Analysis of vocal abuse: fluctuations in phonation time and intensity in 4 groups of speakers

Quantifying the Occupational Voice Use of Teachers

Purpose

The teaching profession is a high-voice use occupation at elevated risk for developing voice disorders. Continued research on teachers' vocal demands is necessary to advocate for and establish vocal health programs. This study quantified ambulatory vocal dose measures for teachers during both on- and off-work periods, comparing their occupational voice use to that in other studies that have reported percent phonation ranging from 17% to 30%.

Method

Participants included 26 full-time, female school teachers between 23 and 55 years of age across multiple grades and subjects, including individuals with and without a voice disorder. Ambulatory voice data were collected from weeklong voice monitoring that recorded phonatory activity through anterior neck-surface vibration. Three vocal dose measures-time, cycle, and distance doses-were computed for each participant for three time periods: on-work weekdays, off-work weekdays, and off-work weekend days.

Results

The teachers' average percent phonation was 16.2% on-work weekdays, 8.4% off-work weekdays, and 8.0% off-work weekend days. No statistically significant differences for vocal dose measures were found between off-work weekdays and weekend days. Overall, all vocal dose measures were approximately 2 times higher during work relative to off-work time periods.

Conclusions

This study provides values for vocal dose measures for school teachers using ambulatory voice-monitoring technology. The vocal demands of this particular teacher sample and voice activity detection algorithm are potential factors contributing to percent phonation values on the lower end of the range reported in the literature. Future work is needed to continue to understand occupational voice use and its associated risks related to voice health, with the ultimate goal of preventing and managing voice disorders in individuals engaged in high-risk occupations.

Do-It-Yourself Voice Dosimeter Device: A Tutorial and Performance Results

PURPOSE

Voice dosimeters gather voice production data in the daily lives of individuals with voice disorders. Additionally, voice dosimeters aid in understanding the pathophysiology of voice disorders. Previously, several voice dosimeters were commercially available. However, these devices have been discontinued and are not available to clinicians and researchers alike. In this tutorial, instructions for a low-cost, easy-to-assemble voice dosimeter are provided. This do-it-yourself (DIY) voice dosimeter is further validated based on performance results.

METHOD

Ten vocally healthy participants wore the DIY voice dosimeter. They produced a sustained /a/ vowel and read a text with three different vocal efforts. These tasks were recorded by the DIY voice dosimeter and a reference microphone simultaneously. The expanded uncertainty of the mean error in the estimation of four voice acoustic parameters as measured by the DIY dosimeter was performed by comparing the signals acquired through the reference microphone and the dosimeter.

RESULTS

For measures of sound pressure level, the DIY voice dosimeter had a mean error of -0.68 dB with an uncertainty of 0.56 dB. For fundamental frequency, the mean error was 1.56 Hz for female participants and 1.11 Hz for male participants, with an uncertainty of 0.62 Hz and 0.34 Hz for female and male participants, respectively. Cepstral peak prominence smoothed and L₁ minus L₂ had mean errors (uncertainty) of -0.06 dB (0.27 dB) and 2.20 dB (0.72 dB).

CONCLUSION

The mean error and uncertainties for the DIY voice dosimeter are comparable to those for the most accurate voice dosimeters that were previously on the market.

Introducing a New Dosimeter for the Assessment and Monitoring of Vocal Risk Situations and Voice Disorders

PURPOSE

There are many physiological parameters recorded by devices that are becoming more affordable, precise and accurate. However, the lack of development in the recording of voice parameters from the physiological or medical point of view is striking, given that it is a fundamental tool for the work of many people and given the high incidence and prevalence of voice pathologies that affect people's communication. In this paper we perform a complete literature review on the dosimeters used in voice research and to present a prototype dosimeter with a pilot study to show its capabilities.

METHOD

We conducted a literature review using the keywords [MONITORING], [PHONATION], [ACCUMULATOR], [PORTABLE], [DOSIMETRY], [VOICE] searching in PubMed, Trip Database, HONcode, and SciELO search engines. From our review of dosimeter designs, we created our own prototype consisting of two main components: a Knowles Electronics BU-7135-0000 accelerometer mounted on a neck brace; and the ultra-low power MSP430FR5994 microcontroller. The selected sampling frequency was 2048 Hz. The device calculates the F0 every 250 ms and the amplitude and phonation activity every 31.25 ms. A pilot study was conducted using 2 subjects: one male during 11 days and one female during 14 days.

RESULTS

This work includes devices that have been created during the last 45 years as tools for the diagnosis and monitoring of the treatment of cases of vocal pathology and for the detection of phonatory patterns or risk situations for developing voice disorders or vocal pathologies. We also present recordings with our new device on the pattern of daily talk time, the fundamental frequency and the relative intensity of two subjects on different days.

CONCLUSIONS

Interesting work has been done in the development of voice dosimeters with different approaches. In our experience it is not possible to access them for research and they are not yet in clinical use. It is possible that a joint approach with voice and voice disorders professionals and engineers working closely together could take advantage of current technology to develop a fully portable, useful, and efficient system.

Perception of Primary School Teachers Towards Voice Problems and Vocal Health-Seeking Behaviors: A qualitative study

OBJECTIVE

Teachers are the most common occupational group reporting to the voice clinics with dysphonia across the globe. However, less is known about teachers' perceptions about their voice and voice problems. Hence the present study aimed to explore teachers' perception about their teaching voice, voice problems and vocal health-seeking behaviors.

METHOD

A qualitative phenomenological research design using semi-structured interviews were conducted with fifteen female primary school teachers. Participants were asked to express their perception of teaching voice, vocal health care knowledge, and vocal hygiene practices. Using inductive analysis, the researchers converted the raw data into concepts or themes and discussed.

RESULT

The present study results showed that teachers perceive voice as the primary tool for their profession. However, teachers consider voice problems as part of their professional commitments. Despite knowing the harmful effects of voice problems, teachers' pay less attention to their voice problems and perceive them as usual, unavoidable and part of their profession. Due to their demanding work schedule and not getting enough support from the management, they hesitate to consult medical professionals unless it severely affects them.

CONCLUSIONS

The data obtained from this study can be used to improve the teachers' knowledge regarding vocal health and convince the school management to extend their support for the successful implementation of the vocal health training programs for teachers.

Which teachers are most at risk for voice disorders? Individual factors predicting vocal acoustic parameters monitored in situ during a workweek

PURPOSE

To identify the factors affecting teachers' vocal acoustic parameters, with the aim of detecting individuals at risk of phonotrauma.

METHOD

The voicing time, voice sound pressure level [SPL] and fundamental frequency [f_o] of 87 teachers were measured during one workweek using a voice dosimeter. We retrospectively investigated the impact of 10 factors (gender, age, teaching experience, teaching level, tobacco, gastro-esophageal problems, nonoccupational voice activity, voice education, past voice problems, and biopsychosocial impact of voice problems measured using the Voice Handicap Index [VHI]) on each voice parameter.

RESULTS

None of the above factors affected voicing time or SPL. f_o depended significantly on gender, teaching level, nonoccupational voice activity and VHI score. Specifically, f_o was higher in women (Δ = 69 Hz), in individuals without nonoccupational voice activities (Δ = 11 Hz), and in individuals with a lower VHI score (increase of 0.7 Hz for each additional point). For females, post hoc comparisons revealed a substantial impact of teaching level on f_o: university instructors had deeper voices than kindergarten (Δ = 66 Hz), elementary (Δ = 52 Hz), or secondary teachers (Δ = 41 Hz).

CONCLUSIONS

Since higher f_o increases the mechanical stress related to vocal fold vibration, the screening and prevention of phonotrauma should focus primarily on women, particularly those who teach at lower levels, and teachers with more self-rated voice problems. The lower f_o of teachers who engage in nonprofessional voice activities may suggest acute inflammation or muscle fatigue due to voice overload.

Differences in Weeklong Ambulatory Vocal Behavior Between Female Patients With Phonotraumatic Lesions and Matched Controls

Purpose Previous work using ambulatory voice recordings has shown no differences in average vocal behavior between patients with phonotraumatic vocal hyperfunction and matched controls. This study used larger groups to replicate these results and expanded the analysis to include distributional characteristics of ambulatory voice use and measures indicative of glottal closure. Method Subjects included 180 adult women: 90 diagnosed with vocal fold nodules or polyps and 90 age-, sex-, and occupation-matched controls with no history of voice disorders. Weeklong summary statistics (average, variability, skewness, kurtosis) of voice use were computed from neck-surface acceleration recorded using an ambulatory voice monitor. Voice measures included estimates of sound pressure level (SPL), fundamental frequency (f _o), cepstral peak prominence, and the difference between the first and second harmonic magnitudes (H1-H2). Results Statistical comparisons resulted in medium-large differences (Cohen's d ≥ 0.5) between groups for SPL skewness, f _o variability, and H1-H2 variability. Two logistic regressions (theory-based and stepwise) found SPL skewness and H1-H2 variability to classify patients and controls based on their weekly voice data, with an area under the receiver operating characteristic curve of 0.85 and 0.82 on training and test sets, respectively. Conclusion Compared to controls, the weekly voice use of patients with phonotraumatic vocal hyperfunction reflected higher SPL tendencies (negatively skewed SPL) with more abrupt glottal closure (reduced H1-H2 variability, especially toward higher values). Further work could examine posttreatment data (e.g., after surgery and/or therapy) to determine the extent to which these differences are associated with the etiology and pathophysiology of phonotraumatic vocal fold lesions.

A Preliminary Exploration of Vocal Usage in Prospective Professional Voice Users (PPVUs): Students of the Alimah Course

BACKGROUND

Students of the Alimah degree are Prospective Professional Voice Users whose career involves teaching, preaching, and conducting religious activities. For them, a cultured and efficient voice is an important prerequisite for a successful career. This study aimed to explore vocal usage and knowledge of voice care among students pursuing the Alimah course.

OBJECTIVES

To check the period prevalence of voice problems among the students during the Alimah course, understand communication, and voice usage in daily situations, understand their lifestyle, assess their knowledge about voice and voice care through a self-reporting questionnaire.

METHOD

The data were obtained from 150 undergraduate students pursuing the Alimah degree in and around Nagapattinam and Thanjavur districts of Tamil Nadu, India, through a self-reporting questionnaire.

RESULTS

The students pursuing the course were at a high risk for developing voice problems, with a period prevalence of 70%. Excessive vocal load, inappropriate diet, phonotraumatic behaviours and limited knowledge of voice care were found to be the threats to voice problems among the population.

CONCLUSION

This population with a high prevalence rate of voice problems should be studied further. The authors suggest including lessons on vocal enhancement methods and voice care in the course curriculum of the Alimah degree.

Impact of Classroom Determinants on Psychosocial Aspects of Voice Among School Teachers of Indore, India: A Preliminary Survey

Teaching voice is the professional voice; often different in quality from our day-to-day speaking voice, and is supposed to be subjected to vocal abuse, misuse and overuse. This paper aims towards highlighting  the various classroom determinants that may impact teacher's voice and how these impacts can affect the daily activities in terms of functional emotional and psychosocial aspects. To understand the same, a cross sectional prospective study was conducted across eight English medium institutions of Indore (a city in central India) region. The study was carried out in three phases: formulation of a questionnaire, data collection (through administration of the questionnaire and VHI among sixty school teachers) followed by data analysis, to determine whether any association exists between the various classroom determinants and voice impairment. Significant association was found between determinants like teaching experience; number of classes, duration of breaks, use of any alternate method of teaching and alternate use of any amplification device with physical, emotional and functional aspects of life. The findings holistically indicate that various factors within the classroom environment only has a significant bearing on the voice disturbances of a school teacher's life thus deteriorating their quality of life. Thus it is substantial to begin a training programme by speech language pathologists in order to heighten awareness among teachers. After all voice disturbances are a real and treatable condition and with the right amount of training can be avoided.

Vocal Dose in Older Adults with Presbyphonia: An Analytic, Cross-Sectional Study

PURPOSE

Older patients with age-related voice changes (presbyphonia) are considered vocal under-doers due to a reportedly low a amount and intensity of voice use (ie, low vocal dose). This low voice use may be consequential to negative effects of presbyphonia like throat discomfort, as well as anxiety and frustration from difficulty communicating. Causally speaking, vocal fold atrophy (presbylaryngis) may indicate inadequate intrinsic laryngeal muscle loading with low voice use, though research is lacking. As a first step, this study examined voice use objectively using vocal dosimetry in older adults with presbyphonia. We hypothesized participants, especially if retired, would exhibit low vocal doses, and lower than reported for other populations.

METHOD

This research used an analytic, cross-sectional design with subgroup analyses to determine feasibility of vocal dosimetry in older adults with presbyphonia. Thirteen older adults with presbyphonia (7 males) completed vocal dose monitoring using an ambulatory phonation monitor (APM). The APM measured vocal parameters over a day of monitoring, from which time, cycle, and distance doses were calculated. Data also were gathered on demographics, vocal handicap, and vocal effort.

RESULTS

Descriptively, the group showed a low mean time dose as compared to published vocal dose data from other populations. Females exhibited significantly higher mean values of time dose, cycle dose, and fundamental frequency than males. Time dose for males was negatively correlated with vocal effort. Subgroup analyses failed to detect an effect of age group, but found significantly a higher mean value for time dose in employed, compared to retired, participants.

CONCLUSIONS

Consistent with self-report, we found older adults with presbyphonia exhibit low time doses, which were in contrast to high vocal doses published on teachers, patients with dysphonia, and even office workers. We found differences in vocal dose as a function of sex and employment status. Though a limited sample, findings suggest patients with presbyphonia may demonstrate low vocal dose, which may be a useful target in treatment.

Characteristics and Responses of Human Vocal Fold Cells in a Vibrational Culture Model

OBJECTIVES/HYPOTHESIS

This study was conducted to provide a vibrational culture model to investigate the effects of mechanical environments on cellular functions, and elucidate physiological characteristics of two different types of cells in vocal folds under static and vibrational conditions.

STUDY DESIGN

In vitro study of human vocal fold fibroblasts (hVFFs) and human macula flava stellate cells (hMF-SCs).

METHODS

hVFFs and hMF-SCs were exposed to a 2-second-on/2-second-off, 205 Hz vibration regime for 4 hours by using a vibrational culture model. We compared cell morphology, cell viability, and gene expression in extracellular matrix-related components, growth factors, and differentiation markers under static and vibratory conditions.

RESULTS

hVFFs and hMF-SCs differed in their morphologies and gene expression levels under static condition. The applied vibration did not induce changes in morphology and viability of either cell type. However, gene expression levels changed in both cell types in response to vibration; in particular, hMF-SCs exhibited a more sensitive response to vibration than that shown by hVFFs.

CONCLUSIONS

The vibrational culture model developed in this study enabled us to investigate the effects of the applied vibration on two types of vocal fold resident cells. As a result, we could demonstrate that hVFFs and hMF-SCs exhibited distinctively different characteristics under vibrational conditions.

LEVEL OF EVIDENCE

NA. Laryngoscope, 128:E258-E264, 2018.

Intra-speaker and inter-speaker variability in speech sound pressure level across repeated readings

The intra- and inter-speaker variability of speech sound pressure level (SPL) has been investigated under repeatability conditions in this work. In a semi-anechoic chamber, speech from 17 individuals was recorded with a sound level meter, a headworn microphone, and a vocal monitoring device. The subjects were asked to read twice and in sequence two phonetically balanced passages. The speech variability has been investigated for mean, equivalent, and mode SPL from each reading and device. The intra-speaker variability has been evaluated by means of the average among individual standard deviations in the four readings and it reached the maximum of 2 dB for mode SPL. For the inter-speaker variability, the experimental standard deviation of individual averaged SPL parameters among the four repeated measures has been calculated, obtaining the highest value of 5.3 dB for mode SPL. Changes in SPL variability have been evaluated with different logging intervals for each device. The influence of speech material has been investigated by the Wilcoxon test on paired lists of descriptive statistics for SPL distribution and equivalent SPL in the repeated readings. The data reported in this study may be considered as a preliminary reference for the investigation of changes in speech SPL over subjects.

Recent Innovations in Voice Assessment Expected to Impact the Clinical Management of Voice Disorders

This article provides a summary of some recent innovations in voice assessment expected to have an impact in the next 5–10 years on how patients with voice disorders are clinically managed by speech-language pathologists. Specific innovations discussed are in the areas of laryngeal imaging, ambulatory voice monitoring, and “big data” analysis using machine learning to produce new metrics for vocal health. Also discussed is the potential for using voice analysis to detect and monitor other health conditions.

Accuracy of Self-Reported Estimates of Daily Voice Use in Adults With Normal and Disordered Voices

PURPOSE

Accurate estimation of daily patterns of vocal behavior is essential to understanding the role of voice use in voice disorders. Given that clinicians currently rely on patient self-report to assess daily vocal behaviors, this study sought to assess the accuracy with which adults with and without voice disorders can estimate their amount of daily voice use in terms of phonation time.

METHOD

Eighteen subjects (6 patients, 6 matched members of a control group without voice disorders, 6 low voice users) wore the accelerometer-based Ambulatory Phonation Monitor (APM; model 3200, KayPENTAX, Montvale, NJ) for at least 5 workdays. Subjects were instructed to provide hourly self-reports of time spent talking using a visual analog scale. Spearman correlation coefficients and errors between self-reported and APM-based estimates of phonation time revealed subject- and group-specific characteristics.

RESULTS

A majority of subjects exhibited a significant bias toward overestimating their phonation times, with an average absolute error of 113%. Correlation coefficients between self-reported and APM-based estimates of phonation time ranged from statistically nonsignificant to .91, reflecting large intersubject variability.

CONCLUSIONS

Subjects in all 3 groups were moderately accurate at estimating their hourly voice use, with a consistent bias toward overestimation. The results support the potential role that ambulatory monitoring could play in improving the clinical assessment of voice disorders.

Silence and Voicing Accumulations in Italian Primary School Teachers With and Without Voice Disorders

OBJECTIVES

The relationship between the silence and voicing accumulations of primary school teachers and the teachers' clinical status was examined to determine whether more voicing accumulations and fewer silence accumulations were measured for the vocally unhealthy subjects than for the healthy subjects, which would imply more vocal loading and fewer short-term recovery moments.

METHODS

Twenty-six Italian primary school teachers were allocated by clinicians to three groups: (1) with organic voice disorders, (2) with subjectively mild organic alteration or functional voice symptoms, and (3) normal voice quality and physiology. Continuous silence and voicing periods were measured with the APM3200 during the teachers' 4-hour workdays. The accumulations were grouped into seven time intervals, ranging from 0.03-0.9 to 3.16-10 seconds, according to Italian prosody. The effects of group on silence and voicing accumulations were evaluated.

RESULTS

Regarding silence accumulations, Group 1 accumulated higher values in intervals between 0.1 and 3.15 seconds than other groups, whereas Groups 2 and 3 did not differ from each other. Voicing accumulations between 0.17 and 3.15 seconds were higher for subjects with a structural disorder. A higher time dose was accumulated by these subjects (40.6%) than other subjects (Group 2, 31.9%; Group 3, 32.3%).

CONCLUSIONS

Although previous research has suggested that a rest period of a few seconds may produce some vocal fatigue recovery, these results indicate that periods shorter than 3.16 seconds may not have an observable effect on recovery. The results provide insight into how vocal fatigue and vocal recovery may relate to voice disorders in occupational voice users.

The Prevalence of Teachers' Vocal Symptoms in Municipal Network of Education in Campo Grande, Mato Grosso do Sul, Brazil

OBJECTIVE

This study aims to provide an epidemiological overview of the teacher's voice and to examine the prevalence of voice problems at Municipal Board Education in Campo Grande, Mato Grosso do Sul, Brazil.

METHODS

This is a cross-sectional, descriptive, and quantitative study. Of the 4957 teachers registered with Municipal Board Education (Semed)/2013, 394 participated in this research. All seven urban areas of Campo Grande (Prosa, Bandeira, Anhanduizinho, Lagoa, Segredo, Centro, and Imbirussu) were sampled. The Ferreira et al. protocol was adapted and used for data collection. The Likert scale was used as the measurement method.

RESULTS

There was a high prevalence of vocal symptoms. Teachers had multiple symptoms related to the use of voice at work and acknowledged that the symptoms had adverse effects on their professional performance.

CONCLUSION

The severity of voice problems that the teachers experienced in daily speech therapy services and in the Municipal Network of Education was found in a significant number of participants in this research.

Prevalência de sintomas vocais em professores na rede municipal de ensino em Campo Grande - MS

Resumo: OBJETIVO: delinear o panorama epidemiológico sobre a voz do professor na Rede Municipal de Ensino de Campo Grande/MS, verificando a prevalência de sintomas vocais autorreferidos nessa população. MÉTODOS: trata-se de um estudo epidemiológico, transversal, descritivo, quantitativo. Dentre os 4.957 professores cadastrados na Semed/2013, 394 participaram da pesquisa. Todas as sete regiões urbanas do município (Prosa, Bandeira, Anhanduizinho, Lagoa, Segredo, Centro, Imbirussu) foram amostradas. Para a coleta de dados utilizou-se o protocolo de Ferreira e cols., adaptado, utilizando-se como método de mensuração a escala Likert. RESULTADOS: constatou-se alta prevalência de sintomas vocais autorreferidos. Os professores apresentaram múltiplos sintomas relacionados ao uso da voz no trabalho e perceberam os efeitos adversos em seu desempenho profissional. CONCLUSÃO: a seriedade dos problemas de voz do professor, vivenciados diariamente nos serviços de atendimento fonoaudiológico e na Rede Municipal de Ensino foi revelada em números expressivos nessa pesquisa.

Comparison of Vocal Vibration-Dose Measures for Potential-Damage Risk Criteria

PURPOSE

Schoolteachers have become a benchmark population for the study of occupational voice use. A decade of vibration-dose studies on the teacher population allows a comparison to be made between specific dose measures for eventual assessment of damage risk.

METHOD

Vibration dosimetry is reformulated with the inclusion of collision stress. Two methods of estimating amplitude of vocal-fold vibration are compared to capture variations in vocal intensity. Energy loss from collision is added to the energy-dissipation dose. An equal-energy-dissipation criterion is defined and used on the teacher corpus as a potential-damage risk criterion.

RESULTS

Comparison of time-, cycle-, distance-, and energy-dose calculations for 57 teachers reveals a progression in information content in the ability to capture variations in duration, speaking pitch, and vocal intensity. The energy-dissipation dose carries the greatest promise in capturing excessive tissue stress and collision but also the greatest liability, due to uncertainty in parameters. Cycle dose is least correlated with the other doses.

CONCLUSION

As a first guide to damage risk in excessive voice use, the equal-energy-dissipation dose criterion can be used to structure trade-off relations between loudness, adduction, and duration of speech.

Average Ambulatory Measures of Sound Pressure Level, Fundamental Frequency, and Vocal Dose Do Not Differ Between Adult Females With Phonotraumatic Lesions and Matched Control Subjects

OBJECTIVES

Clinical management of phonotraumatic vocal fold lesions (nodules, polyps) is based largely on assumptions that abnormalities in habitual levels of sound pressure level (SPL), fundamental frequency (f0), and/or amount of voice use play a major role in lesion development and chronic persistence. This study used ambulatory voice monitoring to evaluate if significant differences in voice use exist between patients with phonotraumatic lesions and normal matched controls.

METHODS

Subjects were 70 adult females: 35 with vocal fold nodules or polyps and 35 age-, sex-, and occupation-matched normal individuals. Weeklong summary statistics of voice use were computed from anterior neck surface acceleration recorded using a smartphone-based ambulatory voice monitor.

RESULTS

Paired t tests and Kolmogorov-Smirnov tests resulted in no statistically significant differences between patients and matched controls regarding average measures of SPL, f0, vocal dose measures, and voicing/voice rest periods. Paired t tests comparing f0 variability between the groups resulted in statistically significant differences with moderate effect sizes.

CONCLUSIONS

Individuals with phonotraumatic lesions did not exhibit differences in average ambulatory measures of vocal behavior when compared with matched controls. More refined characterizations of underlying phonatory mechanisms and other potentially contributing causes are warranted to better understand risk factors associated with phonotraumatic lesions.

Vocal Hyperfunction in Parents of Children With Attention Deficit Hyperactivity Disorder

OBJECTIVE

The objective of this study was to evaluate the presence of habits and symptoms of vocal hyperfunction in the parents of children with attention deficit hyperactivity disorder (ADHD).

METHODS

Parents of 24 children with ADHD and 30 children of a control group completed a specific questionnaire to detect the hyperfunctional use of the voice (excessive talking, excessive loudness, talking too fast, and shouting), hoarseness, vocal fatigue, mental and physical fatigue, and the degree of parental concern for the vocal health of their child.

RESULTS

Parents of children with ADHD spoke more often, faster, and stronger than the parents of the control group; in addition, they also used a louder volume than they usually used when they spoke to their children. The parents manifested more vocal, mental, and physical fatigue than the parents of the control group. There was a significant correlation between the "concern" for the vocal health of their children with respect to vocal symptoms of the children, the habits of vocal hyperfunctioning, and the symptoms suffered by the parents.

CONCLUSIONS

These results suggest that the parents of children with ADHD change their vocal attitude when communicating with their children. Most likely, the increased concern of parents with ADHD children and their respective level of stress lead to hyperfunctional vocal usage. This subsequently leads to symptoms of vocal, physical, and mental fatigue at the end of the day.

Voice dosimetry and monitoring, with emphasis on professional voice diseases: Critical review and framework for future research

Professional voice has become an important issue in the field of occupational health. Similarly, voice diseases related to occupations gain interest in insurance medicine, particularly within the frame of specific insurance systems for occupational diseases. Technological developments have made possible dosimetry of voice loading in the work-place, as well as long-term monitoring of relevant voice parameters during professional activities. A critical review is given, with focus on the specificity of occupational voice use and on the point of view of insurance medicine. Remaining questions and suggestions for future research are proposed.

Comparison of vocal loading parameters in kindergarten and elementary school teachers

PURPOSE Although a global picture exists of teachers' voice demands in general, few studies have compared specific groups of teachers to determine whether some are more at risk than others. This study compared the vocal loadings of kindergarten and elementary school teachers; professional and nonprofessional vocal load were determined for both groups. METHOD Twelve kindergarten and 20 elementary school female teachers without voice problems were monitored during 1 workweek using the Ambulatory Phonation Monitor. Vocal loading parameters analyzed were F0, SPL, time dose, distance dose, and cycle dose. RESULTS Comparisons between the groups showed significantly higher cycle dose and distance dose for kindergarten teachers than for elementary school teachers, in both professional and nonprofessional environments. Professional and nonprofessional voice use comparisons showed significant differences for all parameters, indicating that vocal load was higher in the professional environment for both groups. CONCLUSIONS The higher vocal doses measured in kindergarten teachers suggest that particular attention should be paid to this specific group of teachers. Although nonprofessional vocal load is lower than professional vocal load, it is important to take both into account because of their cumulative effects.

Dynamic vibration cooperates with connective tissue growth factor to modulate stem cell behaviors

Vocal fold disorders affect 3-9% of the U.S. population. Tissue engineering offers an alternative strategy for vocal fold repair. Successful engineering of vocal fold tissues requires a strategic combination of therapeutic cells, biomimetic scaffolds, and physiologically relevant mechanical and biochemical factors. Specifically, we aim to create a vocal fold-like microenvironment to coax stem cells to adopt the phenotype of vocal fold fibroblasts (VFFs). Herein, high frequency vibratory stimulations and soluble connective tissue growth factor (CTGF) were sequentially introduced to mesenchymal stem cells (MSCs) cultured on a poly(ɛ-caprolactone) (PCL)-derived microfibrous scaffold for a total of 6 days. The initial 3-day vibratory culture resulted in an increased production of hyaluronic acids (HA), tenascin-C (TNC), decorin (DCN), and matrix metalloproteinase-1 (MMP1). The subsequent 3-day CTGF treatment further enhanced the cellular production of TNC and DCN, whereas CTGF treatment alone without the vibratory preconditioning significantly promoted the synthesis of collagen I (Col 1) and sulfated glycosaminoglycans (sGAGs). The highest level of MMP1, TNC, Col III, and DCN production was found for cells being exposed to the combined vibration and CTGF treatment. Noteworthy, the vibration and CTGF elicited a differential stimulatory effect on elastin (ELN), HA synthase 1 (HAS1), and fibroblast-specific protein-1 (FSP-1). The mitogenic activity of CTGF was only elicited in naïve cells without the vibratory preconditioning. The combined treatment had profound, but opposite effects on mitogen-activated protein kinase (MAPK) pathways, Erk1/2 and p38, and the Erk1/2 pathway was critical for the observed mechano-biochemical responses. Collectively, vibratory stresses and CTGF signals cooperatively coaxed MSCs toward a VFF-like phenotype and accelerated the synthesis and remodeling of vocal fold matrices.

Associations between voice ergonomic risk factors and acoustic features of the voice

The associations between voice ergonomic risk factors in 40 classrooms and the acoustic parameters of 40 schoolteachers' voices were investigated. The risk factors assessed were connected to participants' working practices, working postures, and the indoor air quality in their workplaces. The teachers recorded spontaneous speech and sustained /a/ before and after a working day. Fundamental frequency, sound pressure level, the slope of the spectrum, perturbation, and harmonic-to-noise ratio were analysed. The results showed that the more the voice ergonomic risk factors were involved, the louder the teachers' voices became. Working practices correlated most often with the acoustic parameters; associations were found especially before a working day. The results suggest that a risky voice ergonomic environment affects voice production.

Modulating the behaviors of mesenchymal stem cells via the combination of high-frequency vibratory stimulations and fibrous scaffolds

We are interested in the in vitro engineering of artificial vocal fold tissues via the strategic combination of multipotent mesenchymal stem cells (MSCs), physiologically relevant mechanical stimulations, and biomimetic artificial matrices. We have constructed a vocal fold bioreactor that is capable of imposing vibratory stimulations on the cultured cells at human phonation frequencies. Separately, fibrous poly (ɛ-caprolactone) (PCL) scaffolds emulating the ligamentous structure of the vocal fold were prepared by electrospinning, were incorporated in the vocal fold bioreactor, and were driven into a wave-like motion in an axisymmetrical fashion by the oscillating air. MSC-laden PCL scaffolds were subjected to vibrations at 200 Hz with a normal center displacement of ∼40 μm for a total of 7 days. A continuous (CT) or a 1 h-on-1 h-off (OF) regime with a total dynamic culture time of 12 h per day was applied. The dynamic loading did not cause any physiological trauma to the cells. Immunohistotochemical staining revealed the reinforcement of the actin filament and the enhancement of α5β1 integrin expression under selected dynamic culture conditions. Cellular expression of essential vocal fold extracellular matrix components, such as elastin, hyaluronic acid, and matrix metalloproteinase-1, was significantly elevated as compared with the static controls, and the OF regime is more conducive to matrix production than the CT vibration mode. Analyses of genes of typical fibroblast hallmarks (tenascin-C, collagen III, and procollagen I) as well as markers for MSC differentiation into nonfibroblastic lineages confirmed MSCs' adaptation of fibroblastic behaviors. Overall, the high-frequency vibratory stimulation, when combined with a synthetic fibrous scaffold, serves as a potent modulator of MSC functions. The novel bioreactor system presented here, as a versatile, yet well-controlled model, offers an in vitro platform for understanding vibration-induced mechanotransduction and for engineering of functional vocal fold tissues.

Surgical versus non-surgical interventions for vocal cord nodules

BACKGROUND

This is an update of a Cochrane review first published in The Cochrane Library in Issue 2, 2001 and previously updated in 2007 and 2009.Vocal cord nodules are bilateral, benign, callous-like growths of the mid-portion of the membranous vocal folds. They are of variable size and are characterised histologically by thickening of the epithelium with a variable degree of inflammation in the underlying superficial lamina propria. They characteristically produce hoarseness, discomfort and an unstable voice when speaking or singing.

OBJECTIVES

To assess the effectiveness of surgery versus non-surgical interventions for vocal cord nodules.

SEARCH METHODS

We searched the Cochrane Ear, Nose and Throat Disorders Group Trials Register; the Cochrane Central Register of Controlled Trials (CENTRAL); PubMed; EMBASE; CINAHL; Web of Science; BIOSIS Previews; Cambridge Scientific Abstracts; ISRCTN and additional sources for published and unpublished trials. The date of the most recent search was 9 April 2012.

SELECTION CRITERIA

Randomised and quasi-randomised trials comparing any surgical intervention for vocal cord nodules with non-surgical treatment or no treatment.

DATA COLLECTION AND ANALYSIS

No suitable trials were identified.

MAIN RESULTS

No studies fulfilled the inclusion criteria.

AUTHORS' CONCLUSIONS

There is a need for high-quality randomised controlled trials to evaluate the effectiveness of surgical and non-surgical treatment of vocal cord nodules.

Investigations into vocal doses and parameters pertaining to primary school teachers in classrooms

Investigations into vocal doses and parameters were carried out on 40 primary school teachers (36 females and 4 males) in six schools in Italy, divided into two groups of three, A and B, on the basis of the type of building and the mid-frequency reverberation time in the classrooms, which was 1.13 and 0.79 s, respectively. A total of 73 working-day samples were collected (66 for females and 7 for males), from which 54 traditional lessons were analyzed separately. The average value over the working days of the mean sound pressure level of the voiced speech at 1 m from the teacher's mouth was 62.1 dB for the females and 57.7 dB for the males, while the voicing time percentage was 25.9 and 25.1 %, respectively. Even though the vocal doses and parameters did not differ for the two school groups, the differences in the subjective scores were significant, with enhanced scores in group B. A 0.72 dB increase in speech level per 1 dB increase in background noise level, L(A90), was found during traditional lessons, as well as an increase in the mean value of the fundamental frequency with an increase in L(A90), at a rate of 1.0 Hz/dB.

Ambulatory Monitoring of Daily Voice Use

Many common voice disorders are chronic or recurring conditions likely to result from faulty and/or abusive patterns of vocal behavior. Such behaviorally based disorders can be difficult to assess accurately in the clinical setting and potentially could be much better characterized by long-term ambulatory monitoring of vocal function as individuals engage in their typical daily activities. Ambulatory monitoring also could provide new insight into the actual role of voice use in common disorders and missing quantitative data on what constitutes normal levels of daily voice use for different groups of individuals, activities, and occupations. This report describes the motivation, previous development efforts, current state-of-the-art technology, and future directions in ambulatory monitoring of voice use.

From Reactive Intervention to Proactive Prevention: The Evolution of Occupational Dysphonia

Voice clinicians long have been aware of the concept of professional voice users: individuals who work in professions that have a higher incidence and increased risk for voice disorders. This realization, coupled with the documented impact of work-related dysphonia on the economy, has resulted in a growing international interest in developing occupational health benchmarks for voice use, similar to other standards developed for work-related factors such as noise-induced hearing loss. In this article, we review current perspectives and examine some issues related to occupational vocal health.

Variations in intensity, fundamental frequency, and voicing for teachers in occupational versus nonoccupational settings

PURPOSE

In this study, the authors created a more concise picture of the vocal demands placed on teachers by comparing occupational voice use with nonoccupational voice use.

METHOD

The authors used National Center for Voice and Speech voice dosimetry databank to calculate voicing percentage per hour as well as average dB SPL and fundamental frequency (F(0)). Occupational voice use (9:00 a.m.-3:00 p.m., weekdays) and nonoccupational voice use (4:00 p.m.-10:00 p.m., weekends) were compared (57 teachers, 2 weeks each).

RESULTS

Five key findings were uncovered: (1) Similar to previous studies, occupational voicing percentage per hour is more than twice that of nonoccupational voicing; (2) teachers experienced a wide range of occupational voicing percentages per hour (30+/-11% per hr); (3) average occupational voice was about 1 dB SPL louder than the nonoccupational voice and remained constant throughout the day; (4) occupational voice exhibited an increased pitch and trended upward throughout the day; and (5) some apparent gender differences were shown.

CONCLUSIONS

Data regarding voicing percentages, F(0), and dB SPL provide critical insight into teachers' vocal health. Further, because nonoccupational voice use is added to an already overloaded voice, it may add key insights into recovery patterns and should be the focus of future studies.

Vibration stimulates vocal mucosa-like matrix expression by hydrogel-encapsulated fibroblasts

The composition and organization of the vocal fold extracellular matrix (ECM) provide the viscoelastic mechanical properties that are required to sustain high-frequency vibration during voice production. Although vocal injury and pathology are known to produce alterations in matrix physiology, the mechanisms responsible for the development and maintenance of vocal fold ECM are poorly understood. The objective of this study was to investigate the effect of physiologically relevant vibratory stimulation on ECM gene expression and synthesis by fibroblasts encapsulated within hyaluronic acid hydrogels that approximate the viscoelastic properties of vocal mucosa. Relative to static controls, samples exposed to vibration exhibited significant increases in mRNA expression levels of HA synthase 2, decorin, fibromodulin and MMP-1, while collagen and elastin expression were relatively unchanged. Expression levels exhibited a temporal response, with maximum increases observed after 3 and 5 days of vibratory stimulation and significant downregulation observed at 10 days. Quantitative assays of matrix accumulation confirmed significant increases in sulphated glycosaminoglycans and significant decreases in collagen after 5 and 10 days of vibratory culture, relative to static controls. Cellular remodelling and hydrogel viscosity were affected by vibratory stimulation and were influenced by varying the encapsulated cell density. These results indicate that vibration is a critical epigenetic factor regulating vocal fold ECM and suggest that rapid restoration of the phonatory microenvironment may provide a basis for reducing vocal scarring, restoring native matrix composition and improving vocal quality.

Measurement of vocal doses in speech: experimental procedure and signal processing

An experimental method for quantifying the amount of voicing over time is described in a tutorial manner. A new procedure for obtaining calibrated sound pressure levels (SPL) of speech from a head-mounted microphone is offered. An algorithm for voicing detection (kv) and fundamental frequency (F0) extraction from an electroglottographic signal is described. The extracted values of SPL, F0, and kv are used to derive five vocal doses: the time dose (total voicing time), the cycle dose (total number of vocal fold oscillatory cycles), the distance dose (total distance travelled by the vocal folds in an oscillatory path), the energy dissipation dose (total amount of heat energy dissipated in the vocal folds) and the radiated energy dose (total acoustic energy radiated from the mouth). The doses measure the vocal load and can be used for studying the effects of vocal fold tissue exposure to vibration.

The effects of a sound-field amplification system on managerial time in middle school physical education settings

PURPOSE

The focus of this research effort was to examine the effect of a sound-field amplification system on managerial time in the beginning of class in a physical education setting.

METHOD

A multiple baseline design across participants was used to measure change in the managerial time of 2 middle school female physical education teachers using a portable sound-field amplification system. Managerial time is defined as the cumulative amount of time that students spend on organizational, transitional, and nonsubject matter tasks in a lesson.

RESULTS

The findings showed that the amount of managerial time at the beginning of class clearly decreased when the teacher used sound-field amplification feedback to physical education students.

CONCLUSION

Findings indicate an immediate need for administrators to determine the most appropriate, cost-effective procedure to support sound-field amplification systems in existing physical education settings.

The effect of bioreactor induced vibrational stimulation on extracellular matrix production from human derived fibroblasts

To study the affect of mechanical stimuli on human laryngeal fibroblasts, we developed bioreactors capable of vibrating cell seeded substrates at frequencies and displacements comparable to measured phonation values in human subjects. In addition, we developed a means of harvesting the secreted matrix as a bulk biomaterial by removing the polymer foam using an organic solvent. Using the system human derived laryngeal fibroblasts were subjected to vibrational stimuli (100 Hz) for 1-21 days. Following mechanical conditioning, extracellular matrix and matrix related gene expression, cytokine production, matrix protein accumulation, and construct material properties were assessed with DNA microarray, enzyme linked immunosorbent, indirect immunofluorescent, and uni-axial tensile assays respectively. The results show that vocal fold-like vibrational stimuli is sufficient to influence the expression of several key matrix and matrix related genes, enhance the secretion of the profibrotic cytokine TGFbeta1, increase the accumulation of the extracellular matrix proteins, fibronectin and collagen type 1, as well as enhance construct stiffness compared to non-stimulated controls. Our results demonstrate that high frequency substrate vibration, like cyclic strain, can accelerate matrix deposition from human derived laryngeal fibroblasts. The study supports the notion that preconditioning regimens using human cells may be useful for producing cell derived biomaterials for therapeutic application.

Changes in Objective Acoustic Measurements and Subjective Voice Complaints in Call Center Customer-Service Advisors During One Working Day

SUMMARY

The aim of this study was to investigate how different acoustic parameters, extracted both from speech pressure waveforms and glottal flows, can be used in measuring vocal loading in modern working environments and how these parameters reflect the possible changes in the vocal function during a working day. In addition, correlations between objective acoustic parameters and subjective voice symptoms were addressed. The subjects were 24 female and 8 male customer-service advisors, who mainly use telephone during their working hours. Speech samples were recorded from continuous speech four times during a working day and voice symptom questionnaires were completed simultaneously. Among the various objective parameters, only F0 resulted in a statistically significant increase for both genders. No correlations between the changes in objective and subjective parameters appeared. However, the results encourage researchers within the field of occupational voice use to apply versatile measurement techniques in studying occupational voice loading.

Vocal fatigue and its relation to vocal hyperfunction †

This article reviews current literature on vocal fatigue and considers its potential relationship to vocal hyperfunction. Vocal fatigue is defined by its symptoms. Specifically, the voice user perceives an increase in phonatory effort over time that may be accompanied by decreased phonatory function. Vocal fatigue can present as a pure condition, such that no specific aetiology is apparent, or as a component of other voice disorders. The underlying bases of vocal fatigue appear to include the neurophysiological and biomechanical effects of extended periods of phonation. It can also be a function of strategies used to adapt to extended periods of phonation, such as the use of excessive muscular tension and suboptimal vocal fold posturing. Studies that have attempted to identify observable responses that are reliably associated with vocal fatigue have met with limited success, but recent advances in research methodology are promising. This review addresses current approaches to the study of vocal fatigue, especially regarding subject selection, design variables, and measurement variables. Future studies should address the relationship between vocal fatigue and other voice disorders, differences in individual responses to vocal-loading tasks, and differential evaluation and management of the neuromuscular, biomechanical, and central processes involved in vocal fatigue.

The Voice Handicap of Student-Teachers and Risk Factors Perceived to Have a Negative Influence on the Voice

A cross-sectional questionnaire survey was performed. The objectives of the study were to assess the psychosocial impact of current voice complaints as perceived by student-teachers with voice complaints in comparison with student-teachers without voice complaints, and to observe the pattern of risk factors in relation to their voice handicap. Subjects in the general population without a voice-demanding profession were selected as a reference group for limited comparison with the total group of student-teachers (future professional voice users). The respondents to the questionnaires were anonymous. Among the student-teachers, 17.2% reported current voice complaints in comparison with 9.7% of the reference group, and the odds ratio was 1.94, which showed the relative risk. Student-teachers had significantly greater total Voice Handicap Index (VHI) scores than the reference group (P = 0.034). The VHI subscale scores were not significantly different (P > 0.05). Student-teachers who reported current voice complaints had a significantly higher total VHI and subscale scores than student teachers without voice complaints (P < 0.001). Of the student-teachers without voice complaints, 17.0% had VHI scores greater than the 75th percentile. These persons may be neglecting their voice handicap and probably represent the false-negative cases in the estimation of voice complaints. Logistic regression analysis of each of the given risk factors with the VHI as the independent variable showed that the perceived negative influence of the given risk factors on their voices was significantly greater with increasing VHI scores across the VHI range. A significant correlation was observed between the number of perceived risk factors and increasing VHI scores across the VHI range. An increased awareness of risk factors in relation to their voice handicap would serve to motivate student-teachers to change factors that contributed to their voice problem. Attention to all risk factors, which the subjects perceive to be a risk, would aid in effective management of their voice handicap.