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.

Choral Conductors Vocal Loading in Rehearsal Simulation Conditions.

OBJECTIVES: Choir conductors represent a profession with an intensive vocal load. The present study aims to investigate the impact of 40 minutes vocal loading tasks on fundamental frequency (F0), jitter (Jitt), shimmer (Shim), median cepstral peak prominence (CPPs), and CPPs standard deviation in specific acoustic conditions. METHOD: Eighteen amateur choir conductors (13 female, five male) participated in the study. The vocal loading experiment was organized in rooms where each conductor usually had choir rehearsals. The vocal loading experiment included vocal warm-up, singing, and loud reading. The STIPA test signal provided the background noise with 60 dBA @ 1m during the singing and reading tasks. The F0, Jitt, Shim, CPPs, and CPPs SD were extracted before and after vocal loading by the Vocal Holter Med (VHM) device. Additionally, Acoustic Voice Quality Index (AVQI) was estimated for participants, and all of them completed the Voice Handicap Index-30 (VHI-30) and the Singing Voice Handicap Index (SVHI). Finally, reverberation time (T30) was measured in each rehearsal room. RESULTS: A statistically significant decrease of CPPs SD by 0.1 dB was observed in male conductors. Associations between CPPs SD and VHI-30 (r = 0.789, P = 0.001) were found in female conductors, and between Jitt and SVHI (r = 0.9, P = 0.037) in male conductors. Female conductors with higher total score of SVHI demonstrated increase of postloading F0 (r = 0.612, P = 0.026). CONCLUSIONS: Forty-minute vocal loading tasks that included warm-up, intensive singing, and loud reading did not significantly impact vocal parameters in female and male conductors. In addition, the rehearsal room volume and length of reverberation time did not affect obtained vocal parameters after vocal loading.

Investigating voice differences in teachers with and without self-reported voice disorders, and healthcare workers without self-reported voice disorders.

OBJECTIVE: The present study had two objectives: (1) to investigate differences in voice parameters between teachers with and without self-reported voice disorders and (2) to find differences in voice parameters between teachers and healthcare workers without self-reported voice disorders. METHOD: Three respondents' groups were formed: teachers with self-reported voice disorders (mean age, 47 years; range, 34-60 years), teachers without self-reported voice disorders (46; 27-64), and healthcare workers without self-reported voice disorders (45; 31-63). All participants were women. Maximum Phonation Time (MPT), fundamental frequency (F0), jitter, shimmer, frequency and intensity range, Dysphonia Severity Index (DSI), Voice Handicap Index-30 (VHI), and perceived stress (PSS) were assessed in respondents. RESULTS: Twenty-nine percent of teachers noted two or more vocal symptoms daily or weekly. Teachers with self-reported voice disorders had a higher degree of perceived stress (18 vs. 13, p = .009), higher score on the VHI (25 vs. 13, p = .001), and lower score on the DSI (2.65 vs. 3.21, p = .037), than teachers without self-reported voice disorders. The VHI-30 score of 15 points could be a cut off value describing voice disorders in female teachers. Differences between teachers and health care workers without self-reported voice disorders were found in MPT (p = .001), F0 (p = .012), jitter (p = .009), DSI (p = .023), and the perceived stress score (p = .041). CONCLUSIONS: The teaching profession can influence the voice, and the presence of psycho-emotional factors can lead to the development of voice disorders in teachers.

Epidemiology of Voice Disorders in Latvian School Teachers.

OBJECTIVES: The prevalence of voice disorders in the teacher population in Latvia has not been studied so far and this is the first epidemiological study whose goal is to investigate the prevalence of voice disorders and their risk factors in this professional group. METHODS: A wide cross-sectional study using stratified sampling methodology was implemented in the general education schools of Latvia. The self-administered voice risk factor questionnaire and the Voice Handicap Index were completed by 522 teachers. Two teachers groups were formed: the voice disorders group which included 235 teachers with actual voice problems or problems during the last 9 months; and the control group which included 174 teachers without voice disorders. RESULTS: Sixty-six percent of teachers gave a positive answer to the following question: Have you ever had problems with your voice? Voice problems are more often found in female than male teachers (68.2% vs 48.8%). Music teachers suffer from voice disorders more often than teachers of other subjects. Eighty-two percent of teachers first faced voice problems in their professional carrier. The odds of voice disorders increase if the following risk factors exist: extra vocal load, shouting, throat clearing, neglecting of personal health, background noise, chronic illnesses of the upper respiratory tract, allergy, job dissatisfaction, and regular stress in the working place. CONCLUSIONS: The study findings indicated a high risk of voice disorders among Latvian teachers. The study confirmed data concerning the multifactorial etiology of voice disorders.

Adaptation and validation of the Voice Handicap Index in Latvian.

OBJECTIVES: To establish psychometric indicators of the Voice Handicap Index (VHI) (Latvian version) and their relationship to the psychometric indicators of the original items. STUDY DESIGN: Parallel group design. METHODS: The VHI was translated and adapted to Latvian. The translated version of the VHI (Lat-VHI) was completed by 54 patients with voice disorders and by 73 subjects without voice disorders forming the control group. A test-retest group included 54 subjects without voice problems, able to complete the questionnaire twice. The test-retest stability, internal consistency of items of the Lat-VHI, and content and convergent validity of the Latvian version of the VHI were analyzed. RESULTS: The interclass correlation coefficient ratio of all scales indicated statistically significant (P<0.001) test-retest reliability for the Lat-VHI. High internal consistency was observed among the Lat-VHI total scale (α=.96), functional (α=.92), physical (α=.86), and emotional scale (α=.91) in the patient group. The Pearson moment correlation coefficient indicates a high correlation among the Lat-VHI total scale and subscales (r>0.94), as well as a high correlation among subscales (r>0.81) in the patient group. Convergent validity of the Lat-VHI was determined by comparing the Lat-VHI results with the Voice Disorder Severity scale results. Statistically significant correlation (r=0.78, P<0.001) was discovered in the patient group. CONCLUSIONS: The Latvian version of the VHI is a psychometrically validated instrument whose indicators correspond to the psychometric indicators of the original sample.