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Purpose: The purpose of this tutorial is threefold: (a) present relevant exercise science literature on skeletal muscle metabolism and synthesize the limited available research on metabolism of the adult human speech musculature in an effort to elucidate the role of metabolism in speech production; (b) introduce a well-studied metabolic serum biomarker in exercise science, lactate, and the potential usefulness of investigating this metabolite, through a well-established exercise science methodology, to better understand metabolism of the musculature involved in voice production; and (c) discuss exercise physiology considerations for future voice science research that seeks to investigate blood lactate and metabolism in voice physiology in an ecologically valid manner., Method: This tutorial begins with relevant exercise science literature on the basic cellular processes of muscle contraction that require energy and the metabolic mechanisms that regenerate the energy required for task execution. The tutorial next synthesizes the available research investigating metabolism of the adult human speech musculature. This is followed by the authors proposing a hypothesis of speech metabolism based on the voice science literature and the application of well-studied exercise science principles of muscle physiology. The tutorial concludes with a discussion and the potential usefulness of lactate in investigations to better understand the metabolism of the musculature involved in vocal demand tasks., Conclusion: The role of metabolism during speech (respiratory, laryngeal, and articulatory) is an understudied yet critical aspect of speech physiology that warrants further study to better understand the metabolic systems that are used to meet vocal demands.

The purpose of this investigation was to observe laryngeal tissue and vocal function changes over the course of 28 days in a single participant diagnosed by a laryngologist with bilateral nodules. Laryngeal imaging, acoustic variables and perceptual assessments of voice quality, and perceived vocal effort were obtained every morning for 28 consecutive days. A daily journal of occupational and recreational voice use as well as menstruation and alcohol consumption was maintained each day. It was hypothesized that the laryngeal pathology would appear more extensive and the vocal function measures obtained would be worse following extensive voice use. Laryngeal imaging, acoustic variables, and perceptual measures quantified provided evidence to support the study hypotheses. The size, extent, and asymmetry of the bilateral vocal pathologies observed were more extensive on days following occupational and recreational vocal loading. Acoustic and perceptual measures obtained correlated with the laryngeal tissue changes observed. Study findings support a more holistic approach to laryngeal pathology diagnosis that is based on a more thorough understanding of vocal loading considerations up to 48 hours prior to laryngeal endoscopy to better understand the pathophysiology of the observed lesion(s) for most accurate clinical diagnosis., (Copyright © 2020 The Voice Foundation. Published by Elsevier Inc. All rights reserved.)

Purpose The aim of this study was to examine the influence of menstrual cycle phases (follicular, ovulatory, luteal, and ischemic) and hormone levels (estradiol, testosterone, progesterone, and neuropeptide Y) on vocal fold vibrations in reproductive and postmenopausal women. Method Glottal area waveforms were extracted from high-speed videoendoscopy during sustained phonation, inhalation phonation, and voice onset/offset in the reproductive ( n = 15) and postmenopausal ( n = 13) groups. Linear mixed-model analysis was conducted to evaluate hormone levels and high-speed videoendoscopy outcome variables between the reproductive and postmenopausal groups. In the reproductive group, simple linear regression and multiple regression were conducted to determine the effects of hormones on the dependent variables. Results Group differences between reproductive and postmenopausal women were identified for stiffness index, oscillatory onset time, and oscillatory offset time. Neuropeptide Y hormone in the ischemic phase significantly predicted changes in the reproductive group for some dependent variables; however, the relationship varied for sustained phonation and inhalation phonation. Conclusion These findings provide preliminary evidence that vocal fold vibrations in the reproductive group are different predominantly in the ischemic phase due to neuropeptide Y changes.

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., (Copyright © 2019 The Voice Foundation. Published by Elsevier Inc. All rights reserved.)

The purpose of this research was to characterize the voice physiology requirements of indoor cycling instructors as measured by vocal dose (distance the vocal folds travel and average voice intensity) and perceived phonatory effort with and without amplification. Using a within-participant repeated measures design, eight rhythm-based cycling instructors were consented and scheduled to teach two ecologically valid cycling fitness classes, one amplified and one without amplification. Objective measures included vocal dosimetry and ambient sound level. Perceived phonatory effort and participant demographic information were also collected. Trials were counterbalanced to avoid an order effect. Data analyses indicated a significant difference in perceived phonatory effort between trials (P = 0.005) with the amplified trial resulting in a lower effort. Statistically significant differences between vocal distance dose were not found, with an unexpected finding of increased distance dose with use of amplification. Average voice intensity for female participants was 99.6 dB with amplification and 96.1 dB without amplification. This investigation highlights the importance of occupation specific study of voice use requirements and the difficulty in generalizing the findings from one occupational voice user group to another., (Copyright © 2019 The Voice Foundation. Published by Elsevier Inc. All rights reserved.)

Purpose The purpose of this preliminary study was to identify a vocal task that could be used as a clinical indicator of the vocal aptitude or vocal fitness required for vocally demanding occupations in a manner similar to that of the anaerobic power tests commonly used in exercise science. Performance outcomes for vocal tasks that require rapid acceleration and high force production may be useful as an indirect indicator of muscle fiber complement and bioenergetic fitness of the larynx, an organ that is difficult to study directly. Method Sixteen women (age range: 19-24 years, M = 22 years) were consented for participation and completed the following performance measures: forced vital capacity, three adapted vocal function tasks, and the horizontal sprint test. Results Using a within-participant correlational analyses, results indicated a positive relationship between the rate of the last second of a laryngeal diadochokinesis task that was produced at a high fundamental frequency/high sound level and anaerobic power. Forced vital capacity was not correlated with any of the vocal function tasks. Conclusions These preliminary results indicate that aspects of the laryngeal diadochokinesis task produced at a high fundamental frequency and high sound level may be useful as an ecologically valid measure of vocal power ability. Quantification of vocal power ability may be useful as a vocal fitness assessment or as an outcome measure for voice rehabilitation and habilitation for patients with vocally demanding jobs.age = 22 years) were consented for participation and completed the following performance measures: forced vital capacity, three adapted vocal function tasks, and the horizontal sprint test. Results Using a within-participant correlational analyses, results indicated a positive relationship between the rate of the last second of a laryngeal diadochokinesis task that was produced at a high fundamental frequency/high sound level and anaerobic power. Forced vital capacity was not correlated with any of the vocal function tasks. Conclusions These preliminary results indicate that aspects of the laryngeal diadochokinesis task produced at a high fundamental frequency and high sound level may be useful as an ecologically valid measure of vocal power ability. Quantification of vocal power ability may be useful as a vocal fitness assessment or as an outcome measure for voice rehabilitation and habilitation for patients with vocally demanding jobs.

Purpose To assess data collection variability in the voice range profile (VRP) across clinicians and researchers, a systematic review was conducted to evaluate the extent of variability of specific data collection points that affect the determination of frequency range and sound level and determine next steps in standardization of a VRP protocol. Method A systematic review was conducted using the Preferred Reporting Items for Systematic Review and Meta-Analysis checklist. Full-text journal articles were identified through PubMed, Web of Science, Psych Info, ProQuest Dissertations and Theses Global, Google Scholar, and hand searching of journals. Results A total of 1,134 articles were retrieved from the search; of these, 463 were duplicates. Titles and abstracts of 671 articles were screened, with 202 selected for full-text review. Fifty-four articles were considered eligible for inclusion. The information extracted from these articles revealed the methodology used to derive the VRP was extremely variable across the data points selected. Additionally, there were eight common acoustic measures used for statistical analysis described in included studies that were added as a data point. Conclusions The data collection methods for the VRP varied considerably. Standardization of procedures was recommended for clinicians and researchers.

Purpose This preliminary study examined the influence of menstrual cycle phase and hormone levels on acoustic measurements of vocal function in reproductive and postmenopausal females. Mean fundamental frequency (f0), speaking fundamental frequency (Sf0), and cepstral peak prominence (CPP) were evaluated. It was hypothesized that Sf0 and CPP would be lower during the luteal and ischemic phases of the menstrual cycle. Group differences with lower values in postmenopausal females and greater variability in the reproductive females were also hypothesized. Method A mixed factorial analysis of variance was used to examine differences between reproductive and postmenopausal females and the four phases of the menstrual cycle. Separate analyses of variances were implemented for each of the dependent measures. Twenty-eight female participants (15 reproductive cycling, 13 postmenopausal) completed the study. Participants were recorded reading the Rainbow Passage and sustaining the vowel /a/. Mean vocal f0, Sf0, and CPP were determined from the acoustic samples. Blood assays were used to determine estrogen, progesterone, testosterone, and neuropeptide Y levels at four data collection time points. Results Group differences in hormone levels and Sf0 values were established with the postmenopausal group having significantly lower hormone levels and significantly lower Sf0 than the reproductive cycling group across the phases. Analysis of the reproductive group by hormone levels and cycle phase revealed no significant differences for CPP or Sf0 across phases. Higher estrogen was identified in the ovulation phase, and higher progesterone was identified in the luteal phase. Conclusions Significant differences in hormone levels and Sf0 were identified between groups. Within the reproductive cycling group, the lack of significant difference in acoustic measures relative to hormone levels indicated that the measures taken may not have been sensitive enough to identify hormonally mediated vocal function changes. The participant selection may have biased the findings in that health conditions and medications that are known to influence voice function were used as exclusion criteria.

Purpose The purpose of this document is threefold: (a) review the uses of the terms "vocal fatigue," "vocal effort," "vocal load," and "vocal loading" (as found in the literature) in order to track the occurrence and the related evolution of research; (b) present a "linguistically modeled" definition of the same from the review of literature on the terms; and (c) propose conceptualized definitions of the concepts. Method A comprehensive literature search was conducted using PubMed/MEDLINE, Embase, Cochrane Central Register of Controlled Trials, and Scientific Electronic Library Online. Four terms ("vocal fatigue," "vocal effort," "vocal load," and "vocal loading"), as well as possible variants, were included in the search, and their usages were compiled into conceptual definitions. Finally, a focus group of eight experts in the field (current authors) worked together to make conceptual connections and proposed consensus definitions. Results The occurrence and frequency of "vocal load," "vocal loading," "vocal effort," and "vocal fatigue" in the literature are presented, and summary definitions are developed. The results indicate that these terms appear to be often interchanged with blurred distinctions. Therefore, the focus group proposes the use of two new terms, "vocal demand" and "vocal demand response," in place of the terms "vocal load" and "vocal loading." We also propose standardized definitions for all four concepts. Conclusion Through a comprehensive literature search, the terms "vocal fatigue," "vocal effort," "vocal load," and "vocal loading" were explored, new terms were proposed, and standardized definitions were presented. Future work should refine these proposed definitions as research continues to address vocal health concerns.

Objectives/hypotheses: Principles from exercise science literature were applied to singing warm-up pedagogy as a method for examining parallels between athletic and voice training. Analysis of the use of exercise principles in vocal warm-up should illuminate aspects of voice training that may be further developed in the future., Methods/design: A selected canon of standard voice pedagogy texts and well-regarded warm-up methods were evaluated for use of exercise science principles for skill acquisition and fatigue resistance. Exercises were then categorized according to whether they were used for the purpose of skill acquisition (specificity), training up to tasks (overload), or detraining (reversibility)., Results: A preliminary review of well-established voice pedagogy programs reveals a strong bias toward the skill acquisition aspects of vocal warm-up, with little commentary on the fatigue management aspects. Further, the small number of vocalises examined that are not skill-acquisition oriented fall into a third "habilitative" category that likewise does not relate to overload but may play a role in offsetting reversibility., Conclusions: Although a systematic pedagogy for skill acquisition has emerged in the literature and practice of voice pedagogy, a parallel pedagogy for fatigue management has yet to be established. Identification of a systematic pedagogy for training up to specific singing genres and development of a singing maintenance program to avoid detraining may help the singer avoid injury., (Copyright © 2018 The Voice Foundation. Published by Elsevier Inc. All rights reserved.)

Purpose: Translating exercise-science methodology for determination of muscle bioenergetics, we hypothesized that the temporal voice-use patterns for classroom and music teachers would indicate a reliance on the immediate energy system for laryngeal skeletal-muscle metabolism. It was hypothesized that the music-teacher group would produce longer voiced segments than the classroom teachers., Method: Using a between- and within-group multivariate analysis-of-variance design (5 classroom teachers; 7 music teachers), we analyzed fundamental-frequency data-collected via an ambulatory phonation monitor-for length (seconds) of voiced and nonvoiced intervals. Data were collected for 7.5 hr during the workday, over the course of several workdays for each teacher., Results: Descriptive analyses of voiced and nonvoiced intervals indicated that over 99% of voiced segments for both groups were no longer than 3.15 s, supporting the hypothesis of reliance on the immediate energy system for muscle bioenergetics. Significant differences were identified between and within the classroom- and music-teacher groups, with the music-teacher group producing longer voiced segments overall., Conclusions: Knowledge of probable intrinsic laryngeal skeletal-muscle bioenergetics requirements could inform new interdisciplinary considerations for voice habilitation and rehabilitation.

Purpose: The purpose of this study was to examine the influence of the heating, ventilation, and air-conditioning method on voice function following a voicing task using ecologically valid offices, one with radiant HVAC and one with forced air., Method: A total of 12 consented participants (6 women, 6 men) narrated a video in each of 4 environmental conditions in a within-between repeated-measures design. Acoustic data were collected with an ambulatory phonation monitor and perceived phonatory effort was determined following the voicing task. Data were analyzed using a within-between repeated-measures analysis of variance with significance set at α < .05., Results: Perceived phonatory effort did not differ between environments; however, a significant difference in vocal amplitude between 2 trials was identified for the male participants and physiologically significant differences in vocal amplitude were identified for male and female participants., Conclusions: The findings suggest that perceived phonatory effort may not be a sensitive measure of vocal function differences following a voicing task in ecologically valid office spaces despite significant acoustic findings. Future research should address longer exposure to environmental differences combined with a longer voicing task within ecologically valid work spaces as well as the recruitment of participants who have particular vulnerability to environmental perturbations.

Purpose: Phonation threshold pressure and perceived phonatory effort were hypothesized to increase and upper airway temperature to decrease following exposure to cold and/or dry air. Greater changes were expected with mouth versus nose breathing., Method: In a within-participant repeated measures design, 15 consented participants (7 men, 8 women) completed 20-min duration trials to allow for adequate thermal equilibration for both nose and mouth breathing in 5 different environments: 3 temperatures (°C) matched for relative humidity (% RH), cold (15 °C, 40% RH), thermally neutral (25 °C, 40% RH), and hot (35 °C, 40% RH); and 2 temperatures with variable relative humidity to match vapor pressure for the neutral environment (25 °C, 40% RH), cold (15 °C, 74% RH) and hot (35 °C, 23% RH). Following each equilibration trial, measures were taken in this order: upper airway temperature (transnasal thermistor probe), phonation threshold pressure, and perceived phonatory effort., Results: Data were analyzed using repeated measures analysis of variance, and no significant differences were established., Conclusions: The study hypotheses were not supported. Findings suggest that the upper airway is tightly regulated for temperature when challenged by a realistic range of temperature and relative humidity environments. This is the first study of its kind to include measurement of upper airway temperature in conjunction with measures of vocal function.

Objectives/hypothesis: There is little known about how physical exercise may alter physiological parameters of voice production. In this investigation, vocal function and upper airway temperature were examined following a bout of submaximal exercise and compared with a resting breathing condition. It was hypothesized that phonation threshold pressure (PTP) and perceived phonatory effort (PPE) would increase and pharyngeal temperature would decrease following an exercise bout., Study Design: Using a within-participant repeated measures design, 18 consented participants (nine men and nine women) completed the study., Methods: A 20-minute equilibration task was immediately followed by 8 minutes of submaximal exercise on a stationary bike in a thermally neutral environment (25°C/40% RH). At the end of the equilibration trial and the exercise trial, measures were taken in the following order: pharyngeal temperature, PTP, and PPE. Data were analyzed using paired t tests with significance set at P < 0.05., Results: Significantly increased PTP and PPE and significantly decreased pharyngeal temperature (1.9°C) were found, supporting the initial hypotheses., Conclusions: Findings from this investigation support the widely held belief that voice use associated with physical activity requires additional laryngeal effort and closure forces. The effect of the temperature reduction in the upper airway on voice function requires further study., (Copyright © 2013 The Voice Foundation. Published by Mosby, Inc. All rights reserved.)