Presentation of the ATLETAS DA VOZ™ Conditioning Program

Objectives: To present a simple form of vocal and breathing conditioning for voice professionals based on concepts from vocal science. The vocal conditioning program called Voice Athletes Conditioning uses the principles of exercise physiology to gradually improve vocal and respiratory overload to achieve endurance, power, and flexibility. Methods: Due to our personal experience with high voice users, we synthesized a vocal conditioning program (AVCP) that combines voice science, exercise physiology, sports science and physical therapy principles. This is an 8-week program of daily vocal and breathing exercises with overload enhancement each week using different types of breathing devices and semi-occluded vocal tract exercises, designed and developed according to the specific requirements and performance of the voice professional. Reflections: Professional voice users often experience episodes of vocal fatigue that can directly affect their performance and vocal health. As with physical training for athletes, voice exercises can also contribute to improving vocal conditioning, preventing voice disorders, as well as helping to obtain better performance, greater tolerance to fatigue and shorter recovery time. Conclusions: AVCP is an approach that considers the principles of muscle training aimed objectively at the respiratory and vocal muscles, carried out with a variety of breathing devices and specific vocal exercises in search of greater performance time, less physiological stress, and shorter recovery time in the professional use of the voice.

Objetivos: Presentar una forma sencilla de acondicionamiento vocal y respiratorio para profesionales de la voz, basada en conceptos de la ciencia vocal. El programa de acondicionamiento vocal denominado Voice Athletes Conditioning utiliza los principios de la fisiología del ejercicio para mejorar gradualmente la sobrecarga vocal y respiratoria, con el fin de lograr resistencia, potencia y flexibilidad. Métodos: Debido a nuestra experiencia personal con usuarios de voz aguda, sintetizamos un programa de acondicionamiento vocal (AVCP) que combina principios de la ciencia de la voz, la fisiología del ejercicio, las ciencias del deporte y la fisioterapia. Se trata de un programa de 8 semanas de ejercicios vocales y respiratorios diarios con realce de sobrecarga cada semana utilizando diferentes tipos de dispositivos respiratorios y ejercicios semioclusivos del tracto vocal, diseñado y desarrollado de acuerdo con los requerimientos específicos y el rendimiento del profesional de la voz. Reflexiones: Los usuarios profesionales de la voz experimentan a menudo episodios de fatiga vocal que pueden afectar directamente su rendimiento y salud vocal. Al igual que ocurre con el entrenamiento físico de los deportistas, los ejercicios vocales también pueden contribuir a mejorar el acondicionamiento vocal, prevenir trastornos de la voz, además de ayudar a obtener un mejor rendimiento, una mayor tolerancia a la fatiga y un menor tiempo de recuperación. Conclusiones: El AVCP es un enfoque que considera los principios del entrenamiento muscular dirigido objetivamente a la musculatura respiratoria y vocal, realizado con diversos aparatos respiratorios y ejercicios vocales específicos en busca de un mayor tiempo de actuación, menor estrés fisiológico y menor tiempo de recuperación en el uso profesional de la voz.

Next-Generation Sequencing Application: A Systematic Approach for High-Quality RNA Isolation from Skeletal Muscles.

RNA extraction and analyses from tissues using bulk RNA-Sequencing (RNA-Seq) provide a more accurate picture of the gene expression compared to other molecular biology techniques for RNA quantification. Challenges associated with high-quality RNA extraction from skeletal muscles require a modification of standard protocols. Here, we describe a procedure for high-quality RNA isolation from intrinsic laryngeal muscles transferable to skeletal muscles with comparable technical and biological difficulties. Standard protocols for RNA isolation were optimized by maximizing the pooling strategy, determining the sample weight, applying cryogenic muscle disruption, and incorporating RNase-inhibiting reagents during the tissue preparation steps.

Transcriptome Analysis of Left Versus Right Intrinsic Laryngeal Muscles Associated with Innervation.

OBJECTIVES/HYPOTHESIS: Recurrent laryngeal nerve injury diagnosed as idiopathic or due to short-term surgery-related intubation exhibits a higher incidence of left-sided paralysis. While this is often attributed to nerve length, it is hypothesized there are asymmetric differences in the expression of genes related to neuromuscular function that may impact reinnervation and contribute to this laterality phenomenon. To test this hypothesis, this study analyzes the transcriptome profiles of the intrinsic laryngeal muscles (ILMs), comparing gene expression in the left versus right, with particular attention to genetic pathways associated with neuromuscular function. STUDY DESIGN: Laboratory experiment. METHODS: RNA was extracted from the left and right sides of the rat posterior cricoarytenoid (PCA), lateral thyroarytenoid (LTA), and medial thyroarytenoid (MTA), respectively. After high-throughput RNA-Sequencing, 88 samples were organized into 12 datasets according to their age (P15/adult), sex (male/female), and muscle type (PCA/LTA/MTA). A comprehensive bioinformatics analysis was conducted to compare the left-right ILMs across different conditions. RESULTS: A total of 774 differentially expressed genes were identified across the 12 experimental groups, revealing age, sex, and muscle-specific differences between the left versus right ILMs. Enrichment analysis of Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathways implicated several genes with a left-right laryngeal muscle asymmetry. These genes are associated with neuronal and muscular physiology, immune/inflammatory response, and hormone control. CONCLUSION: Bioinformatics analysis confirmed divergent transcriptome profiles between the left-right ILMs. This preliminary study identifies putative gene targets that will characterize ILM laterality. LEVEL OF EVIDENCE: N/A Laryngoscope, 2024.

Optical Flow Analysis of Paralaryngeal Muscle Movement.

OBJECTIVES: The paralaryngeal muscles are thought to be hyperfunctional with phonation in patients with primary muscle tension dysphonia (pMTD). However, objective, quantitative tools to assess paralaryngeal movement patterns lack. The objectives of this study were to (1) validate the use of optical flow to characterize paralaryngeal movement patterns with phonation, (2) characterize phonatory optical flow velocities and variability of the paralaryngeal muscles before and after a vocal load challenge, and (3) compare phonatory optical flow measures to standard laryngoscopic, acoustic, and self-perceptual assessments. METHODS: Phonatory movement velocities and variability of the paralaryngeal muscles at vocal onsets and offsets were quantified from ultrasound videos and optical flow methods across 42 subjects with and without a diagnosis of pMTD, before and after a vocal load challenge. Severity of laryngoscopic mediolateral supraglottic compression, acoustic perturbation, and ratings of vocal effort and discomfort were also obtained at both time points. RESULTS: There were no significant differences in optical flow measures of the paralaryngeal muscles with phonation between patients with pMTD and controls. Patients with pMTD had significantly more supraglottic compression, higher acoustic perturbations, and higher vocal effort and vocal tract discomfort ratings. Vocal load had a significant effect on vocal effort and discomfort but not on supraglottic compression, acoustics, or optical flow measures of the paralaryngeal muscles. CONCLUSION: Optical flow methods can be used to study paralaryngeal muscle movement velocity and variability patterns during vocal productions, although the role of the paralaryngeal in pMTD diagnostics (e.g., vocal hyperfunction) remains suspect. LEVEL OF EVIDENCE: 2 Laryngoscope, 134:1792-1801, 2024.

MYH13, a superfast myosin expressed in extraocular, laryngeal and syringeal muscles.

MYH13 is a unique type of sarcomeric myosin heavy chain (MYH) first detected in mammalian extraocular (EO) muscles and later also in vocal muscles, including laryngeal muscles of some mammals and syringeal muscles of songbirds. All these muscles are specialized in generating very fast contractions while producing relatively low force, a design appropriate for muscles acting against a much lower load than most skeletal muscles inserting into the skeleton. The definition of the physiological properties of muscle fibres containing MYH13 has been complicated by the mixed fibre type composition of EO muscles and the coexistence of different MYH types within the same fibre. A major advance in this area came from studies on isolated recombinant myosin motors and the demonstration that the affinity of actin-bound human MYH13 for ADP is much weaker than those of fast-type MYH1 (type 2X) and MYH2 (type 2A). This property is consistent with a very fast detachment of myosin from actin, a major determinant of shortening velocity. The MYH13 gene arose early during vertebrate evolution but was characterized only in mammals and birds and appears to have been lost in some teleost fish. The MYH13 gene is located at the 3' end of the mammalian fast/developmental gene cluster and in a similar position to the orthologous cluster in syntenic regions of the songbird genome. MYH13 gene regulation is controlled by a super-enhancer in the mammalian locus and deletion of the neighbouring fast MYH1 and MYH4 genes leads to abnormal MYH13 expression in mouse leg muscles.

Differences between the Perilaryngeal Pressure Pain Thresholds in Asymptomatic Women, Women With Bruxism, and Women With Odynophonia.

OBJECTIVE: This study was aimed at comparing perilaryngeal pressure pain thresholds (PPT) among asymptomatic women, women with bruxism, and women with odynophonia. DESIGN: Observational cross-sectional study. METHODS: Eighty-four women whose age mean was 23.75 (SD, 3.02) years were grouped according to inclusion and exclusion criteria into a group of asymptomatic women (G1), another group of women with bruxism (G2), and another of women with odynophonia (G3). Palpation was used to identify regions of interest for this study, and an analog algometer was used to evaluate perilaryngeal PPT in the previously localized regions. Each PPT evaluation was done twice. RESULTS: G1 PPT mean were between 1.35 (SD, 0.20) and 2.29 (SD, 0.28) kg/cm2, G2 PPT mean were found between 0.85 (SD, 0.12) and 1.78 (SD, 0.23) kg/cm2, and G3 PPT mean were located between 0.71 (SD, 0.11) and 1.45 (SD, 0.19) kg/cm2. Differences were observed between PPT in the three groups evaluated (P < 0.05). The intra-evaluator agreement between the evaluations performed fluctuated between 60.71% (κ = 0.51) and 92.86% (κ = 0.91). CONCLUSIONS: There are significant differences between the perilaryngeal PPT of asymptomatic women, women with bruxism, and women with odynophonia. Asymptomatic women had the highest PPT, while odynophonia sufferers had the lowest.

Use of Motion Capture Technology to Study Extrinsic Laryngeal Muscle Tension and Hyperfunction.

OBJECTIVES: Patients with primary muscle tension dysphonia (pMTD) commonly report paralaryngeal pain and discomfort, and extrinsic laryngeal muscle (ELM) tension and hyperfunction are commonly implicated. However, quantitative physiological metrics to study ELM movement patterns for the characterization of pMTD diagnosis and monitoring of treatment progress are lacking. The objectives of this study were to validate motion capture (MoCap) technology to study ELM kinematics, determine whether MoCap could distinguish ELM tension and hyperfunction between individuals with and without pMTD, and investigate relationships between common clinical voice metrics and ELM kinematics. METHODS: Thirty subjects (15 with pMTD and 15 controls) were recruited for the study. Sixteen markers were placed on different anatomical landmarks on the chin and anterior neck. Movements across these regions were tracked during four voice and speech tasks using two three-dimensional cameras. Movement displacement and variability were determined based on 16 key-points and 53 edges. RESULTS: Intraclass correlation coefficients demonstrated high intra- and inter-rater reliability (p's < 0.001). Other than greater movement displacements around the thyrohyoid space during longer phrasing (reading passage, 30-s diadochokinetics) and more movement variability in patients with pMTD, kinematic patterns between groups were similar across the 53 edges for the four voice and speech tasks. There were also no significant correlations between ELM kinematics and standard voice metrics. CONCLUSION: Results demonstrate the feasibility and reliability of MoCap for the study of ELM kinematics. LEVEL OF EVIDENCE: 3 Laryngoscope, 133:3472-3481, 2023.

Modeling the influence of the extrinsic musculature on phonation.

Neck muscles play important roles in various physiological tasks, including swallowing, head stabilization, and phonation. The mechanisms by which neck muscles influence phonation are not well understood, with conflicting reports on the change in fundamental frequency for ostensibly the same neck muscle activation scenarios. In this work, we introduce a reduced-order muscle-controlled vocal fold model, comprising both intrinsic muscle control and extrinsic muscle effects. The model predicts that when the neck muscles pull the thyroid cartilage in the superior-anterior direction (with a sufficiently large anterior component), inferior direction, or inferior-anterior direction, tension in the vocal folds increases, leading to fundamental frequency rise during sustained phonation. On the other hand, pulling in the superior direction, superior-posterior direction, or inferior-posterior direction (with a sufficiently large posterior component) tends to decrease vocal fold tension and phonation fundamental frequency. Varying the pulling force location alters the posture and phonation biomechanics, depending on the force direction. These findings suggest potential roles of particular neck muscles in modulating phonation fundamental frequency, with implications for vocal hyperfunction.

Surface electromyographic (sEMG) activity of the suprahyoid and sternocleidomastoid muscles in pitch and loudness control.

Purpose: This study set out to determine the contributions of the suprahyoid and sternocleidomastoid (SCM) muscles in changing pitch and loudness during phonation among vocally healthy populations. Method: Thirty-nine participants were first recruited, and twenty-nine of them who passed the screening test (Voice Handicap Index [VHI]-10 score ≤11, auditory-perceptual voice rating score ≤2) were finally selected (mean age = 28.2 years). All participants were measured for their surface electromyographic (sEMG) activity collected from the bilateral suprahyoid and SCM muscles when producing the vowel /a/, /i/, and /u/ in natural (baseline) and at different pitch (+3, +6, -3, -6 semitones) and loudness (+5, +10, -5 dB) levels. Linear mixed-effects models were performed to determine the influencing factors on the root-mean-square percentage of maximal voluntary contraction (RMS %MVC) value of the sEMG signals. Results: Compared with the baseline, a significant decrease of RMS %MVC was found in the suprahyoid muscles during overall phonations of lower pitches (-3 and -6 semitones) and loudness (-5 dB). However, no significant change was detected when producing speech at higher pitch (+3 and +6 semitones) and loudness (+5 and +10 dB) levels. Among the three vowels, /i/ demonstrated significantly higher RMS %MVC than those of /a/ and /u/. The SCM muscles, however, did not show any significant change in the RMS %MVC values among different vowels in relation to the pitch and loudness changes. When the muscles were compared across the two sides, significantly higher RMS %MVC was found in the right side of the suprahyoid (in pitch and loudness control) and SCM (in pitch control) when compared to the left side. Conclusions: The suprahyoid muscle activities were significantly decreased when producing lower pitches and intensities compared to the natural baselines. The production of sustained /i/ required significantly more suprahyoid muscle activities than those of /a/ and /u/. The SCM muscles did not show much sEMG activity in any of the pitch and loudness levels, which could be used potentially as the calibration or normalization of peri-laryngeal sEMG measurement. The findings also showed a tendency for bilateral asymmetry in the use of suprahyoid and SCM muscles.

Immediate Effects of Semi-occluded Vocal Tract Exercises as a Vocal Warm-Up in Singers.

OBJECTIVE: The present study aimed to investigate the Immediate Effects of Semi-occluded Vocal Tract Exercises (SOVTEs) as a vocal warm-up on the Electrical Activity of Extrinsic Laryngeal Muscles and acoustic parameters of voice in singers. STUDY DESIGN: This study used a pre-/post-interventional (quasi-experimental) design and a simple non-random sampling method. SETTING: Musculoskeletal Rehabilitation Research Center. METHOD: Surface electromyography of the suprahyoid and infrahyoid muscle areas and acoustic measurements were assessed before and immediately after performing three SOVTEs: lip-trill, humming, and straw phonation for 20 minutes as a vocal warm-up in eleven healthy male singers with an average age of 26.5 ± 4.2. RESULTS: After performing the vocal warm-up, root mean square in channels two and three (left and right infrahyoid muscle areas) in all vocal tasks, including /i/, /u/, and counting from 20 to 30 was significantly decreased (P < 0.05). The acoustic parameters, F1, and F1-F0 difference were significantly decreased (P < 0.05). CONCLUSION: The results suggest that after performing SOVTEs as a vocal warm-up, the electrical activity of the extrinsic laryngeal muscles is reduced. The acoustic analysis also demonstrated a decrease in F0, F1, and F1-F0 variables. Therefore, it seems that the results of acoustic and electromyographic assessments are in line and it is likely that SOVTEs through the vocal economy lead to a reduction in the load applied to the phonatory system.

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.

Control of Pre-phonatory Glottal Shape by Intrinsic Laryngeal Muscles.

OBJECTIVES: Surgical manipulations to treat glottic insufficiency aim to restore the physiologic pre-phonatory glottal shape. However, the physiologic pre-phonatory glottal shape as a function of interactions between all intrinsic laryngeal muscles (ILMs) has not been described. Vocal fold posture and medial surface shape were investigated across concurrent activation and interactions of thyroarytenoid (TA), cricothyroid (CT), and lateral cricoarytenoid/interarytenoid (LCA/IA) muscles. STUDY DESIGN: In vivo canine hemilarynx model. METHODS: The ILMs were stimulated across combinations of four graded levels each from low-to-high activation. A total of 64 distinct medial surface postures (4 TA × 4 CT × 4 LCA/IA levels) were captured using high-speed video. Using a custom 3D interpolation algorithm, the medial surface shape was reconstructed. RESULTS: Combined activation of ILMs yielded a range of unique pre-phonatory postures. Both LCA/IA and TA activation adducted the vocal fold but with greater contribution from TA. The transition from a convergent to a rectangular glottal shape was primarily mediated by TA muscle activation but LCA/IA and TA together resulted in a smooth rectangular glottis compared to TA alone, which caused rectangular glottis with inferomedial bulging. CT activation resulted in a lengthened but slightly abducted glottis. CONCLUSIONS: TA was primarily responsible for the rectangular shape of the adducted glottis with synergistic contribution from the LCA/IA. CT contributed minimally to vocal fold medial shape but elongated the glottis. These findings further refine laryngeal posture goals in surgical correction of glottic insufficiency. LEVEL OF EVIDENCE: NA, Basic science Laryngoscope, 133:1690-1697, 2023.

Tipos de fibras de los músculos intrínsecos laríngeos de seres humanos: una revisión de la literatura / Fiber types in human intrinsic laryngeal muscles: a literature review

El estudio de las fibras musculares permite comprender con mejor detalle la composición de los músculos y sus características funcionales. Además, facilita la aplicación de programas de entrenamiento y rehabilitación basados en las vías energéticas que regulan la contracción muscular. Su estudio generalmente va unido al análisis de las cadenas pesadas de miosina (MyHC), las que informan sobre las características y propiedades funcionales del músculo. El objetivo de este trabajo fue sintetizar la evidencia científica disponible sobre la distribución de fibras musculares y de isoformas de cadenas pesadas de miosina de los músculos intrínsecos de la laringe de seres humanos. Se realizó una revisión sistemática de la literatura mediante el análisis de artículos encontrados en las bases de datos PubMed, EBSCOHost y SciELO. Los hallazgos informan sobre la existencia de fibras tónicas lentas y tipo I, II, IIA y IIX/IIB. Además, se reconoce la presencia de las isoformas MyHC-I, MyHC-IIA, MyHC-IIX, MyHC-Fetal, MyHC-L y MyHC-IIB. En conclusión, los músculos intrínsecos de la laringe presentan una mezcla de fibras y de isoformas de MyHC lentas y rápidas,la que obedece a adaptaciones y cambios evolutivos que han permitido, por ejemplo, las características fonatorias que presenta la voz del ser humano.

The study of muscle fibers allows the composition of muscles and their functional characteristics to be understood in greaterdetail. In addition, it makes it possible to applytraining and rehabilitation programs based on the energypathways that regulatemuscle contraction. Studying muscle fibers is generally associated withthe analysis of myosin heavy chains (MHC) which provide information on the functional characteristics and properties of muscles. The objective of this study was to synthesize the available scientific evidence onthe distribution of muscle fibers and myosin heavy chain isoforms present in the intrinsic laryngeal muscles of human beings. A systematic reviewof the literature was carried outand articles found on PubMed, EBSCOHost,and SciELOwere analyzed.The findings showthe presenceof slow-tonic, type I, type II, type IIA, and type IIX/IIB fibers. Additionally,isoforms MHC-I, MHC-IIA, MHC-IIX, MHC-Fetal, MHC-L, and MHC-IIB canbe found. In conclusion, intrinsic laryngeal muscles are composed ofa combination of slow and fast fibers and MHC isoforms, derived from evolutionary adaptations and changes which have given way, among other things, to the phonetic characteristics ofthe human voice.

Proteomic Characterization of Senescent Laryngeal Adductor and Plantaris Hindlimb Muscles.

OBJECTIVES: The goals of this study were to 1) compare global protein expression in muscles of the larynx and hindlimb and 2) investigate differences in protein expression between aged and nonaged muscle using label-free global proteomic profiling methods. METHODS: Liquid chromatography-mass spectrometry (LC-MS/MS) analysis was performed on thyroarytenoid intrinsic laryngeal muscle and plantaris hindlimb muscle from 10 F344xBN F1 male rats (5 old and 5 young). Protein expression was compared and pathway enrichment analysis performed for each muscle type (larynx and limb) and age group (old and young muscle). RESULTS: Over 1,000 proteins were identified in common across both muscle types and age groups using LC-MS/MS analysis. Significant age-related differences were seen across 107 proteins in plantaris hindlimb and in 19 proteins in thyroarytenoid laryngeal muscle. Bioinformatic and enrichment analysis demonstrated protein differences between the hindlimb and larynx may relate to immune and stress redox responses and RNA repair. CONCLUSION: There are clear differences in protein expressions between the laryngeal and hindlimb skeletal muscles. Initial analysis suggests differences between the two muscle groups may relate to stress responses and repair mechanisms. Age-related changes in the thyroarytenoid appear to be less obvious than in the plantaris. Further in-depth study is needed to elucidate how aging affects protein expression in the laryngeal muscles. LEVEL OF EVIDENCE: NA Laryngoscope, 132:148-155, 2022.

Laryngeal Findings in Duchenne Muscular Dystrophy.

INTRODUCTION: Some studies have demonstrated that the intrinsic muscles of the larynx show no signs of damage to the muscle fiber and raise a possibility of preservation of the laryngeal muscles in muscular dystrophies. A cross-sectional study was implemented with a case series of patients with Duchenne muscular dystrophy. METHODS: This study was carried out through a medical assessment through anamnesis and medical records, perceptual-auditory evaluation of the voice in 15 patients, and videolaryngoscopic evaluation in 11 patients. RESULTS: All patients had the maximum phonation time of the vowel /e/ decreased, 7 (46.7%) had reduced loudness while 10 (66.7%) had vocal asthenia. There were no changes in muscular tone and mobility in the videolaryngoscopy. DISCUSSION: Patients with Duchene muscular dystrophy do not present abnormalities suggestive of the involvement of the intrinsic muscles of the larynx but have vocal worsening due to pulmonary impairment.

Exercise Science and the Vocalist.

The application of exercise science training knowledge has been of growing interest to voice professionals. This tutorial, derived from the authors' invited presentations from the "Exercise and the Voice" Special Session at the 2018 Voice Foundation Symposium, proposes a foundational theoretical structure based in exercise science, clarifies the wide range of variables that may influence voice training, and summarizes our present understanding of voice physiology from the perspective of muscle training. The body of literature on voice exercise was then analyzed from the perspective of this framework, identifying what we currently know and what we still have yet to learn.

Subjective voice analysis in patients with muscular tension dysphonia: comparison between clinician and patient evaluation.

BACKGROUND: This study evaluated the correlation between patient and clinician subjective voice analysis in a group of patients suffering from muscular tension dysphonia. This disease does not usually present with organic lesions, and voice analysis is crucial to evaluate it. METHODS: A retrospective study with 75 patients was performed. Correlation between grade, roughness, breathiness, asthenia and strain scale and voice handicap index-10 was analysed. Any possible influence of the type of muscular tension dysphonia on these two scales was studied. RESULTS: There are only a few studies that correlate voice handicap index-10 and the grade, roughness, breathiness, asthenia and strain scale; however, none of them are specific for patients suffering from muscular tension dysphonia. A moderate correlation (r = 0.56) was found. No influence of muscular tension dysphonia type on voice handicap index-10 score was found, but muscular tension dysphonia type 4 had worse grade, roughness, breathiness, asthenia and strain scale scores than other muscular tension dysphonia types. This could be explained if muscular tension dysphonia type 4 is considered to be the most severe form of this disease. CONCLUSION: The use of assessment scales based on the opinion of both the clinician and patient must be considered as complementary clinical tools in order to perform a complete assessment of dysphonia.

Arytenoid asymmetry: Is it the most predictive parameter for arytenoid adduction in unilateral vocal fold paralysis?

OBJECTIVE: The aim of this study was to establish arytenoid asymmetry as a pre-operative predictive parameter for arytenoid adduction surgery in unilateral vocal fold paralysis and thereafter identify the most predictive parameter for arytenoid adduction among the established parameters. METHODS: A retrospective comparative study was undertaken. The 'arytenoid asymmetry angle' formed between skewed 'glottic' and 'interarytenoid' axes (traced along the plane of closure of the membranous and cartilaginous glottis, respectively) was quantified in pre-operative laryngoscopic images of 85 adults with unilateral vocal fold paralysis who underwent either type 1 thyroplasty (group 1) or type 1 thyroplasty with arytenoid adduction (group 2). The need for arytenoid adduction was determined intra-operatively based on subjective voice improvement and laryngoscopic results. RESULTS: Arytenoid asymmetry (p < 0.0001), posterior phonatory gap (p = 0.001) and vertical level difference (p = 0.004) were significantly greater in group 2 (descending order of parameters). Arytenoid asymmetry angle showed a significant positive correlation with the latter two parameters. CONCLUSION: Arytenoid asymmetry is the most predictive parameter for arytenoid adduction. An arytenoid asymmetry angle of more than or equal to 33.9° is an indication for arytenoid adduction. This aids in pre-operative planning of arytenoid adduction.

Exercise Science and the Vocalist.

The application of exercise science training knowledge has been of growing interest to voice professionals. This tutorial, derived from the authors' invited presentations from the "Exercise and the Voice" Special Session at the 2018 Voice Foundation Symposium, proposes a foundational theoretical structure based in exercise science, clarifies the wide range of variables that may influence voice training, and summarizes our present understanding of voice physiology from the perspective of muscle training. The body of literature on voice exercise was then analyzed from the perspective of this framework, identifying what we currently know and what we still have yet to learn.

Multiparametric laryngeal assessment of the effect of thalamic deep brain stimulation on essential vocal tremor.

OBJECTIVE: EVT is a refractory voice disorder that significantly affects quality of life. This work aims to conduct a multiparametric assessment of the effect of deep brain stimulation (DBS) of the thalamic ventral intermediate nucleus (VIM) on essential vocal tremor (EVT) and investigate the relation between DBS lead location and EVT outcomes. METHODS: Nine participants underwent DBS for essential tremor and were diagnosed with co-occurring EVT in this prospective cohort study. Objective measurements including acoustic evaluation of vocal fundamental frequency (F0) and intensity modulation and subjective measurements including physiologic evaluation of the oscillatory movement of the laryngeal muscles and vocal tract and perceptual ratings of tremor severity were collected PRE and POST DBS. Finally, we investigated the relation between DBS lead location and EVT outcomes. RESULTS: Acoustic modulations of F0 and intensity were significantly improved POST DBS. Physiologic assessment showed a POST DBS reduction of oscillatory movement in the laryngeal muscles and vocal tract, but not significantly. Listener and participant perception, of EVT severity was also significantly reduced. Finally, our results indicate better EVT control with increased distance to midline of left VIM thalamic stimulation. CONCLUSIONS: By employing a battery of objective and subjective measures, our study supports the benefit of DBS for the treatment of EVT and specifies the acoustic and physiologic mechanisms that mediate its positive effect. We further provide preliminary results on the relation between lead location and EVT outcomes, laying the foundation for future studies to clarify the optimal DBS target for the treatment of EVT.