Phonation Index, degree of voiceless, degree of voice breaks and peak amplitude variation, first formant (F1) and second formant (F2) frequencies, and voice onset time (VOT). F1 and F2 for each vowel were determined using linear predictive analysis on a spectrogram. VOT was measured for the palatal consonant /k/ and the dental consonant /t/ on a wideband spectrogram from a carrier sentence segment that contained a syllable with a stop consonant.

RESULTS

No statistically significant difference was detected in F0, F1, F2, or other MDVP parameters before and after implantation. Average VOT values measured for /t/ were not significantly different. On the other hand, average VOT values of /k/ were found to be significantly shorter.

CONCLUSIONS

Implant insertion had no significant effect on MDVP parameters, F0, F1, or F2. On the other hand, articulation as a function of velar region seemed to be affected because VOT values of velar /k/ were changed.