Aerodynamic profiles of women with muscle tension dysphonia/aphonia

Self-reported voice difficulties in educational professionals during COVID-19 in Quebec: a cross-sectional mixed-methods study

Background: The health measures imposed by COVID-19 on workplaces created adverse communication settings. Our cross-sectional study aimed to document the nature and severity of the vocal difficulties experienced by educational professionals a few weeks after the implementation of health measures in schools and early childhood settings in Quebec, Canada while teaching in class.Methods: To this end, we conducted a self-report survey containing nine close-ended questions and one open-ended question regarding self-reported vocal difficulties and the implementation of health measures. The survey was answered by 194 educational professionals in October 2020.Results: Since the introduction of the health measures, respondents reported often or always: having difficulty making themselves heard (66.5%), needing to strain their voice (68.1%), having throat pain after work (38.1%), and being concerned about their vocal health (25.2%). 35.6% perceived that their voice changed moderately or a lot and 75.3% did not feel equipped to take care of their vocal health. Fisher's exact tests revealed the difficulties overall were more present in women (p < 0.05).Discussion: The qualitative analysis of open-ended question answers shows a circular process at play, where the vocal responses to the COVID-19-induced communication barriers contribute to creating more problematic communication settings, thus increasing the challenges for vocal health. Better equipping the professionals to take care of their vocal health by developing resources in their professional settings to help them face vocal challenges in both every day as well as extreme situations, should be a priority.

Is Surface Electromyography (sEMG) a Useful Tool in Identifying Muscle Tension Dysphonia? An Integrative Review of the Current Evidence

OBJECTIVE

This integrative review aims to determine the quality level of evidence on using surface electromyography (sEMG) as a diagnostic tool in identifying muscle tension dysphonia.

METHOD

Two independent reviewers used one search engine and five databases to identify sEMG studies published between January 1980 and December 2020, using a set of specified search terms related to muscle tension dysphonia. The selected articles were systematically evaluated by two independent raters using a modified critical appraisal of diagnostic evidence (m-CADE) form.

RESULTS

Nine articles that satisfied the inclusion criteria were selected from among 576 studies for evaluation. These nine studies showed varied methodological approaches in sEMG measurements, including electrode configuration and position, tasks used in sEMG data collection, outcome measure, and normalization procedures. Five studies showed relatively high m-CADE scores, which were indicative of "suggestive validity and compelling importance". Two studies were rated as "suggestive validity and importance", while two remaining studies were rated as "less suggestive or equivocal validity and importance".

CONCLUSIONS

The review found a moderate level of evidence that sEMG can be a potentially useful tool with diagnostic value in identifying muscle tension dysphonia. However, evidence is not yet available to determine the diagnostic accuracy of sEMG for muscle tension dysphonia. More studies are needed, and it is recommended that future studies involving sEMG and reference measurements should be undertaken using a blinding procedure in order to control any subjective biases. Details of the population that the sEMG has been tested on should be outlined clearly so that spectrum bias could be eliminated or minimized in the application process. Furthermore, it is suggested that a reliable and valid protocol in collecting sEMG data during speech should be developed to minimize the variability of sEMG measures in assessing muscle activities during speech.

The Effect of Adding Cricothyroid Visor Maneuver to Voice Facilitating Techniques on Improving Voice in Individuals With Primary Muscle Tension Dysphonia: A Pilot Randomized Clinical Trial

OBJECTIVES

The purpose of the present study was to examine the effect of adding a cricothyroid visor maneuver to conventional voice-facilitating techniques on voice quality and reported symptoms in patients with primary muscle tension dysphonia.

METHODS

This was a double-blind two parallel-group clinical trial in which 20 adult patients participated through convenience sampling. Participants were allocated to intervention (combined treatment) and control (conventional treatment) groups. The intervention was performed for both groups for five sessions, twice a week. The two groups were compared after the intervention for primary outcome measures including maximum phonation time, jitter, shimmer, harmonic-to-noise ratio, and consensus auditory-perceptual evaluation of voice, and for secondary outcome measures including the voice handicap index, the voice activity and participation profile, the voice-related pain scale, and the vocal tract discomfort scale.

RESULTS

Within-group primary outcome comparison showed that both groups showed significant improvement in maximum phonation time and consensus auditory-perceptual evaluation of voice indices after treatment. the between-group comparison showed that the maximum phonation time increased significantly in the intervention group after the treatment (P = 0.03) and the effect size was large (es = 1.05). within-group secondary outcome comparison showed that all indices improved significantly in both groups except for the voice-related pain scale frequency. The between-group comparison showed that except for voice-related pain scale frequency, the intervention group reported significantly more improvement in all other self-reporting indices with a large effect size.

CONCLUSIONS

The study showed that adding cricothyroid visor maneuver to conventional voice-facilitating techniques, compared to conventional treatment alone, resulted in a significant increase in maximum phonation time, reduction in pain and vocal tract discomfort, increase in activity and participation, and improvement in voice-handicapped index in primary muscle tension dysphonia patients. Therefore adding cricothyroid visor maneuver to other treatments can be an effective method in improving primary muscle tension dysphonia which needs more studies in the future.

Characterization of Primary Muscle Tension Dysphonia Using Acoustic and Aerodynamic Voice Metrics

OBJECTIVES/HYPOTHESIS

The objectives of this study were to (1) identify optimal clusters of 15 standard acoustic and aerodynamic voice metrics recommended by the American Speech-Language-Hearing Association (ASHA) to improve characterization of patients with primary muscle tension dysphonia (pMTD) and (2) identify combinations of these 15 metrics that could differentiate pMTD from other types of voice disorders.

STUDY DESIGN

Retrospective multiparametric METHODS: Random forest modeling, independent t-tests, logistic regression, and affinity propagation clustering were implemented on a retrospective dataset of 15 acoustic and aerodynamic metrics.

RESULTS

Ten percent of patients seen at the New York University (NYU) Voice Center over two years met the study criteria for pMTD (92 out of 983 patients), with 65 patients with pMTD and 701 of non-pMTD patients with complete data across all 15 acoustic and aerodynamic voice metrics. PCA plots and affinity propagation clustering demonstrated substantial overlap between the two groups on these parameters. The highest ranked parameters by level of importance with random forest models-(1) mean airflow during voicing (L/sec), (2) mean SPL during voicing (dB), (3) mean peak air pressure (cmH2O), (4) highest F0 (Hz), and (5) CPP mean vowel (dB)-accounted for only 65% of variance. T-tests showed three of these parameters-(1) CPP mean vowel (dB), (2) highest F0 (Hz), and (3) mean peak air pressure (cmH2O)-were statistically significant; however, the log2-fold change for each parameter was minimal.

CONCLUSION

Computational models and multivariate statistical testing on 15 acoustic and aerodynamic voice metrics were unable to adequately characterize pMTD and determine differences between the two groups (pMTD and non-pMTD). Further validation of these metrics is needed with voice elicitation tasks that target physiological challenges to the vocal system from baseline vocal acoustic and aerodynamic ouput. Future work should also place greater focus on validating metrics of physiological correlates (eg, neuromuscular processes, laryngeal-respiratory kinematics) across the vocal subsystems over traditional vocal output measures (eg, acoustics, aerodynamics) for patients with pMTD.

LEVEL OF EVIDENCE

II.

Methods of Measuring Laryngeal Muscle Tension in Patients with Muscle Tension Dysphonia: A Scoping Review

BACKGROUND

In clinical practice and research relating to Muscle Tension Dysphonia (MTD), several laryngeal muscle tension measurement methods are used to diagnose, to identify specific muscle strengths and deficits, and to measure therapeutic outcomes. The variety and reliability of available measurement methods presents challenges within diagnosis and treatment. The lack of methodical standardization presents a barrier to homogeneous practice in this area. There is a need for a comprehensive scoping review of laryngeal muscle tension measurement methods.

STUDY DESIGN

Scoping review.

OBJECTIVES

(1) To identify current methods of laryngeal muscle measurement which have been developed or tested with people with MTD; and (2) To identify the construct/s measured, reliability, validity, ability to detect change, efficiency and accessibility of identified methods.

METHOD

This scoping review was conducted using the Arksey and O'Malley framework. Studies were identified through searches of 4 major databases. The reviewer independently assessed titles, abstracts, and full-text articles.

RESULTS

Twenty seven papers published from 2000 to 2022 that satisfied the inclusion criteria were selected from 194 studies. The papers showed a variety of approaches with regards to the measurement of laryngeal activity and tension in subjects with MTD. Just over a quarter (25.9%) were reviews of the validity of assessment methods of MTD, including surface electromyography (sEMG), while 22.2% discussed surface electromyography as a measurement of muscle activity in subjects with MTD. 96.3% used a published methodological framework.

CONCLUSIONS

Assessment methods for Primary MTD are multifaceted, including patient history, laryngoscopic examination, and voice-related musculoskeletal features. Potential use of objective measurement methods, including sEMG, Real Time Elastosonography, Magnetic Resonance Imaging was noted. Due to variability in assessment methods and results, there is a need for greater objective practical methodological standardization to ensure accurate diagnosis, appropriate care, and chart patient progress.

Effects of Cognitive Stress on Voice Acoustics in Individuals With Hyperfunctional Voice Disorders

PURPOSE

Autonomic nervous system dysfunction has been implicated in the development and persistence of hyperfunctional voice disorders (HVDs). The purpose of this study was to determine the effects of cognitive stress, which is known to arouse the autonomic nervous system, on voice acoustics in female speakers with and without HVDs.

METHOD

Adult female speakers-66 with HVDs, 66 without-were recorded while speaking with and without a cognitive stressor. Root-mean-square (RMS) of amplitude, fundamental frequency (f _o), low-to-high spectral energy ratio (L/H ratio), cepstral peak prominence (CPP), and relative f _o (RFF) were measured for each speaker and cognitive stress condition. Mixed-model analyses of variance and post hoc t tests were conducted to determine if cognitive stress affected voice acoustics and whether voice changes were greater for those with HVDs.

RESULTS

All measures differed significantly under cognitive stress for speakers with and without HVDs. RMS and CPP increased whereas f _o, CPP, and RFF decreased under cognitive stress. Changes in these measures were not greater in those with HVDs.

CONCLUSION

Cognitive stress and presumed autonomic arousal affect voice similarly in female speakers with and without HVDs.

A randomized controlled trial of the effects of flow phonation voice treatment for primary muscle tension dysphonia

OBJECTIVE

The purpose of the study was to investigate the effects of flow phonation voice therapy on laryngeal physiology and vocal quality in persons with primary Muscle Tension Dysphonia (MTD1).

METHODS

Seventeen participants with a diagnosis of MTD1 completed the study. Participants were randomized to two groups. Group 1 (9 participants) received flow phonation treatment and individualized vocal hygiene education for 12 sessions over six weeks. Group 2 (8 participants) received vocal hygiene education only for three weeks (6 sessions), followed by another three weeks (6 sessions) of both vocal hygiene instruction and flow phonation therapy. Treatment consisted of cup-bubble blowing, gargling, and stretch and flow exercises. Visual-perceptual. auditory-perceptual, acoustic, aerodynamic and voice-related quality-of-life measures were obtained at three time points: before treatment, three weeks after initiation of treatment and after completion of treatment.

RESULTS

Voice quality was perceived to be significantly improved in both groups. Voice related quality-of-life trended toward improvement for both groups across time points. Changes in aerodynamic and acoustic measures did not reach statistical significance compared to baseline for both groups. Visual comparisons of laryngeal closure patterns demonstrated comparably better outcomes for Group 1.

CONCLUSIONS

Results of this study indicate flow phonation exercises can potentially be favorably employed for individuals with MTD1. In particular, it appears that the exercises aid in alleviating vocal hyperfunction, as evidenced by visual perceptual stroboscopic analysis, and clinically improved auditory-perceptual measures.

Ambulatory Monitoring of Subglottal Pressure Estimated from Neck-Surface Vibration in Individuals with and without Voice Disorders

The aerodynamic voice assessment of subglottal air pressure can discriminate between speakers with typical voices from patients with voice disorders, with further evidence validating subglottal pressure as a clinical outcome measure. Although estimating subglottal pressure during phonation is an important component of a standard voice assessment, current methods for estimating subglottal pressure rely on non-natural speech tasks in a clinical or laboratory setting. This study reports on the validation of a method for subglottal pressure estimation in individuals with and without voice disorders that can be translated to connected speech to enable the monitoring of vocal function and behavior in real-world settings. During a laboratory calibration session, a participant-specific multiple regression model was derived to estimate subglottal pressure from a neck-surface vibration signal that can be recorded during natural speech production. The model was derived for vocally typical individuals and patients diagnosed with phonotraumatic vocal fold lesions, primary muscle tension dysphonia, and unilateral vocal fold paralysis. Estimates of subglottal pressure using the developed method exhibited significantly lower error than alternative methods in the literature, with average errors ranging from 1.13 to 2.08 cm H₂O for the participant groups. The model was then applied during activities of daily living, thus yielding ambulatory estimates of subglottal pressure for the first time in these populations. Results point to the feasibility and potential of real-time monitoring of subglottal pressure during an individual's daily life for the prevention, assessment, and treatment of voice disorders.

Vocal Behavior of Teachers Reading with Raised Voice in a Noisy Environment

(1) Objective: Teaching is a particularly voice-demanding occupation. Voice training provided during teachers’ education is often insufficient and thus teachers are at risk of developing voice disorders. Vocal demands during teaching are not only characterized by speaking for long durations but also by speaking in noisy environments. This provokes the so-called Lombard effect, which intuitively leads to an increase in voice intensity, pitch and phonation time in laboratory studies. However, this effect has not been thoroughly investigated in realistic teaching scenarios. (2) Methods: This study thus examined how 13 experienced, but vocally untrained, teachers behaved when reading in a noisy compared to quiet background environment. The quiet and noisy conditions were provided by a live audience either listening quietly or making noise by talking to each other. By using a portable voice accumulator, the fundamental frequency, sound pressure level of the voice and the noise as well as the phonation time were recorded in both conditions. (3) Results: The results showed that the teachers mainly responded according to the Lombard effect. In addition, analysis of phonation time revealed that they failed to increase inhalation time and appeared to lose articulation through the shortening of voiceless consonants in the noisy condition. (4) Conclusions: The teachers demonstrated vocally demanding behavior when speaking in the noisy condition, which can lead to vocal fatigue and cause dysphonia. The findings underline the necessity for specific voice training in teachers’ education, and the content of such training is discussed in light of the results.

Integrative Review and Framework of Suggested Mechanisms in Primary Muscle Tension Dysphonia

PURPOSE

Despite the high prevalence of primary muscle tension dysphonia (MTD-1), its underlying mechanisms and their interrelationships have yet to be fully identified. The objectives of this integrative review were (a) to describe and classify the suggested underlying mechanisms for MTD-1, (b) to appraise the empirical evidence supporting each of the proposed mechanisms, and (c) to summarize the information in an integrative model.

METHOD

PubMed, Scopus, and CINAHL were searched for all publications pertaining to muscle tension dysphonia. Papers were retained if they included theoretical or empirical data pertaining to underlying mechanisms of MTD-1. A total of 921 papers initially qualified for screening, of which 100 remained for consideration in this review. Underlying mechanisms of MTD-1 were extracted using a consensus approach.

RESULTS

Seven broad categories of putative mechanisms involved in MTD-1 were identified: psychosocial, autonomic, sensorimotor, respiratory, postural, inflammatory, and neuromuscular. These categories were further divided into 19 subcategories detailed in the body of this review article. Based on the reviewed evidence, our proposed integrative model presents MTD-1 as an idiosyncratic motor adaptation to physiological perturbation or perceived threat. Under this model, physiologically or psychologically aversive stimuli can instigate a series of motor adaptations at multiple levels of the nervous system, ultimately disturbing muscle activation patterns and their biomechanical outcomes. Importantly, these adaptations appear to have the potential to become chronic even after threatening stimuli are withdrawn.

CONCLUSIONS

The proposed model highlights the importance of personalized rehabilitation in MTD-1 treatment. Limitations of the literature are discussed to provide guidance for future research aimed at improving our understanding of MTD-1.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.19586065.

Contribution of Undesired Medial Surface Shape to Suboptimal Voice Outcome After Medialization Laryngoplasty

OBJECTIVES

Voice production in pathological conditions or after surgical intervention often involves undesired medial surface shape such as reduced vertical thickness and/or left-right asymmetry in medial surface shape. The effect of such undesired medial surface on voice production remains unclear, and is often not taken into consideration during planning of surgical intervention, due to difficulty of imaging the medial surface in patients. This study aims to better understand how voice outcomes are impacted by undesired medial surface shape.

METHODS

Computational simulations were conducted to parametrically manipulate medial surface shape and stiffness and observe its consequence on voice production.

RESULTS

The results showed that undesired medial surface shape can result in incomplete glottal closure, weak voice production, increased phonation threshold, and significantly reduced vocal efficiency, particularly in the presence of left-right stiffness asymmetry.

CONCLUSIONS

In addition to approximating the vocal folds, medialization laryngoplasty should additionally aim to sufficiently increase medial surface thickness, which may improve voice outcomes in patients whose voices remain unsatisfactory or suboptimal after initial intervention. While a divergent implant may increase medial surface thickness, precise implant placement in anticipation of tissue and implant deformation during the insertion process is equally important in order to achieve desired medial surface shape and optimal voice outcomes.

The effects of Cricothyroid Visor Maneuver (CVM) therapy on the voice characteristics of patients with muscular tension dysphonia: A Case Series Study

OBJECTIVE

The purpose of this study was to assess the effects of a novel manual therapy, the Cricothyroid visor maneuver (CVM) therapy, on acoustic, auditory perceptual and self-assessment ratings in Muscle tension dysphonia (MTD) patients.

STUDY DESIGN

This was a retrospective study of 6 clinical cases.

MATERIALS AND METHOD

The study comprised 6 Persian speakers with MTD (2 men and 4 women) and mean age 38.50 ± 5.32 years. All patients underwent therapy between April and June 2021. Therapy was provided in five 30-minute sessions. This study used of acoustic measurement including smoothed cepstral peak prominence (CPPs), Dysphonia Severity Index (DSI), self-assessment scales include vocal tract discomfort scale (VTD), voice related quality of life (V-RQOL) and Consensus Auditory- Perceptual Evaluation of Voice (CAPE-V) for auditory perceptual assessment in pre- and post-CVM sessions.

RESULTS

In the present study the CPPs and DSI increased while only CPPs significantly changed in pre and post therapy (P < 0.05). Also, having done the therapy the total severity of dysphonia (CAPE-V) and VTD significantly decreased (P < 0.05) and V-RQOL significantly increased (P < 0.05).

CONCLUSIONS

These results suggest that CVM can be an effective method for promote significant improvements in acoustic measurements, auditory perceptual and self-assessment scales in patients with MTD.

Telepractice Considerations for Evaluation and Treatment of Voice Disorders: Tailoring to Specific Populations

PURPOSE

The aim of this clinical focus article is to provide recommendations for implementation of telepractice services for the evaluation and treatment of voice disorders and to use case examples to highlight the advantages of this modality of service delivery.

METHOD

In this clinical focus article, key factors for successful telepractice evaluation and treatment of voice and related disorders are discussed relative to clinical outcome measures. Case examples of telepractice voice therapy are described for a pediatric, transgender, and chronic cough client including associated acoustic, auditory-perceptual, and quality-of-life treatment outcomes.

RESULTS

Acoustic, perceptual, and quality-of-life outcome measures demonstrated functional voice improvements after treatment using the telepractice modality. The pediatric client showed decreased perceptual voice strain and increased speech intelligibility. The transgender client showed increased habitual speaking fundamental frequency (pitch) and quality of life. The chronic cough client showed improved vocal hygiene and reduced cough severity.

CONCLUSIONS

A review of the literature shows comparable outcomes for in-person and telepractice voice therapy, but special considerations must be made to ensure therapeutic success. We present three representative types of voice cases that illustrate implementation of voice evaluation and treatment using the telepractice modality. In all three cases, the clients' personal therapeutic goals were achieved without needing to travel to the clinic. Furthermore, asynchronous practice opportunities were found to be positive byproducts of using the telepractice modality.

Contribution of laryngeal size to differences between male and female voice production

In this study we investigated the effect of sex- and age-related differences in vocal fold length, thickness, and depth on voice production in a three-dimensional vocal fold model. The results showed that the cause-effect relationships between vocal fold physiology and voice production previously identified in an adult male-like vocal fold geometry remained qualitatively the same in vocal folds with geometry representative of adult females and children. We further showed that the often-observed differences in voice production between adult males, adult females, and children can be explained by differences in length and thickness. The lower F0, higher flow rate, larger vocal fold vibration amplitude, and higher sound pressure level (SPL) in adult males as compared to adult females and children can be explained by differences in vocal fold length. In contrast, the thickness effect dominated and contributed to the larger closed quotient of vocal fold vibration, larger normalized maximum flow declination rate, and lower H1-H2 in adult males as compared to adult females and children. The effect of differences in vocal fold depth was generally small. When targeting a specific SPL, adult males experienced a lower peak vocal fold contact pressure during phonation than adult females and children.

Voice Therapy According to the Rehabilitation Treatment Specification System: Expert Consensus Ingredients and Targets

Purpose Clinical trials have demonstrated that standardized voice treatment programs are effective for some patients, but identifying the unique individual treatment ingredients specifically responsible for observed improvements remains elusive. To address this problem, the authors used a taxonomy of voice therapy, the Rehabilitation Treatment Specification System (RTSS), and a Delphi process to develop the RTSS-Voice (expert consensus categories of measurable and unique voice treatment ingredients and targets). Method Initial targets and ingredients were derived from a taxonomy of voice therapy. Through six Delphi Rounds, 10 vocal rehabilitation experts rated the measurability and uniqueness of individual treatment targets and ingredients. After each round, revisions (guided by the experts' feedback) were finalized among a primary reader (a voice therapy expert) and two external readers (rehabilitation experts outside the field of voice). Consensus was established when the label and definition of an ingredient or target reached a supramajority threshold (≥ 8 of 10 expert agreement). Results Thirty-five target and 19 ingredient categories were agreed to be measurable, unique, and accurate reflections of the rules and terminology of the RTSS. Operational definitions for each category included differences in the way ingredients are delivered and the way individual targets are modified by those ingredients. Conclusions The consensus labels and operationalized ingredients and targets making up the RTSS-Voice have potential to improve voice therapy research, practice, and education/training. The methods used to develop these lists may be useful for other speech, language, and hearing treatment specifications. Supplemental Material https://doi.org/10.23641/asha.15243357.

Vocal parameters, muscle palpation, self-perception of voice symptoms, pain, and vocal fatigue in women with muscle tension dysphonia

PURPOSE

To identify muscle tension dysphonia (MTD) signs and symptoms, as well as to analyze the results of vocal parameters, the physical clinical examination of muscle palpation, the self-perception of vocal symptoms, vocal pain, and fatigue of women with MTD and compare them with women with healthy voices.

METHODS

a cross-sectional study with 45 women (23 with MTD and 22 controls), similar median age between groups. The speech-language and otorhinolaryngological evaluation determined the diagnosis of MTD. All participants responded to the Voice Symptoms Scale (VoiSS), Vocal Fatigue Index (VFI), and Nordic Musculoskeletal Questionnaire (NMQ) protocols. They were also assessed by a palpatory evaluation of the perilaryngeal musculature, auditory-perceptual evaluation, and acoustic analysis of the voice fundamental frequency. The speech sample included sustained vowels "a", "i" and "e" and connected speech, recorded in a silent environment, and submitted to auditory-perceptual evaluation by three judges. In the acoustic analysis, the fundamental frequency and maximum phonation times were extracted.

RESULTS

The MTD group had worse results in VoiSS, VFI, and NMQ, in addition to greater resistance to palpation and a high vertical position of the larynx. The vocal parameters also showed greater deviation in the MTD group, except for the fundamental frequency. There was no relationship between vocal symptoms, fatigue, or pain with the general degree of dysphonia in the MTD group, indicating important symptoms in mild or moderate vocal deviations.

CONCLUSION

women with MTD presented vocal symptoms, vocal fatigue, muscle pain, resistance to palpation and deviated vocal parameters when compared to vocally healthy women.

Computational simulations of respiratory-laryngeal interactions and their effects on lung volume termination during phonation: Considerations for hyperfunctional voice disorders

Glottal resistance plays an important role in airflow conservation, especially in the context of high vocal demands. However, it remains unclear if laryngeal strategies most effective in controlling airflow during phonation are consistent with clinical manifestations of vocal hyperfunction. This study used a previously validated three-dimensional computational model of the vocal folds coupled with a respiratory model to investigate which laryngeal strategies were the best predictors of lung volume termination (LVT) and how these strategies' effects were modulated by respiratory parameters. Results indicated that the initial glottal angle and vertical thickness of the vocal folds were the best predictors of LVT regardless of subglottal pressure, lung volume initiation, and breath group duration. The effect of vertical thickness on LVT increased with the subglottal pressure-highlighting the importance of monitoring loudness during voice therapy to avoid laryngeal compensation-and decreased with increasing vocal fold stiffness. A positive initial glottal angle required an increase in vertical thickness to complete a target utterance, especially when the respiratory system was taxed. Overall, findings support the hypothesis that laryngeal strategies consistent with hyperfunctional voice disorders are effective in increasing LVT, and that conservation of airflow and respiratory effort may represent underlying mechanisms in those disorders.

Differences in Daily Voice Use Measures Between Female Patients With Nonphonotraumatic Vocal Hyperfunction and Matched Controls

Purpose The purpose of this study was to obtain a more comprehensive understanding of the pathophysiology and impact on daily voice use of nonphonotraumatic vocal hyperfunction (NPVH). Method An ambulatory voice monitor collected 1 week of data from 36 patients with NPVH and 36 vocally healthy matched controls. A subset of 11 patients with NPVH were monitored after voice therapy. Daily voice use measures included neck-skin acceleration magnitude, fundamental frequency (f _o), cepstral peak prominence (CPP), and the difference between the first and second harmonic magnitudes (H1-H2). Additional comparisons included 118 patients with phonotraumatic vocal hyperfunction (PVH) and 89 additional vocally healthy controls. Results The NPVH group, compared to the matched control group, exhibited increased f _o (Cohen's d = 0.6), reduced CPP (d = -0.9), and less positive H1-H2 skewness (d = -1.1). Classifiers used CPP mean and H1-H2 mode to maximally differentiate the NPVH and matched control groups (area under the receiver operating characteristic curve of 0.78). Classifiers performed well on unseen data: the logit decreased in patients with NPVH after therapy; ≥ 85% of the control and PVH groups were identified as "normal" or "not NPVH," respectively. Conclusions The NPVH group's daily voice use is less periodic (CPP), is higher pitched (f _o), and has less abrupt vocal fold closure (H1-H2 skew) compared to the matched control group. The combination of CPP mean and H1-H2 mode appears to reflect a pathophysiological continuum in NPVH patients of inefficient phonation with minimal potential for phonotrauma. Further validation of the classification model is needed to better understand potential clinical uses. Supplemental Material https://doi.org/10.23641/asha.14390771.

Age and Sex Comparison of Aerodynamic Phonation Measurements Using Noninvasive Assessment

Purpose The goal of this study was to present vocal aerodynamic measurements from pediatric and adult participant pools. There are a number of anatomical changes involving the larynx and vocal folds that occur as children age and become adults. Data were collected using two methods of noninvasive aerodynamic assessment: mechanical interruption and labial interruption. Method A total of 154 participants aged 4-24 years old took part in this study. Ten trials were performed for both methods of airway interruption. To perform mechanical interruption, participants phonated /α/ for 10 s trials while a balloon valve interrupted phonation 5 times. For labial interruption, participants said /pα/ 5 times at comfortable and quiet volumes. Aerodynamic measures included subglottal pressure, phonation threshold pressure, mean airflow, laryngeal resistance, and others. Results One hundred one participants (51 females) successfully completed testing with both methods. Eight out of 20 measurements were found to have a statistically significant effect of participant age on measurements. Sex alone had a significant effect on vocal efficiency for the labial quiet method. Conclusions The data discussed here can be used to view age and sex trends in vocal aerodynamic measurements. When using either method of mechanical or labial interruption, participant age needs to be taken into account to properly interpret several aerodynamic parameters. A participant's sex is not as important when using these methods.

Aerodynamic and Acoustic Voice Measures Before and After an Acute Public Speaking Stressor

Purpose The goal of this study was to determine if differences in stress system activation lead to changes in speaking fundamental frequency, average oral airflow, and estimated subglottal pressure before and after an acute, psychosocial stressor. Method Eighteen vocally healthy adult females experienced the Trier Social Stress Test (TSST) to activate the hypothalamic-pituitary-adrenal axis. The TSST includes public speaking and performing mental arithmetic in front of an audience. At seven time points, three before the stressor and four after the stressor, the participants produced /pa/ repetitions, read the Rainbow Passage, and provided a saliva sample. Measures included (a) salivary cortisol level, (b) oral airflow, (c) estimated subglottal pressure, and (d) speaking fundamental frequency from the second sentence of the Rainbow Passage. Results Ten of the 18 participants experienced a hypothalamic-pituitary-adrenal axis response to stress as indicated by a 2.5-nmol/L increase in salivary cortisol from before the TSST to after the TSST. Those who experienced a response to stress had a significantly higher speaking fundamental frequency before and immediately after the stressor than later after the stressor. No other variable varied significantly due to the stressor. Conclusions This study suggests that the idiosyncratic and inconsistent voice changes reported in the literature may be explained by differences in stress system activation. In addition, laryngeal aerodynamic measures appear resilient to changes due to acute stress. Further work is needed to examine the influence of other stress systems and if these findings hold for dysphonic individuals.

Does More Compression Mean More Pressure? A New Classification for Muscle Tension Dysphonia

Objective The aims of this study were to test the hypothesis that greater supraglottic compression (anteroposterior or lateral) correlates with higher subglottic pressure (SGP) and to develop a classification of muscle tension dysphonia (MTD), based on the degree of supraglottic compression during speech. Method A prospective, cross-sectional study was conducted in a series of 37 consecutive patients diagnosed with MTD with an altered aerodynamic profile characterized by high SGP (more than 90 mmH₂O). Supraglottic anteroposterior and lateral compression were categorized in three grades and assessed during the laryngoscopic examination. All patients completed the Spanish Voice Handicap Index (VHI) questionnaire and completed an acoustic and aerodynamic voice assessment. The relationship between compression grade and VHI with SGP was analyzed. Results More than 90% of patients demonstrated some degree of anteroposterior compression, and 67% had some degree of lateral compression. The mean (SD) SGP was 111.03 (16.7) mmH₂O, and the mean VHI was 27.86 (12.5). The degree of SGP was statistically different in the different grades of anteroposterior compression, and also anteroposterior compression correlated with an SGP (p < .05). The degree of lateral compression was not correlated with SGP. Neither the degree of anteroposterior or lateral compression nor the value of SGP was found to correlate with VHI. Conclusions Because grade of anteroposterior compression correlates with SGP, these grades can be used for diagnosis and follow-up of MTD patients. To this end and on this basis, we propose a new classification for MTD. Unlike the established classification, our proposed one makes it possible to combine different laryngoscopic features, improving the description of the larynx during phonation.

Estimation of Subglottal Pressure From Neck Surface Vibration in Patients With Voice Disorders

Purpose Given the established linear relationship between neck surface vibration magnitude and mean subglottal pressure (Ps) in vocally healthy speakers, the purpose of this study was to better understand the impact of the presence of a voice disorder on this baseline relationship. Method Data were obtained from participants with voice disorders representing a variety of glottal conditions, including phonotraumatic vocal hyperfunction, nonphonotraumatic vocal hyperfunction, and unilateral vocal fold paralysis. Participants were asked to repeat /p/-vowel syllable strings from loud-to-soft loudness levels in multiple vowel contexts (/pa/, /pi/, /pu/) and pitch levels (comfortable, higher than comfortable, lower than comfortable). Three statistical metrics were computed to analyze the regression line between neck surface accelerometer (ACC) signal magnitude and Ps within and across pitch, vowel, and voice disorder category: coefficient of determination (r 2), slope, and intercept. Three linear mixed-effects models were used to evaluate the impact of voice disorder category, pitch level, and vowel context on the relationship between ACC signal magnitude and Ps. Results The relationship between ACC signal magnitude and Ps was statistically different in patients with voice disorders than in vocally healthy controls; patients exhibited higher levels of Ps given similar values of ACC signal magnitude. Negligible effects were found for pitch condition within each voice disorder category, and negligible-to-small effects were found for vowel context. The mean of patient-specific r 2 values was .63, ranging from .13 to .92. Conclusions The baseline, linear relationship between ACC signal magnitude and Ps is affected by the presence of a voice disorder, with the relationship being participant-specific. Further work is needed to improve ACC-based prediction of Ps, across treatment, and during naturalistic speech production.

Do Phonatory Aerodynamic and Acoustic Measures in Connected Speech Differ Between Vocally Healthy Adults and Patients Diagnosed with Muscle Tension Dysphonia?

OBJECTIVES

One of the presumed etiologies of primary muscle tension dysphonia (MTD) is a respiratory-phonatory disruption resulting in poor phonatory airflow in speech; however, few data exist on the differences between vocally healthy adults and patients diagnosed with MTD. The goal of this study was to compare aerodynamic and acoustic measures of self-perceived vocally healthy adults with patients diagnosed with MTD.

STUDY DESIGN

Retrospective, observational, matched cohort study.

METHODS

Vocally healthy adults age 19-60 years were matched on age, gender, and body mass index (BMI) to patients diagnosed with MTD. Recorded samples of the first four sentences of The Rainbow Passage were analyzed for between-group differences in the following acoustic and aerodynamic dependent measures in connected speech: mean airflow during voicing, breath number, reading passage duration, inspiratory and expiratory durations, phonation time, inspiratory and expiratory volumes, cepstral peak prominence (CPP), CPP standard deviation (CPP SD), low to high ratio (L/H ratio), L/H ratio SD, CPP Fo, CPP Fo SD, cepstral spectral index of dysphonia, and dB sound pressure level (SPL).

RESULTS

One hundred and seventy participants were studied; 85 patients diagnosed with primary MTD and 85 vocally healthy control participants. The two groups differed significantly in mean SPL, duration of the reading passage, and inspiratory and expiratory airflow duration (P ≤ 0.003). No significant differences were observed between the groups on any other phonatory aerodynamic or acoustic measure. Mean SPL, duration of the reading passage, and inspiratory and expiratory airflow durations were lower and longer, respectively, in patients with MTD. Ranges and standard deviations were greater for all aerodynamic and acoustic measurements in patients with MTD.

CONCLUSION

Large variability in aerodynamic and acoustic measurements were observed in patients with primary MTD with no salient differences at the group level compared to vocally healthy participants. Individual phonatory aerodynamic and acoustic profiles should be used when setting goals for patient treatment plans and to track response to treatment for patients with MTD. Taken in its entirety, connected speech from patients diagnosed with MTD essentially reflect normal acoustic and aerodynamic values.

Impact of Nonmodal Phonation on Estimates of Subglottal Pressure From Neck-Surface Acceleration in Healthy Speakers

Purpose The purpose of this study was to evaluate the effects of nonmodal phonation on estimates of subglottal pressure (Ps) derived from the magnitude of a neck-surface accelerometer (ACC) signal and to confirm previous findings regarding the impact of vowel contexts and pitch levels in a larger cohort of participants. Method Twenty-six vocally healthy participants (18 women, 8 men) were asked to produce a series of p-vowel syllables with descending loudness in 3 vowel contexts (/a/, /i/, and /u/), 3 pitch levels (comfortable, high, and low), and 4 elicited phonatory conditions (modal, breathy, strained, and rough). Estimates of Ps for each vowel segment were obtained by averaging the intraoral air pressure plateau before and after each segment. The root-mean-square magnitude of the neck-surface ACC signal was computed for each vowel segment. Three linear mixed-effects models were used to statistically assess the effects of vowel, pitch, and phonatory condition on the linear relationship (slope and intercept) between Ps and ACC signal magnitude. Results Results demonstrated statistically significant linear relationships between ACC signal magnitude and Ps within participants but with increased intercepts for the nonmodal phonatory conditions; slopes were affected to a lesser extent. Vowel and pitch contexts did not significantly affect the linear relationship between ACC signal magnitude and Ps. Conclusion The classic linear relationship between ACC signal magnitude and Ps is significantly affected when nonmodal phonation is produced by a speaker. Future work is warranted to further characterize nonmodal phonatory characteristics to improve the ACC-based prediction of Ps during naturalistic speech production.

A Comparison of the s/z Ratio to Instrumental Aerodynamic Measures of Phonation

OBJECTIVE

The purpose of this study was to examine how the s/z ratio and instrumental measures of laryngeal valving and voicing efficiency.

STUDY DESIGN

Prospective, cohort design.

METHODS

Fifteen adult males (mean age 28.3 years) and 15 adult females (mean age 29.2 years) with normal voice quality were recruited and compared on productions of the s/z ratio and instrumental aerodynamic measures. The aerodynamic measures included vital capacity, maximum phonation time, airflow rate during sustained and sentence production, subglottal pressure, and laryngeal airway resistance. These measures were obtained on the Phonatory Aerodynamic System Model 6600. Statistical analyses included a univariate analysis of variance to examine for differences between sexes for all the variables, and between the s/z ratios for each of the three trials. Pearson's Product Moment Correlations were performed to identify the strength and nature of any significant relationships between the s/z ratio and instrumental aerodynamics.

RESULTS

There were significant differences in the mean values between males and females only for the measures of vital capacity and maximum phonation time. There were no significant differences between the three trials for the s/z ratio. There was a significant moderate negative correlation between the s/z ratio and laryngeal airway resistance in females and between the s/z ratio and sentence airflow rate in males.

CONCLUSIONS

The s/z ratio demonstrated only a moderate correlation with limited instrumental measures of laryngeal valving. In the absence of clear evidence of its ability to accurately assess laryngeal valving, the s/z ratio should be used in combination with other instrumental measures of laryngeal aerodynamics for a better representation of aerodynamic functioning.

Descriptive Analysis of the Interactive Patterning of the Vocalization Subsystems in Healthy Participants: A Dynamic Systems Perspective

Purpose Normative data for many objective voice measures are routinely used in clinical voice assessment; however, normative data reflect vocal output, but not vocalization process. The underlying physiologic processes of healthy phonation have been shown to be nonlinear and thus are likely different across individuals. Dynamic systems theory postulates that performance behaviors emerge from the nonlinear interplay of multiple physiologic components and that certain patterns are preferred and loosely governed by the interactions of physiology, task, and environment. The purpose of this study was to descriptively characterize the interactive nature of the vocalization subsystem triad in subjects with healthy voices and to determine if differing subgroups could be delineated to better understand how healthy voicing is physiologically generated. Method Respiratory kinematic, aerodynamic, and acoustic formant data were obtained from 29 individuals with healthy voices (21 female and eight male). Multivariate analyses were used to descriptively characterize the interactions among the subsystems that contributed to healthy voicing. Results Group data revealed representative measures of the 3 subsystems to be generally within the boundaries of established normative data. Despite this, 3 distinct clusters were delineated that represented 3 subgroups of individuals with differing subsystem patterning. Seven of the 9 measured variables in this study were found to be significantly different across at least 1 of the 3 subgroups indicating differing physiologic processes across individuals. Conclusion Vocal output in healthy individuals appears to be generated by distinct and preferred physiologic processes that were represented by 3 subgroups indicating that the process of vocalization is different among individuals, but not entirely idiosyncratic. Possibilities for these differences are explored using the framework of dynamic systems theory and the dynamics of emergent behaviors. A revised physiologic model of phonation that accounts for differences within and among the vocalization subsystems is described. Supplemental Material https://doi.org/10.23641/asha.7616462.

Vocalization Subsystem Responses to a Temporarily Induced Unilateral Vocal Fold Paralysis

PURPOSE

The purpose of this study is to quantify the interactions of the 3 vocalization subsystems of respiration, phonation, and resonance before, during, and after a perturbation to the larynx (temporarily induced unilateral vocal fold paralysis) in 10 vocally healthy participants. Using dynamic systems theory as a guide, we hypothesized that data groupings would emerge revealing context-dependent patterns in the relationships of variables representing the 3 vocalization subsystems. We also hypothesized that group data would mask important individual variability important to understanding the relationships among the vocalization subsystems.

METHOD

A perturbation paradigm was used to obtain respiratory kinematic, aerodynamic, and acoustic formant measures from 10 healthy participants (8 women, 2 men) with normal voices. Group and individual data were analyzed to provide a multilevel analysis of the data. A 3-dimensional state space model was constructed to demonstrate the interactive relationships among the 3 subsystems before, during, and after perturbation.

RESULTS

During perturbation, group data revealed that lung volume initiations and terminations were lower, with longer respiratory excursions; airflow rates increased while subglottic pressures were maintained. Acoustic formant measures indicated that the spacing between the upper formants decreased (F3-F5), whereas the spacing between F1 and F2 increased. State space modeling revealed the changing directionality and interactions among the 3 subsystems.

CONCLUSIONS

Group data alone masked important variability necessary to understand the unique relationships among the 3 subsystems. Multilevel analysis permitted a richer understanding of the individual differences in phonatory regulation and permitted subgroup analysis. Dynamic systems theory may be a useful heuristic to model the interactive relationships among vocalization subsystems.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.5913532.

Evidence for Auditory-Motor Impairment in Individuals With Hyperfunctional Voice Disorders

PURPOSE

The vocal auditory-motor control of individuals with hyperfunctional voice disorders was examined using a sensorimotor adaptation paradigm.

METHOD

Nine individuals with hyperfunctional voice disorders and 9 individuals with typical voices produced sustained vowels over 160 trials in 2 separate conditions: (a) while experiencing gradual upward perturbations in the fundamental frequency (fo) of their auditory feedback (shift-up) and (b) under no auditory perturbation (control). The shift-up condition consisted of 4 ordered (fixed) phases: baseline (no perturbation), ramp (gradual increases in heard fo), hold (a consistently higher heard fo), and after-effect (no perturbation). Adaptive responses were defined as the difference in produced fo during control and shift-up conditions.

RESULTS

Adaptive responses were significantly different between groups. Individuals with typical voices generally showed compensatory adaptive responses, with decreased fo during the ramp and hold phases. Conversely, many individuals with hyperfunctional voice disorders instead displayed the opposite effect by following the direction of the perturbation. When fo was experimentally increased, speakers further increased their fo.

CONCLUSION

Results indicate that some individuals diagnosed with hyperfunctional voice disorders have disrupted auditory-motor control, suggesting atypical neurological function. These findings may eventually allow for the development of new interventions for hyperfunctional voice disorders.

Aerodynamic Patterns in Patients With Voice Disorders: A Retrospective Study

OBJECTIVE

A recently published retrospective chart review of aerodynamic profiles of women with primary muscle tension dysphonia by Gillespie et al (2013) identified various relationships between mean airflow rate (MFR) and estimated subglottal pressure (est-Psub). The current retrospective study expanded the diagnostic categories to include all voice disorders referred for voice therapy. Three research questions were proposed: (1) Are there differences in the MFR and the est-Psub compared with the normal control group? (2) Within the disordered population, are there different variations in the pairing of MFR and est-Psub? (3) If these variations exist, are they diagnosis specific?

METHODS

A retrospective chart review of patients seen for acoustic and aerodynamic voice assessment at the Emory Voice Center between January 1, 2013 and December 31, 2014, were examined for aerodynamic measures of est-Psub and MFR; of these, 192 met the inclusion criteria. Simple t test, two-step cluster analysis, and analysis of variance, as well as Tukey multiple comparisons, were performed using R and SPSS.

RESULTS

Mean est-Psub was significantly greater in the group with voice disorder than in the control group (P value < 0.001). However, no statistical significance was found when comparing the MFR with the control group (P value <0.59). Nine possible pairings of MFR and est-Psub were found. Sufficient evidence was not found to detect significant differences in these pairings across diagnostic groups.

CONCLUSION

With regard to the rate and interrelationships of MFR and est-Psub, the findings of this study are similar to those of Gillespie et al, that is, MFR and est-Psub are not determinate of diagnosis.

Assessment practices of Irish speech and language therapists in the evaluation of voice disorders

It is commonly accepted that the evaluation of voice disorders ought to include extensive perceptual, psychometric, and instrumental measurements. This serves to encapsulate the wide-reaching effects of such a disorder, from the physical impairment in voice production to the psycho-social impact of having a dysphonic voice. In spite of this, no international gold standard exists by which voice disorders should be evaluated, and so speech and language therapists (SLTs) are often tasked with developing an assessment battery for use in their own clinics. The purpose of this study is to determine whether the evaluation of voice disorders by Irish SLTs on a national scale is suitably comprehensive, with particular reference to the guidelines published by the European Laryngological Society. A total of 49 SLTs working in a variety of settings responded anonymously to an electronic survey regarding their assessment practices. Results indicate that therapists are comprehensive in non-instrumental evaluation of voice, but lack both access to and training in instrumental assessment techniques.

The Relationship Between Voice and Breathing in the Assessment and Treatment of Voice Disorders

Coordination between the larynx and lower airways is essential for normal voice production. Dyscoordination may contribute to myriad voice problems. The current study provides an overview of respiratory and laryngeal physiology as it relates to normal and disordered voice production, as well as a review of phonatory aerodynamic assessment practices. Finally, the integration of voice and breathing in common voice therapy programs is explored.

Detection of Simulated Vocal Dysfunctions Using Complex sEMG Patterns

Symptoms of voice disorder may range from slight hoarseness to complete loss of voice; from modest vocal effort to uncomfortable neck pain. But even minor symptoms may still impact personal and especially professional lives. While early detection and diagnosis can ameliorate that effect, to date, we are still largely missing reliable and valid data to help us better screen for voice disorders. In our previous study, we started to address this gap in research by introducing an ambulatory voice monitoring system using surface electromyography (sEMG) and a robust algorithm (HiGUSSS) for pattern recognition of vocal gestures. Here, we expand on that work by further analyzing a larger set of simulated vocal dysfunctions. Our goal is to demonstrate that such a system has the potential to recognize and detect real vocal dysfunctions from multiple individuals with high accuracy under both intra and intersubject conditions. The proposed system relies on four sEMG channels to simultaneously process various patterns of sEMG activation in the search for maladaptive laryngeal activity that may lead to voice disorders. In the results presented here, our pattern recognition algorithm detected from two to ten different classes of sEMG patterns of muscle activation with an accuracy as high as 99%, depending on the subject and the testing conditions.

Telepractice Versus In-Person Delivery of Voice Therapy for Primary Muscle Tension Dysphonia

PURPOSE

The purpose of this study was to investigate the utility of telepractice for delivering flow phonation exercises to persons with primary muscle tension dysphonia (MTD).

METHOD

Fourteen participants with a diagnosis of primary MTD participated, 7 on site and 7 at remote locations. Each participant received 12 treatment sessions across 6 weeks. Treatment consisted of flow phonation voice therapy exercises. Auditory-perceptual, acoustic, aerodynamic, and quality-of-life measures were taken before and after treatment.

RESULTS

Perceptual and quality-of-life measures were significantly better posttreatment and were statistically equivalent across groups. Acoustic and aerodynamic measures improved in both groups, but changes did not reach statistical significance. Results for the 2 service delivery groups were comparable, with no significant differences observed for perceptual and quality-of-life measures.

CONCLUSIONS

Although the American Speech-Language-Hearing Association supports the use of telepractice for speech-language pathology services, evidence for the use of telepractice for providing behavioral treatment to patients with MTD has been lacking. The results of this study indicate that flow phonation exercises can be successfully used for patients with MTD using telepractice.

The Effects of Hyper- and Hypocapnia on Phonatory Laryngeal Airway Resistance in Women

PURPOSE

The larynx has a dual role in the regulation of gas flow into and out of the lungs while also establishing resistance required for vocal fold vibration. This study assessed reciprocal relations between phonatory functions-specifically, phonatory laryngeal airway resistance (Rlaw)-and respiratory homeostasis during states of ventilatory gas perturbations.

METHOD

Twenty-four healthy women performed phonatory tasks while exposed to induced hypercapnia (high CO2), hypocapnia (low CO2), and normal breathing (eupnea). Effects of gas perturbations on Rlaw were investigated as were the reciprocal effects of Rlaw modulations on respiratory homeostasis.

RESULTS

Rlaw remained stable despite manipulations of inspired gas concentrations. In contrast, end-tidal CO2 levels increased significantly during all phonatory tasks. Thus, for the conditions tested, Rlaw did not adjust to accommodate ventilatory needs as predicted. Rather, stable Rlaw was spontaneously accomplished at the cost of those needs.

CONCLUSIONS

Findings provide support for a theory of regulation wherein Rlaw may be a control parameter in phonation. Results also provide insight into the influence of phonation on respiration. The work sets the foundation for future studies on laryngeal function during phonation in individuals with lower airway disease and other patient populations.