Intrinsic laryngeal muscle activity in response to autonomic nervous system activation

Relations Between Dysphonia and Personality: An Approximation From Gray' Theories

Our study sought to show the relation between dysphonia and personality traits as explained by Gray's theories. Personality traits were analyzed in a patient group of 141 patients who showed functional and congenital voice disorders. The results were compared to the control group made up of 99 vocally healthy individuals. Their objective voice quality was measured by using the Dysphonia Severity Index, Voice Handicap level was measured using the VHI-10, and a perceptive analysis was conducted with a listening jury. The results showed significant differences in Introversion and Neuroticism and a greater tendency for activating the behavioral inhibition system in the patient group. Such an influence was also evident in voice quality measures. The results were similar to specialized literature.

A multidimensional strategy to managing dysfunctional breathing and exercise-induced laryngeal obstruction in adolescent athletes

BACKGROUND

Exercise induced laryngeal obstruction (EILO) causes inspiratory distress in the upper airway in many adolescent athletes. The nature of EILO is not fully understood, and effective management strategies are lacking. This study aimed to assess the effectiveness of a multidimensional individually tailored intervention, including Norwegian Psychomotor Physiotherapy (NPMP), elements of cognitive behavioural therapy and a rehabilitation plan, in reducing inspiratory distress and dysfunctional breathing in adolescent athletes with EILO.

METHODS

A mixed methods design, which combined qualitative and quantitative research, was used. Data, including subjective experiences of respiratory distress, findings from body examinations and objective measurements of lung function and aerobic capacity were gathered before and after a five month intervention involving 18 participants.

RESULTS

Following the intervention, the participants showed a reduction in respiratory distress and anxiousness associated with their breathing difficulties. Furthermore, the participants reported to be more in control of their breathing. The body assessments revealed a more functional breathing motion and improved posture, which imply that the breathing was less thoracic and more diaphragmatic in rest and exercise in all participants after the intervention.

CONCLUSIONS

Our results suggest that a multidimensional individually tailored intervention, including NPMP based physiotherapy, cognitive behavioural therapy elements, and a rehabilitation plan may reduce inspiratory distress and dysfunctional breathing in athletes with EILO.

TRIAL REGISTRATION

ClinicalTrials.gov Protocol Registration and Results system NCT06033755, date of registration: September12, 2023. Retrospectively registered.

The Patient Experience: The Relationship Between Vocal Handicap, Congruency, Perceived Present Control, and Mood Across Four Voice Disorders

OBJECTIVE

The potential for negative sequalae in psychosocial well-being presents clinical importance to the assessment of voice disorders. Despite the impairment voice disorders cause in the psychosocial domain, the clinical assessment of these disorders relies heavily on visual perceptual judgments of the larynx, audio-perceptual, as well as acoustic and aerodynamic measures. While these measures aid in accurate diagnosis and are necessary for standard of care, they present little insight into the patient experience of having a voice disorder.

DESIGN

Retrospective between-subject, non-experimental design.

METHODS

Data from 335 patients from the University of Pittsburgh Voice Center were collected from scores of the Voice Handicap Index-10 (VHI-10) and two recent questionnaires, the Voice Present Perceived Control scale (VPPC), and the Vocal Congruency Scale (VCS). Examining how these voice-specific scales related to three mental health screeners for stress (Perceived Stress Scale-4), anxiety (Generalized Anxiety Disorder-7) and depression (Patient Health Questionnaire-9) were also examined. Patient diagnoses included primary muscle tension dysphonia (pMTD), unilateral vocal fold paralysis (UVFP), vocal fold atrophy, and mid membranous vocal fold lesions.

RESULTS

There were significant differences in scores from the voice-specific scales between diagnostic groups with UVFP being the highest (worst) in VHI-10 and UVFP being the lowest (worst) in VCS compared to healthy controls. There was no significant difference in VPPC scores between diagnostic groups. Results showed statistically significant inverse relationships between the VHI-10 and the VPPC and between the VHI-10 and VCS for all diagnostic groups. A significant direct relationship was found between the VPPC and the VCS for patients diagnosed with MTD, UVFP and Lesions. In sum, patients with UVFP presented with the most frequent and sometimes strongest relationships between voice and mental health measures.

DISCUSSION

This study marks an initial investigation into the nuanced patient experience of having a voice disorder. Three theoretically unrelated voice constructs: handicap, perceived control, and sense of self, were measured via self-report. Results from this study describe the patient experience correlating to these constructs with weak correlations to stress, anxiety, and depression. Findings also clearly suggest that patient experience varies among diagnostic groups, as well as varying constructs. Measures of multiple constructs of patient perception provide valuable insight into a patient's experience of their voice disorder, guidance on the direction of voice treatment, and justification for such treatments.

Self-Reported Stress, Trauma, and Prevalence of Laryngoresponders in the General Population

INTRODUCTION

It has been proposed that some individuals are "laryngoresponders" (LRs) in that their stress manifests in the laryngeal region and laryngeal functions (e.g., voice and breathing). Preliminary data support the notion that LRs might differ from nonlaryngoresponders (NLRs) in their self-reported past trauma and recent stress. The purpose of this study was to establish the point prevalence of self-identified LRs in the general population.

METHOD

Using a web-based questionnaire, participants reported up to 13 stress-vulnerable bodily regions and described symptom nature and severity for each region. At the end of the questionnaire, they were explicitly prompted to report whether their laryngeal region or its functions were affected by stress. Participants were categorized a posteriori as Unprompted LRs, Prompted LRs, Inconsistent LRs, or NLRs. We compared LR and NLR groups on the Perceived Stress Scale (PSS-10) and the Childhood Trauma Questionnaire (CTQ-SF). We also redistributed the survey to a subset of participants to establish grouping reliability.

RESULTS

A total of 1,217 adults responded to the survey, and 995 provided complete data sets. Of those, 15.7% were classified as Unprompted LRs, 26.7% as Prompted LRs, 3% as Inconsistent LRs, and 54.6% as NLRs. Unprompted LRs demonstrated significantly higher/worse PSS-10 and CTQ-SF scores than all other groups. Reliability of LR classification was moderate upon follow-up, κ = .62, 95% confidence interval [0.47, 0.77].

CONCLUSIONS

Unprompted LRs described their symptoms in ways that were indistinguishable from patients with functional voice disorders (e.g., throat clenches, voice gets tired easily, lose my voice, voice gets hoarse). The method of self-report solicitation impacted the resulting response. Specifically, the report of larynx-related symptoms differed substantially depending on whether or not the participants were directly prompted to consider the larynx and its related functions.

Social Determinants of Health: Implications for Voice Disorders and Their Treatment

PURPOSE

Adverse childhood experiences (ACEs) and related conditions, such as discrimination, are social determinants of health (SDOHs). Critical race theory (CRT) is a lens through which to understand SDOHs in a way that may impact our clinical care. When prolonged or chronic, SDOHs might cause toxic stress and trauma, which, in turn, adversely affect health and are shown to be relevant for some voice disorders. The goals of this tutorial are to (a) review the literature on SDOHs that potentially contribute to disparities; (b) discuss explanatory models and theories that describe how psychosocial factors influence health; (c) relate the foregoing information to voice disorders, highlighting functional voice disorders (FVDs) as a particular case in point; and (d) describe how trauma-informed care can improve patient outcomes and advance health equity for vulnerable populations.

CONCLUSIONS

This tutorial concludes with a call for heightened awareness of the role that SDOHs such as structural and individual discrimination may play in voice disorders, and a call for research into SDOHs, traumatic stress, and health disparities in this patient population. A call is also made for more universal practice of trauma-informed care in the clinical voice domain.

Acoustic Measures of Voice and Physiologic Measures of Autonomic Arousal During Speech as a Function of Cognitive Load in Older Adults

OBJECTIVES/HYPOTHESIS

The purpose of this study was to determine the relationships among cognitive loading, autonomic arousal, and acoustic measures of voice in healthy older adults.

STUDY DESIGN

Prospective and observational.

METHODS

Twelve healthy older adults (six females) produced a sentence containing an embedded Stroop task in each of two cognitive load conditions: congruent and incongruent. Three physiologic measures of autonomic arousal (pulse volume amplitude, pulse period, and skin conductance response amplitude) and four acoustic measures of voice (cepstral peak prominence, low-to-high spectral energy ratio, fundamental frequency, and sound pressure level) were analyzed in each cognitive load condition.

RESULTS

A logistic regression model was used to predict the cognitive load condition using participant as a categorical predictor and the four acoustic measures and three autonomic measures as continuous predictors. Skin conductance response amplitude and pulse volume amplitude were both predictive of cognitive load; however, no acoustic measures of voice were statistically significant predictors of cognitive load for older adults.

CONCLUSIONS

These findings support the idea that increased cognitive load is associated with increased autonomic nervous system activity in older adults. The lack of changes in acoustic measures of voice with increased cognitive load may result from age-related changes in vocal quality and speech subsystems.

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.

Immediate Effects of Mindfulness Meditation on the Voice

OBJECTIVES

The benefits of mindfulness meditation are well documented. This study evaluated the immediate effects of mindfulness meditation (MM) on the voice and voice user.

STUDY DESIGN

Prospective experimental study.

METHODS

Participants: 19 vocally healthy (VH) individuals, and 26 individuals with common voice disorders (CVD; benign lesions and hyperfunctional muscle tension) deemed stimulable for voice therapy. Exclusionary criteria: prior training or regular meditation practice. Participants recorded speech samples before and after a 11.5-minute prerecorded session of MM.

PRIMARY OUTCOMES

phonatory aerodynamics and participants' self-reported experience of voice.

SECONDARY OUTCOMES

self-reported anxiety, vocal acoustics, speech breathing patterns, and auditory-perceptual outcomes. Baseline self-reported measures of voice (Voice Handicap Index-10 - VHI-10), breathing (Dyspnea Index - DI), stress (Perceived Stress Scale - PSS), and trait mindfulness (Cognitive and Mindfulness Scale - Revised, CAMS-R, Five Facet Mindfulness Questionnaire - FFMQ) were compared between groups.

RESULTS

At baseline, CVD had significantly higher VHI-10 (P< 0.001) and DI (P= 0.0014), and lower trait mindfulness (CAMS-R, P= 0.02). No difference between groups for PSS or FFMQ. Changes postMM: decreased CPP for all-voiced sentences for VH (P= 0.003), decreased mean SPL (P= 0.012) on sustained vowel for VH, increased mean phonatory airflow during sustained vowel for CVD (P = 0.012). VH demonstrated a decrease in CPP on the all-voice sentence, and CVD demonstrated an increase, resulting in a significant between group difference (P= 0.013). Participants reported improvements in voice, emotional and physical states. State anxiety decreased for both groups (= < 0.001). No other objective outcomes reached significance.

CONCLUSIONS

After a brief MM, participants experienced improvement in physical, emotional, and cognitive states, and in their perceptions of their voice. Results indicate that a brief, single session of MM may be beneficial for some, but not sufficient to override habitual voice and speech patterns. Given the benefits of MM, future work should evaluate MM in a standard voice therapy protocol.

Stress Effects on Pharyngeal Air Pressure and Upper Esophageal Sphincter Pressure During Phonation: The Influence of Vocal Tract Semi-Occlusion

OBJECTIVES/HYPOTHESIS

The objective of this study was to determine whether vocal tract semi-occlusion (SOVT) influenced stress effects on pharyngeal air pressure and upper esophageal sphincter (UES) pressure during phonation. Relationships between dysphonia and stress are well recognized but poorly understood. Stress effects act globally on the body, and may be observed beyond intrinsic laryngeal muscles to include pharyngeal muscles and the UES, which contribute to voice modulation. Phonation with SOVT may provide resistance to stress effects on the vocal tract. We hypothesized that stress effects on pharyngeal air pressure and UES pressure would be measurable with a high-resolution, 360° pressure catheter, and that stress effects would be impacted differently by occlusal and non-occlusal phonatory tasks.

METHODS

Ten healthy adults performed sustained vowel tasks (comfortable /a/, and loud /a/), and SOVT tasks (bilabial fricative and straw phonation). Each task was performed during a baseline condition, and during stress induced through a cold pressor task. Pharyngeal air pressure and UES pressure were measured via high-resolution manometry. Changes in pressure between baseline and stress were compared among phonatory tasks.

RESULTS

Stress-induced changes to UES pressure differed by phonatory task (P < 0.01). Stress increased UES pressures during vowels, but had no effect during bilabial fricative, and decreased UES pressures during straw phonation. Change in UES pressure with stress was greater for comfortable /a/ and loud /a/ than straw phonation (P = 0.048 and P = 0.019, respectively), and was not significantly different between comfortable /a/ or loud /a/ and bilabial fricative. Stress-induced changes in pharyngeal air pressure were not significantly different among tasks.

CONCLUSIONS

These findings help identify possible mechanisms underlying the relationship between stress and voice, and point to the utility of SOVT tasks for training vocal tract resistance to stress. This methodology provides a foundation for measuring changes to extra-laryngeal components of the vocal tract during phonation.

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.

Stressed and Distressed: Potential Underpinnings of Exercise-Related Inspiratory Distress in Adolescent Sport Performers

Many adolescent sport performers present with exercise-related respiratory symptoms consistent with exercise-induced laryngeal obstruction (EILO). The pathogenic underpinnings of EILO are not fully resolved, and existing behavioral management includes therapies targeting laryngeal physiology whereas surgical interventions target laryngeal anatomical anomalies. Recent findings from research and clinical practice indicate that psychological stress and thoracic breathing co-occur with laryngeal tightness in adolescent sport performers with EILO. This Perspective article theorizes on this potential coexistence. It discusses possible underpinnings of respiratory symptoms (including EILO) and thoracic breathing in adolescent sport performers by considering the effects of various stressors to which adolescent sport performers are exposed, and the impact these may have on the breathing, including in terms of laryngeal narrowing. The effect of stress on the breathing is examined in light of the reciprocal communication between the brain and the body and the relationship between psychological stress and stress responses in the respiratory system mediated by the autonomic nervous system. To inform decision-making and clinical awareness in this area, it may be worth expanding the focus from targeting mainly laryngeal structures to also include constrictions of the airways and the effects of thoracic breathing on the larynx during exercise. The importance of considering respiratory distress from a multidimensional perspective, and of incorporating the complexity of sport performers' psychological and physical experiences in the management of their health and well-being, is emphasized.

IMPACT

This Perspective adds to the understanding of respiratory distress in populations other than adults, which is important and necessary.

LAY SUMMARY

Adolescent sport performers are exposed to a number of stressors that may affect breathing and laryngeal narrowing, which in turn may have implications for the management of their overall health and well-being.

Relationships Among Personality, Daily Speaking Voice Use, and Phonotrauma in Adult Female Singers

PURPOSE

This study sought to determine whether personality traits related to extraversion and impulsivity are more strongly associated with singers with nodules compared to vocally healthy singers and to understand the relationship between personality and the types of daily speaking voice use.

METHOD

Weeklong ambulatory voice recordings and personality inventories were obtained for 47 female singers with nodules and 47 vocally healthy female singers. Paired t tests investigated trait differences between groups. Relationships between traits and weeklong speaking voice measures (vocal dose, sound pressure level [SPL], neck surface acceleration magnitude [NSAM], fundamental frequency, cepstral peak prominence [CPP], and the ratio of the first two harmonic magnitudes [H 1 -H 2]) were examined using pairwise Pearson r coefficients. Multiple regressions were performed to estimate voice parameters that correlated with two or more traits.

RESULTS

Singers with nodules scored higher on the Social Potency scale (reflecting a tendency toward social dominance) and lower on the Control scale (reflecting impulsivity) compared to the vocally healthy singers. In vocally healthy singers, vocal dose measures were positively correlated with a combination of Wellbeing (i.e., happiness) and Social Potency, mean SPL was positively correlated with Wellbeing, SPL variability was positively correlated with Social Potency and negatively with Harm Avoidance, and CPP mean was positively correlated with Wellbeing. Singers with nodules had a negative correlation between NSAM skewness and Social Potency. Both groups had negative correlations between H 1 -H 2 mean and Social Potency and Social Closeness.

CONCLUSIONS

Singers with nodules are more socially dominant and impulsive than vocally healthy singers. Personality traits are related to daily speaking voice use, particularly in vocally healthy singers. Individuals with higher levels of traits related to happiness and social dominance and lower Harm Avoidance tended to speak more, with higher laryngeal forces, with more SPL variability, and with more pressed glottal closure, which could increase risk of phonotrauma.

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

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

Acoustic Variability in the Healthy Female Voice Within and Across Days: How Much and Why?

Purpose The aims of this study were (1) to quantify variability in voice production (as measured acoustically) within and across consecutive days in vocally healthy female speakers, (2) to identify which acoustic measures are sensitive to this variability, and (3) to identify participant characteristics related to such voice variability. Method Participants included 45 young women with normal voices who were stratified by age, specifically 18-23, 24-29, and 30-35 years. Following an initial acoustic and auditory-perceptual voice assessment, participants performed standardized field voice recordings 3 times daily across a 7-day period. Acoustic analyses involved 32 cepstral-, spectral-, and time-based measures of connected speech and sustained vowels. Relationships among acoustic data and select demographic, health, and lifestyle (i.e., participant-based) factors were also examined. Results Significant time-of-day effects were observed for acoustic analyses within speakers (p < .05), with voices generally being worse in the morning. No significant differences were observed across consecutive days. Variations in voice production were associated with several participant factors, including improved voice with increased voice use; self-perceived poor voice function, minimal or no alcohol consumption, and extroverted personality; and worse voice with regular or current menstruation, depression, and anxiety. Conclusions This acoustic study provides essential information regarding the nature and extent to which healthy voices vary throughout the day and week. Participant-based factors that were associated with improved voice over time included increased voice use, self-perceived poor voice function, minimal or no alcohol consumption, and extroverted personality. Factors associated with worse voice production over time included regular or current menstruation, and depression and anxiety.

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.

Changes in Relative Fundamental Frequency Under Increased Cognitive Load in Individuals With Healthy Voices

Purpose The purpose of this study was to determine the effect of cognitive load on relative fundamental frequency (RFF) in individuals with healthy voices. Method Twenty adults with healthy voices read sentences under different cognitive load conditions. Each sentence contained color terms printed in colored ink, creating an embedded Stroop task. Participants read the ink color in which a word was printed, rather than the color term itself. Sentences with mismatched ink colors and printed words constituted an increased cognitive load. RFF, an acoustic correlate of laryngeal tension, was calculated for the 10 voicing cycles preceding (i.e., offset) and following (i.e., onset) voiceless consonants. Repeated measures analyses of variance were constructed to assess the effects of RFF cycle, cognitive load, and their interaction on mean RFF offset and onset. Results There was a significant effect of cognitive load condition on RFF offset. There was no significant effect of condition on RFF onset nor significant interaction between cycle and condition on RFF onset or offset values. Conclusion Reduced mean RFF offset may indicate an increase in laryngeal muscle tension during a cognitively demanding task.

Vocal fold kinematics and relative fundamental frequency as a function of obstruent type and speaker age

The acoustic measure, relative fundamental frequency (RFF), has been proposed as an objective metric for assessing vocal hyperfunction; however, its underlying physiological mechanisms have not yet been fully characterized. This study aimed to characterize the relationship between RFF and vocal fold kinematics. Simultaneous acoustic and high-speed videoendoscopic (HSV) recordings were collected as younger and older speakers repeated the utterances /ifi/ and /iti/. RFF values at voicing offsets and onsets surrounding the obstruents were estimated from acoustic recordings, whereas glottal angles, durations of voicing offset and onset, and a kinematic estimate of laryngeal stiffness (KS) were obtained from HSV images. No differences were found between younger and older speakers for any measure. RFF did not differ between the two obstruents at voicing offset; however, fricatives necessitated larger glottal angles and longer durations to devoice. RFF values were lower and glottal angles were greater for stops relative to fricatives at voicing onset. KS values were greater in stops relative to fricatives. The less adducted vocal folds with greater KS and lower RFF at voicing onset for stops relative to fricatives in this study were in accordance with prior speculations that decreased vocal fold contact area and increased laryngeal stiffness may decrease RFF.

Intrinsic Laryngeal Muscle Activity During Subvocalization

PURPOSE

Subvocalization, the low-grade activity of speech articulator muscles while thinking or reading, may mediate phonological representations of verbal material. However, no literature exists that directly measures whether intrinsic laryngeal muscles (ILMs) are active during subvocalization. The possibility of ILM activation during subvocalization has implications for establishing appropriate baselines when experimental conditions involve linguistic features.

METHOD

In two separate studies, forty-five cisgender women completed one or two silentsil tasks (two in the first study, Experiments 1a and 1b, and one in the second, Experiment 2). Fine wire electromyography was used to directly measure ILM activity during an at-rest baseline and silent tasks used to determine whether subvocalization occurred (referred to hereafter as "subvocalization tasks"). Other muscles were measured via surface electromyography: submental muscle in Experiments 1a and 1b, anterior tibialis in Experiment 2, and upper trapezius in all experiments.

RESULTS

Interrupted time-series analysis was used to directly measure changes in ILM activity from baseline to the subvocalization tasks. A paired two tailed t-test was used to measure mean differences in ILM activity across conditions for each participant. Some individuals displayed statistically significant increases from baseline during subvocalization tasks, whereas others displayed decreases. Cohen's d was used to calculate the effect size for each muscle across the three subvocalization conditions. Of the 21 muscles measured across three experiments, five yielded a small mean effect size, and the effect sizes for the remaining 16 muscles were negligible. At a group level, only the right cricothyroid showed statistically significant changes (Experiment 1b).

CONCLUSION

The ILM responses during subvocalization vary in both magnitude and direction. Most but not all changes can be described as negligible. For future studies of ILM activity during conditions that involve linguistic processing, investigators should consider the idiosyncratic variation during subvocalization when determining the most appropriate baseline task.

An Updated Theoretical Framework for Vocal Hyperfunction

Purpose The purpose of this viewpoint article is to facilitate research on vocal hyperfunction (VH). VH is implicated in the most commonly occurring types of voice disorders, but there remains a pressing need to increase our understanding of the etiological and pathophysiological mechanisms associated with VH to improve the prevention, diagnosis, and treatment of VH-related disorders. Method A comprehensive theoretical framework for VH is proposed based on an integration of prevailing clinical views and research evidence. Results The fundamental structure of the current framework is based on a previous (simplified) version that was published over 30 years ago (Hillman et al., 1989). A central premise of the framework is that there are two primary manifestations of VH-phonotraumatic VH and nonphonotraumatic VH-and that multiple factors contribute and interact in different ways to cause and maintain these two types of VH. Key hypotheses are presented about the way different factors may contribute to phonotraumatic VH and nonphonotraumatic VH and how the associated disorders may respond to treatment. Conclusions This updated and expanded framework is meant to help guide future research, particularly the design of longitudinal studies, which can lead to a refinement in knowledge about the etiology and pathophysiology of VH-related disorders. Such new knowledge should lead to further refinements in the framework and serve as a basis for improving the prevention and evidence-based clinical management of VH.

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.

Intrinsic Laryngeal Muscle Response to a Public Speech Preparation Stressor: Personality and Autonomic Predictors

Purpose Laboratory stressors have been shown to impact the activity of the intrinsic laryngeal muscles (ILMs), which may be part of the final causal pathway in some stress-induced voice disorders. Previous research suggests that personality traits such as stress reaction might increase one's susceptibility to these problems. Also, the autonomic nervous system response is implicated in the pathogenesis of voice disorders putatively involving ILM hyperfunction. The purpose of this study was to investigate personality and autonomic nervous system predictors of ILM responses to stressor exposure. Method Thirty-seven physically and vocally healthy female adults completed a personality questionnaire and were subjected to a speech preparation task intended to induce stress. Fine wire electromyography of the ILMs was performed so that the activity of these muscles could be measured prior to and during the stressor. Participants' trait stress reaction was measured as a personality-based predictive variable, as was respiratory-corrected respiratory sinus arrhythmia, a putative measure of vagal outflow to the heart. Results The personality measure trait stress reaction uniquely predicted thyroarytenoid, trapezius, and tibialis activity, whereas respiratory sinus arrhythmia uniquely predicted the activity of all muscles studied. Differences were observed in the autonomic predictor variable as a function of whether or not effects of respiration were accounted for in the variable's calculation. Conclusions This study explores the potential mediating roles of personality and autonomic function in ILM activity during a stressor. Both variables have value in predicting ILM activity during stressor exposure.

Dysphonia, Perceived Control, and Psychosocial Distress: A Qualitative Study

OBJECTIVES

The purpose of this qualitative study was to examine relationships between psychological factors, particularly perceived control, and voice symptoms in adults seeking treatment for a voice problem.

METHODS

Semistructured interviews of adult patients with a clinical diagnosis of muscle tension dysphonia were conducted and transcribed. Follow-up interviews were conducted as needed for further information or clarification. A multidisciplinary team analyzed interview content using inductive techniques. Common themes and subthemes were identified. A conceptual model was developed describing the association between voice symptoms, psychological factors, precipitants of ongoing voice symptoms, and perceived control.

RESULTS

Thematic saturation was reached after 23 interviews. No participants reported a direct psychological cause for their voice problem, although half described significant life events preceding voice problem onset (eg, miscarriage and other health events, interpersonal conflicts, and family members' illnesses, injuries, and deaths). Participants described psychological influences on voice symptoms that led to rapid exacerbation of their voice symptoms. Participants described the helpfulness of speech therapy and sometimes also challenges of applying techniques in daily life. They also discussed personal coping strategies that included behavioral (eg, avoiding triggers and seeking social support) and psychological (eg, mind-body awareness and emotion regulation) components. Voice-related perceived control was associated with adaptive emotional and behavioral responses, which appeared to facilitate symptom improvement.

CONCLUSIONS

In this qualitative pilot study, participant narratives suggested that psychological factors and emotions influence voice symptoms, facilitating development of a preliminary conceptual model of how adaptive and maladaptive responses develop and how they influence vocal function.

The Study of Laryngoscopic and Autonomic Patterns in Exercise-Induced Laryngeal Obstruction

OBJECTIVES

(1) Identify laryngeal patterns axiomatic to exercise-induced laryngeal obstruction (EILO) and (2) investigate the role of autonomic function in EILO.

METHODS

Twenty-seven athletic adolescents (13 EILO, 14 control) underwent laryngoscopy at rest and exercise. Glottal configurations, supraglottic dynamics, systolic blood pressure responses, and heart rate recovery were compared between conditions and groups.

RESULTS

Inspiratory glottal angles were smaller in the EILO group than the control group with exercise. However, group differences were not statistically significant ( P > .05), likely due to high variability of laryngeal responses in the EILO group. Expiratory glottal patterns showed statistically greater abductory responses to exercise in the control group ( P = .001) but not the EILO group ( P > .05). Arytenoid prolapse occurred variably in both groups. Systolic blood pressure responses to exercise were higher in the control group, and heart rate recovery was faster in the EILO group. However, no significant differences were seen between the 2 groups on either autonomic parameter ( P > .05).

CONCLUSIONS

"Paradoxical" inspiratory and blunted expiratory vocal fold pattern responses to exercise best characterize EILO. Group differences were only seen with exercise challenge, thus highlighting the utility of provocation and control groups to identify EILO.

Intrinsic Laryngeal Muscle Response to a Public Speech Preparation Stressor

PURPOSE

Research suggests that abnormal levels of intrinsic laryngeal muscle (ILM) contraction is a potential causal factor in stress-induced voice disorders. This study seeks to characterize the ILM stress response in a cohort of vocally healthy women.

METHOD

The authors used an unblinded, nonrandomized, repeated-measures design. Forty vocally healthy female adults were subjected to a stressful speech preparation task. Measurements of heart rate, blood pressure, trapezius muscle (positive control) activation, and tibialis muscle (negative control) activation were obtained from 37 participants before and during stressor exposure, in a nonvoice and nonspeaking task paradigm, to confirm physiological stress response compared to baseline. Fine wire electromyography of the ILMs (posterior cricoarytenoid, thyroarytenoid/lateral cricoarytenoid muscle complex, and cricothyroid) was performed simultaneously so that the activity of these muscles could be measured prior to and during stressor exposure.

RESULTS

The protocol successfully elicited the typical and expected physiological stress responses. Findings supported the hypothesis that, in some individuals, the ILMs significantly increase in activity during stress reactions compared to baseline, as do the control muscles.

CONCLUSIONS

This study characterizes ILM responses to psychological stress in vocally healthy participants. Some of the female adults in this study appeared to be "laryngeal stress responders," as evidenced by increased activity of the ILMs during a silent (i.e., nonvocal, nonspeech) speech preparation task that they considered to be stressful.

Exercise-induced laryngeal obstruction in athletes: Contributory factors and treatment implications

Otherwise healthy adolescent athletes presenting with respiratory symptoms consistent with exercise-induced laryngeal obstruction (EILO) are frequently encountered in clinical practice. The symptoms are often incorrectly considered to result from exercise-induced asthma, and may be wrongly treated as such. Given the potential implications for health and performance if EILO is left untreated, a more comprehensive understanding of contributory mechanisms is essential in order to create appropriate treatment procedures. Informed by knowledge from physical therapy, as well as the fields of voice rehabilitation and vocal pedagogy, this theoretical article presents a novel way of understanding and managing EILO by exploring bodily mechanisms and structures that may disturb laryngeal function during strenuous exercise. Firstly, the status quo of the EILO diagnosis, its aetiology and treatment options are reviewed. Secondly, considerations associated with laryngeal structures and mechanisms, and their potential influence on laryngeal movement and sensitivity are examined. Thirdly, the manner in which postural de-alignment and breathing pattern may interfere with laryngeal functioning will be discussed. Finally, interventions for voice disorders and singing and the relevance of these for EILO are evaluated. It is argued that clients with EILO should undergo a thorough physical examination to identify constrictions in the body as a whole - such as postural de-alignments and a dysfunctional breathing pattern - as these are hypothesized as playing a critical role in laryngeal tightness during exercise. Physical therapists possess particular skills and competence with regard to examining breathing patterns and postural de-alignments, and should be included in the treatment process of EILO.

Laryngocardiac Reflex: A Case Report and Review of the Literature

INTRODUCTION

The vagus nerve has sensory and motor function in the larynx, as well as parasympathetic function in the thorax and abdomen. Stimulation of the superior laryngeal nerve can cause reflexive bradycardia.

CASE

We describe a case of a 45-year-old man with pre-syncopal symptoms while exercising, and bradycardia found during cardiology workup. Radiography and flexible laryngoscopy showed evidence of a right-sided, vascular laryngeal mass. Exercise testing before and after superior laryngeal nerve block showed reversal of the symptoms with the block. Subsequent resection of the lymphovascular malformation with CO₂ laser eliminated the patient's symptoms.

DISCUSSION

This is the first case reported of the laryngocardiac reflex producing symptomatic bradycardia as a result of exercise-induced engorgement of a supraglottic lymphovascular malformation, which was then cured by surgical excision. We discuss this case and the literature regarding lymphovascular malformations in the airway and the neural pathways of the laryngocardiac reflex.

Investigating the Role of Salivary Cortisol on Vocal Symptoms

PURPOSE

We investigated whether participants who reported more often occurring vocal symptoms showed higher salivary cortisol levels and if such possible associations were different for men and women.

METHOD

The participants (N = 170; men n = 49, women n = 121) consisted of a population-based sample of Finnish twins born between 1961 and 1989. The participants submitted saliva samples for hormone analysis and completed a web questionnaire including questions regarding the occurrence of 6 vocal symptoms during the past 12 months. The data were analyzed using the generalized estimated equations method.

RESULTS

A composite variable of the vocal symptoms showed a significant positive association with salivary cortisol levels (p < .001). Three of the 6 vocal symptoms were significantly associated with the level of cortisol when analyzed separately (p values less than .05). The results showed no gender difference regarding the effect of salivary cortisol on vocal symptoms.

CONCLUSIONS

There was a positive association between the occurrence of vocal symptoms and salivary cortisol levels. Participants with higher cortisol levels reported more often occurring vocal symptoms. This could have a connection to the influence of stress on vocal symptoms because stress is a known risk factor of vocal symptoms and salivary cortisol can be seen as a biomarker for stress.

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.

Acoustic Measures of Voice and Physiologic Measures of Autonomic Arousal during Speech as a Function of Cognitive Load

OBJECTIVES/HYPOTHESIS

This study aimed to determine the relationship among cognitive load condition and measures of autonomic arousal and voice production in healthy adults.

STUDY DESIGN

A prospective study design was conducted.

METHODS

Sixteen healthy young adults (eight men, eight women) produced a sentence containing an embedded Stroop task in each of two cognitive load conditions: congruent and incongruent. In both conditions, participants said the font color of the color words instead of the word text. In the incongruent condition, font color differed from the word text, creating an increase in cognitive load relative to the congruent condition in which font color and word text matched. Three physiologic measures of autonomic arousal (pulse volume amplitude, pulse period, and skin conductance response amplitude) and four acoustic measures of voice (sound pressure level, fundamental frequency, cepstral peak prominence, and low-to-high spectral energy ratio) were analyzed for eight sentence productions in each cognitive load condition per participant.

RESULTS

A logistic regression model was constructed to predict the cognitive load condition (congruent or incongruent) using subject as a categorical predictor and the three autonomic measures and four acoustic measures as continuous predictors. It revealed that skin conductance response amplitude, cepstral peak prominence, and low-to-high spectral energy ratio were significantly associated with cognitive load condition.

CONCLUSIONS

During speech produced under increased cognitive load, healthy young adults show changes in physiologic markers of heightened autonomic arousal and acoustic measures of voice quality. Future work is necessary to examine these measures in older adults and individuals with voice disorders.

Underlying Mechanisms in Episodic Laryngeal Breathing Disorders

The study and management of episodic laryngeal breathing disorders (ELBD)—characterized by paradoxical laryngeal movement patterns and dyspnea—has traditionally focused on clinical presentation of these conditions. However, the underlying mechanisms driving these entities are largely unknown. This article provides a review of potential underlying mechanisms driving clinical expression in ELBD and suggests approaches to the future study of ELBD etiology.

Manual therapy and exercise to improve outcomes in patients with muscle tension dysphonia: a case series

BACKGROUND AND PURPOSE

Muscle tension dysphonia (MTD), a common voice disorder that is not commonly referred for physical therapy intervention, is characterized by excessive muscle recruitment, resulting in incorrect vibratory patterns of vocal folds and an alteration in voice production. This case series was conducted to determine whether physical therapy including manual therapy, exercise, and stress management education would be beneficial to this population by reducing excess muscle tension.

CASE DESCRIPTION

Nine patients with MTD completed a minimum of 9 sessions of the intervention. Patient-reported outcomes of pain, function, and quality of life were assessed at baseline and the conclusion of treatment. The outcome measures were the numeric rating scale (NRS), Patient-Specific Functional Scale (PSFS), and Voice Handicap Index (VHI). Cervical and jaw range of motion also were assessed at baseline and postintervention using standard goniometric measurements.

OUTCOMES

Eight of the patients had no pain after treatment. All 9 of the patients demonstrated an improvement in PSFS score, with 7 patients exceeding a clinically meaningful improvement at the conclusion of the intervention. Three of the patients also had a clinically meaningful change in VHI scores. All 9 of the patients demonstrated improvement in cervical flexion and lateral flexion and jaw opening, whereas 8 patients improved in cervical extension and rotation postintervention.

DISCUSSION

The findings suggest that physical therapists can feasibly implement an intervention to improve outcomes in patients with MTD. However, a randomized clinical trial is needed to confirm the results of this case series and the efficacy of the intervention. A clinical implication is the expansion of physical therapy to include referrals from voice centers for the treatment of MTD.

The effects of emotional expression on vibrato

OBJECTIVES/HYPOTHESIS

The purpose of this study was to investigate the effect of emotional expression on several acoustic measures of vibrato, including its rate, extent, and steadiness. We hypothesized that singing a passage with emotional content would influence these variables.

STUDY DESIGN

This study used a within-subjects, repeated-measures design. Singer performance under different conditions was analyzed.

METHODS

Ten graduate student singers (eight women, two men) completed a series of tasks including sustained sung vowels at several pitch and loudness levels, an assigned song that was judged to have relatively neutral emotion, and a personal selection that included passages of intense emotion. Vowel tokens were extracted from the recordings and averaged for each task. Dependent measures included the mean fundamental frequency (F0), mean intensity, frequency modulation (FM) rate, FM extent, and measures of FM rate and extent variability.

RESULTS

The FM rate and extent were higher and the modulation variability was lower for the more emotional song than for the sustained vowels. Mean F0 and intensity were higher for the emotional song than for the neutral song.

CONCLUSIONS

Singing an emotional passage influences acoustic features of vibrato when compared with isolated, sustained vowels. The wider dynamic and pitch ranges for emotional passages only partly explain vibrato differences between emotional and neutral singing.

Psychobiological stress reactivity and personality in persons with high and low stressor-induced extralaryngeal reactivity

PURPOSE

The purpose of the study was to determine whether persons who responded with high stressor-induced extralaryngeal muscle activity in a stress reactivity protocol differed from those with low muscle activity on measures of emotional and autonomic cardiovascular reactivity and personality.

METHOD

Thirty-six vocally healthy women (18-35 years) were assigned to high and low extralaryngeal groups based on submental (SM) and infrahyoid (IH) surface electromyography (sEMG) recordings obtained during a stress reactivity protocol (high vs. low sEMGSM and sEMGIH, n = 18 per subgroup; Dietrich & Verdolini Abbott, 2012). Measures included assessments of basic fear and fear of public speaking, rumination, systolic blood pressure (SBP), and personality.

RESULTS

The high sEMGIH group reported significantly greater basic fear across experimental phases than did the low sEMGIH group (p = .036). However, the high sEMGSM and sEMGIH versus low sEMGSM and sEMGIH groups did not differ on fear of public speaking, rumination, or SBP across phases. Both high sEMGSM and sEMGIH groups were characterized by significantly lower scores on Extraversion (p < .001).

CONCLUSION

In combination with the authors' previous findings (Dietrich & Verdolini Abbott, 2012), the present findings provided robust evidence that low Extraversion was linked to stressor-induced changes in extralaryngeal functioning and that perceived fear played a contributing role.