Vocal Demand Response to the Educational Setting Based Communication Scenarios: A Single Subject Study

Objectives: This was a single-subject study, aimed to demonstrate different vocal demand situations that are typical for primary school and teacher's vocal demand response under two acoustical conditions, with and without voice amplification, during five working days. Methods: The long-term voice dosimetry with Vocal Holter Med (PR.O. Voice Srl) was carried out on a 49-year-old female teacher with voice disorders during daily teaching activities. A sound field amplification system (SFAS) PentaClass Runa was installed in the classroom. Voice dosimetry was provided under two different acoustical conditions: without SFAS (2 days) and with SFAS (3 days). Results: Phonation time percentage, sound pressure level (SPL), SPL SD, fundamental frequency (F0), F0 SD, cycle, and distance doses were investigated in seven communication scenarios (lessons, group/individual classes, sports lessons in the gym and schoolyard, breaks, lunch breaks, and other activities). The median scores of all voice parameters differed significantly between different vocal demand contexts. The significant statistical difference in the vocal demand response was in the communication situations with and without SFAS. In addition, the number of children, reverberation time, and ambient air relative humidity impacted voice SPL and the cycle dose. Conclusions: Lessons, sports lessons held in the gym or schoolyard, breaks, and lunch breaks were considered as high vocal demand communication situations requiring higher voice intensity and fundamental frequency, higher phonation time percentage, cycle, and distance doses. Group/individual work and other teacher activities during the day, unrelated to direct work with students, were categorized as low vocal demand communication scenarios.

Objetivos: Este fue un estudio de sujeto único, cuyo objetivo fue demostrar diferentes situaciones de demanda vocal típicas de la escuela primaria y la respuesta vocal de los docentes bajo dos condiciones acústicas, con y sin amplificación de voz, durante cinco días laborables. Métodos: Se llevó a cabo dosimetría vocal a largo plazo con Vocal Holter Med (PR.O. Voice Srl) durante las actividades diarias de enseñanza en una docente de 49 años con trastornos de la voz. Se instaló un sistema de amplificación de campo sonoro (SFAS) PentaClass Runa en el aula. La dosimetría vocal se realizó bajo dos condiciones acústicas diferentes: sin SFAS (2 días) y con SFAS (3 días). Resultados: Se investigaron el porcentaje de tiempo de fonación, el nivel de presión sonora (SPL), SPL SD, la frecuencia fundamental (F0), F0 SD, ciclos y dosis de distancia en siete escenarios de comunicación diferentes (clases, clases grupales/individuales, clases de educación física en el gimnasio y el patio de la escuela, recreos, almuerzos y otras actividades). Las puntuaciones medias de todos los parámetros vocales diferían significativamente entre los diferentes contextos de demanda vocal. La diferencia estadísticamente significativa en la respuesta a la demanda vocal se observó en las situaciones de comunicación con y sin SFAS. Además, el número de niños, el tiempo de reverberación y la humedad relativa del aire ambiente afectaron al SPL de la voz y la dosis de ciclo. Conclusiones: Las lecciones, las clases de educación física en el gimnasio o el patio de la escuela, los recreos y los almuerzos se consideraron situaciones de comunicación de alta demanda vocal, que requerían una mayor intensidad y frecuencia fundamental de la voz, un mayor porcentaje de tiempo de fonación y dosis de ciclo y distancia más altas. El trabajo grupal/individual y otras actividades del profesor durante el día no relacionadas con el trabajo directo con los estudiantes se categorizaron como escenarios de comunicación de baja demanda vocal.

The effect of sound field amplification systems on vocal demand response in teachers during lessons.

PURPOSE: Sound pressure level (SPL), fundamental frequency (F0), time dose (Dt), cycle dose (Dc), and distance dose (Dd) are components affecting a vocal demand response. The study aimed to investigate the impact of sound field amplification systems (SFAS) on teachers' vocal parameters and determine the user comfort of SFAS use in teachers. METHODS: Twenty female teachers underwent long-term voice dosimetry with Vocal Holter Med (PR.O.Voice Srl) during everyday teaching activities. The SFAS PentaClassRuna (Certes) was installed in classrooms. Voice dosimetry was provided in two different acoustical conditions-without the use of SFAS (one to two days) and with SFAS (one to three days). Teachers underwent voice acoustic and laryngoscopic evaluation before voice dosimetry. Two teachers' groups were formed: teachers with and without vocal nodules. The visual analogue scale measured the user comfort of SFAS. RESULTS: There were no significant differences in vocal parameters and vocal doses between teachers with and without vocal nodules. Voice amplification significantly decreased average F0(-4.4 Hz), Dt%(-3.1%), Dc (-0.4 kcycles), and Dd (-1.3 m) in teachers without vocal nodules and F0 (-8.9 Hz) in teachers with vocal nodules. Vocal doses (Dt%, Dc, Dd) significantly decreased in classrooms with longer reverberation time. The user comfort of the SFAS during the lessons was high in both teachers groups. CONCLUSIONS: SFAS was a mediator between the classroom's environment and the teacher's vocal demand response; it changed teachers' voice production parameters and reduced vocal demand response to satisfy the communication requirements. In addition, voice amplification was more beneficial for teachers without vocal fold lesions.

A User-Centered Design Approach to Developing a Voice Monitoring System for Disorder Prevention.

BACKGROUND: Many individuals will experience a voice disorder in their lifetime, especially occupational voice users. While a number of voice monitoring systems have been developed, most were designed with the clinician/researcher as the end user. For a patient to use these systems, they need field experts to help them interpret data from the system to understand its meaning. Most of these systems would have challenges in being used in a preventative context with the occupational voice user as the sole system user. OBJECTIVE: The current study introduces a novel design approach: user-centered design (UCD) with paper prototypes in the creation of a voice monitoring system for voice disorder prevention (VDP). The goal of this design approach is to design systems that are engaging and intuitive for users so they will be interested in interacting with the system and be able to benefit from the system without the need of external support. METHODS: The current study was conducted in two phases: an iterative design phase and a test phase. In the iterative design phase, 15 participants gave their opinions on the measures and feedback designs they felt would be the most beneficial to users. In the test phase, the researchers collected real voice data over multiple sessions for 18 additional participants and provided this data using the final feedback displays from the design phase. RESULTS: By engaging in UCD, the researchers identified key design challenges for VDP: (1) educating the user, (2) balancing contextualization and granularity, and (3) addressing disconnection between user and system goals. CONCLUSION: UCD holds promise for designing VDP systems that are both engaging and intuitive for occupational voice users.

Work-Related Communicative Profile of Voice Teachers: Effects of Classroom Noise on Voice and Hearing Abilities.

PURPOSE: Vocal instructors during their normal workday are exposed to high noise levels that can affect their voice and hearing health. The goal of this study was to evaluate the voice and hearing status of voice instructors before and after lessons and relate these evaluations with voice and noise dosimetry taken during lessons. METHODS: Eight voice instructors volunteered to participate in the study. The protocol included (1) questionnaires, (2) pre/post assessment of voice quality and hearing status, and (3) voice and noise dosimetry during lessons. Acoustic measurements were taken of the unoccupied classrooms. RESULTS: In six of eight classrooms, the measured noise level was higher than the safety recommendations set by National Institute for Occupational Safety and Health. The background noise level and the reverberation time in the classrooms were in compliance with the national standard recommendations. We did not find a clear pattern comparing pre- and post-measurements of voice quality consistent among genders. In all subjects, the Sound Pressure Levels mean increased, and the standard deviation of fundamental frequency decreased indicating association to vocal fatigue. Previous studies link these changes to increasing vocal fatigue. The audiometric results revealed seven out of eight instructors have sensorineural hearing loss. CONCLUSIONS: The interaction of the acoustic space and noise levels can contribute to the development of hearing and voice disorders for voice instructors. If supported by larger sample size, the results of this pilot study could justify the need for a hearing and voice conservation program for music faculty.

Gender differences in vocal doses among occupational voice users: a systematic review of literature and meta-analysis.

BACKGROUND: Occupational voice users such as teachers, singers, and broadcasters have high vocal demands increasing the risk for developing voice disorders. Among occupational voice users, the literature has report gender differences in vocal doses as part of vocal demands. However, these differences have not been quantified. OBJECTIVE: To determine differences per gender on vocal doses among different groups of occupational voice users. METHODS: A systematic review of literature and meta-analysis were conducted on publications about vocal dose among occupational voice users. In total, 242 potential articles were found. After screening of titles and abstracts, 16 papers were included for full revision in the systematic review of literature. For the meta-analysis, 7 out of 16 papers were included. RESULTS: Females had higher phonation time percentage compared with males (mean difference = 1.44, p value = .16). Nevertheless, this difference was not statistically significant. Among call centre operators, there was no difference in time doses associated with gender. Sport teachers had high values in time dose percentage, dissipation, and radiated energies. CONCLUSIONS: The meta-analysis shows variations in time doses, which could be associated with the vocal demand responses for females compared with males in occupational voice settings. Future investigations are required for establishing safe limits criteria for vocal doses, as well as vocal functioning in different working context.

Quantifying Vocal Repertoire Tessituras Through Real-Time Measures.

INTRODUCTION: Voice teachers use anecdotal evidence and experience in determining the appropriateness of repertoire for each student's development. Tessitura is important in that determination, but until recently a straightforward, repeatable, and quantifiable method for determining tessitura has not existed. However, technology exists to provide the means to estimate the tessituras of standard vocal repertoire by measuring sung pitch (fundamental frequency) and vocal dose (amount of phonation) in real-time performance. PURPOSE: The purpose of this study was to examine the combined use of tessituragrams, Voice Range Profiles (VRPs), a singer's self-perception of a performance, and expert listeners perception of a performance towards the goal of a more systematic way of selecting appropriate voice repertoire for singers. The following research questions guided this investigation: 1) How do Performance Range Profiles (PRPs, performance-based tessituragrams computed from neck skin surface vibration during singing), compare to score-based tessituragrams of the same selection in the same key? 2) How do PRPs of the same vocal score compare when performed in three different keys? 3) How do singer VRPs compare with PRPs of three performances of a score, each sung in a different key? and 4) How do singer and expert panel perceptions of the selection's "fit" in three different keys compare with the alignment of each singer's VRP to their PRPs? Four female singers and five expert voice pedagogues were enlisted to address these questions. RESULTS: The distribution (histogram) of the score-based tessituragram closely matched the distribution of performance-based tessituragrams (PRP), suggesting that score-based tessituragrams have promise in accurately reflecting the performance-based tessitura of a musical vocal work. Acquired data revealed relationships of practical importance between score-derived tessituragrams, PRPs, acquired VRPs, and singer perceptions of ease in singing. These data suggest that score-based tessituragrams aligned with singer VRPs show promise in repertoire selection. However, there was only a minor relationship between expert panel perceptions of ease in singing and the acquired PRPs or singer perceptions of ease. Creation of a score-based tessituragram database could be combined with singer VRPs to assist in appropriate repertoire selection.

The Effects of Amplification on Vocal Dose in Teachers with Dysphonia.

PURPOSE: The purpose of this study was to determine if voice amplification influenced vocal dose in female teachers with dysphonia. MATERIAL AND METHODS: This was an experimental study with comparative intrasubjects in which 15 individuals were compared in two different moments: condition 1 (C1) without voice amplification and condition 2 (C2) with voice amplification. All of them were female, kindergarten and elementary school teachers who presented organic or functional dysphonia. The search was carried out at the school where the teachers work. The professional voice use was considered the teachers' activity for a continuous period of two classes (average recording time of 96 minutes, with no difference in time between C1 and C2). To measure the dose we used the vocal dosimeter composed of a microphone, an accelerometer fixed to the neck, and a portable unit that stores the vocal data. The phonation data (intensity, fundamental frequency, phonation percentage, cycle dose, and distance dose) were analyzed by the equipment software (VoxLog). RESULTS: The use of vocal amplification in teachers promotes a reduction of the fundamental frequency (295.6-267.7 Hz), the voice intensity (96.2-93.3 dB sound pressure level), the cycle doses (489.4-345.2 thousand cycles per second), and distance doses (3,800-2,300 m). CONCLUSION: The vocal amplification allows the teacher to maintain the same phonation time (phonation percentage) but decreases the number of vocal fold oscillations (cycle dose) and the total distance traveled by the vocal fold tissue during phonation (distance dose), reducing the exposure of the vocal folds to voice trauma.

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.

Ambulatory phonation monitoring in a sample of 92 call center operators.

OBJECTIVES: The voice is a primary work tool for call center operators, but the main risk factors for voice disorders in this category have not yet been clarified. This study aimed to analyze the vocal behavior in call center operators and search for correlations between the daily voice dose and the self-perceived voice-related handicap. STUDY DESIGN: Prospective. SUBJECTS AND METHODS: Ninety-two call center operators (aged 24-50 years) underwent ambulatory phonation monitoring during a working day and were administered the Voice Handicap Index (VHI) questionnaire and a questionnaire concerning smoking habits, symptoms, and extrawork activities requiring intensive voice use. RESULTS: Mean percentage phonation time (PT) during work was 14.74% and ranged from 4% to 31%. There was a significant difference between the percentage PT in working time and in extrawork time; however, subjects with high percentage PT in working time maintained a high value also in extrawork time. The mean PT was 87.5 ± 35.8 minutes and was not correlated with age, gender, number of work hours, symptoms, extraprofessional voice use, and VHI scores. The mean amplitude was significantly higher in subjects with longer PT and higher pitch (P < 0.001). VHI score (median = 9) was slightly higher than in the general population but not related to the number of work hours, indicating that work time was not a critical factor in causing the perception of voice problems. CONCLUSION: Our study provides data about the voice behavior of a large cohort of call center operators and demonstrates that the number of work hours and the percentage PT are not statistically related to the perception of voice disturbances in this working category.