General information

This is an Open Access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

*Corresponding author:

Centro de Ciências da Saúde, Núcleo de Propedêutica e Terapêutica (NUPROP) da Universidade Estadual de Ciências da Saúde de Alagoas (Uncisal)

Addr.: Rua Jorge de Lima, 113. Bairro: Trapiche da Barra. Maceió, AL, Brasil | CEP 57010- 382

Phone: +55 82 9.8853.4569

This study was carried out at Universidade Estadual de Ciências da Saúde de Alagoas (Uncisal)

Introduction

Teaching has been considered one of the activities that most generate vocal problems, showing the need for care regarding these professionals' vocal health. Teachers have a higher prevalence of vocal disorders than non-teachers (11.6% versus 7.5%, respectively)1. In a study conducted with 317 elementary and high school teachers, about 81% of the participants had dysphonia2.

Considered an essential resource in the dialogical teacher-student relationship, the voice, when altered, can have direct consequences on communication in the classroom3, 4, 5. Preventive measures, such as actions to promote vocal health and well-being, are essential to promote changes in teachers' vocal behavior and attenuate damage to vocal health, thus favoring clarity, longevity, and better performance of his voice in the classroom, curbing absence from work activities6, 7, 8, 9.

The results of actions to promote educators' vocal health, after theoretical-practical training9, point to reducing undesirable vocal symptoms, providing better perceptual awareness of voice quality and, due to this bias, changes in vocal behavior by learning the techniques acquired in their daily activities⁴. Such results highlight the importance of programs involving teachers' vocal education, although there is a need for more improved knowledge of strategic actions and their undoubted effectiveness, aiming at the polished excellence of programs/actions for teachers from kindergarten to high school10.

Other studies11, 12 compared the effect of direct and indirect vocal therapy on the voice. The current study expands the discussion by describing the results of these interventions used in programs/actions to promote the teacher's vocal health who works in early childhood, elementary and high school. Understanding and analyzing the effects of these interventions and how their results are measured allows for a better selection of strategies by speech therapists with evidence of their effectiveness. Thus, social relevance is highlighted with a return to the target population, minimizing the vocal suffering of these professionals, who have their voices as a work tool, allowing them to perform their work activity with a maximum vocal efficiency.

Given the above, this study aimed to identify the speech therapy strategies used to promote vocal health to teachers of early childhood, elementary and high school participating in programs/actions for prevention and promotion of vocal health and to describe and analyze their effects, through an integrative literature review.

Methods

The following guiding question was raised to conduct the study: what are the speech therapy strategies used to promote vocal health in early kindergarten, elementary, and high school teachers and their effectiveness within the teachers' vocal health programs/actions?

Searches were performed in the electronic databases Lilacs (via BVS), SciELO, and Medline (via PubMed) in addition to manual search within the references of the pre-selected articles themselves. The controlled descriptors (DeCS) used were“disfonia”, “distúrbios da fonação”, “docentes”, “educador”, “professor”, “fonoterapia”, “treinamento da voz”, in Portuguese and their English counterparts (MeSH): “dysphonia”, “voice disease”, “school teachers”, “vocal training” and “speech therapy”. The Boolean operators AND and OR were used to cross the descriptors as in the model with MeSH for Medline via PubMed: (((("Dysphonia"[Mesh]) OR ("Voice Disorders"[Mesh])) AND ("School Teachers"[Mesh))) AND ("Speech Therapy"[Mesh]) OR ("Voice Training"[Mesh])))).

The literature review occurred between November 2018 and April 2019, with the search updated in August 2019. From the electronic search, 624 available articles were included in this study. At the end of the research process of screening and selection, six articles were selected.

Inclusion criteria consisted of complete articles available online in any language and year of publication, which presented strategies for promoting vocal health and preventing disorders in the target population employed in vocal health programs/actions with elementary school teachers and high school. Abstracts of scientific events, case reports, and experiences, narrative review studies, systematic and integrative were excluded; theses and dissertations, in addition to those that presented strategies for collective work, but unrelated to programs or actions to promote the teachers' vocal health.

The studies' selection was performed by two authors, who independently read all the titles and abstracts of the identified studies through electronic search. Disagreeing cases were analyzed by a third reviewer who issued a final opinion. The selected articles were read in full by two authors, who also extracted the data independently, using a data extraction form prepared for this integrative review. Disagreement cases were once again discussed with a third reviewer who arbitrated on the case.

A summary table was constructed with the selected studies to present the results considering the following aspects: the type of study, place/country where it was developed, aim, strategies used in the intervention, the form of evaluation of the intervention results, the main results, and conclusion. The studies were presented in chronological order of publication. A critical analysis was sought at this stage, explaining the conflicting factors between the different studies. The synthesis of the studies was assessed descriptively.

Results

The electronic search resulted in 624 publications. After excluding duplicates, 615 studies remained, of which 15 were read in full, resulting in six studies included. The description of the results regarding article retrieval, selection, and inclusion of studies, is detailed in a flow diagram13 format, corresponding to Figure 1

Table 1 presents the main characteristics of the included studies and the description of the interventions, evaluation of the outcomes, and conclusions of the authors. The six included studies totaled 189 teachers. The participants' mean age ranged from 31.5 ± 3.1 years to 39.4 ± 9 years. One study¹⁴ presented the age group between 25 and 52 years, not providing data on the average age. The profession time was informed by only three studies, comprising an average of approximately 12 years among the subjects who underwent intervention. The weekly workload was not described in half of the studies; in the other half, the average was 5.5 to 28.6 hours per week.

Four studies were conducted in Brazil14, 15, 16, 17, one in China18 and another in the United States19. Among the studies conducted in Brazil, most were developed in the southeast of the country. According to the types of studies conducted, only the non-Brazilian were randomized clinical trials. As for the level of education, five studies were not explicit in identifying the sample, so it was impossible to specify the number of teachers that comprised the sample by levels – kindergarten, elementary and high school – or part of them. It is worth considering that the number of studies included is low.

Discussion

All studies were conducted in municipal or state schools, and the teachers' vocal health programs presented theoretical and practical content. Among the objectives presented by the included studies, some sought to show the effectiveness of practices related to vocal health programs; others sought, beyond effectiveness, to analyze the professionals' adherence to the programs and satisfaction of participating in the entire circle.

The programs and actions aimed at the teacher's vocal well-being present theoretical and practical content as an intervention approach; mostly, the combination of both enhance vocal performance. As observed in the literature, the theoretical approach on vocal production and factors that can cause damage or contribute to the maintenance of vocal disorders is common, as clarifications and knowledge of the functionality of the vocal apparatus can make teachers to better understand the production of their voice and take more care for vocal well-being.

Research conducted with the aim of "analyzing the educational processes of the collective actions of the vocal health of the teacher described in the Brazilian speech therapy literature", through a literature review, highlighted that themes and contents such as vocal habits/behaviors and hygiene care/vocal health are present in about 71% of Brazilian publications, being the most prevalent theme20.

In a research11 that sought to compare the effectiveness between vocal guidance and the application of vocal techniques, respectively, indirect and direct vocal training, concluded that when the intervention is conducted combined (direct and indirect) results are more significant, regarding the parameters of vocal quality and voice self-assessment.

The studies included in this review present both approaches as an intervention process in their programs, which agrees with the literature. The study by Bovo et al.19 specifies, among the theoretical content, subjects such as vocal anatomy and physiology, etiological factors for dysphonia, medication use, and vocal fold injuries. The study by Simões-Zenari and Latorre15, in addition to the items covered by the study previously mentioned19, brings as theoretical content the concepts of normal, adapted and altered voice, vocal psychodynamics, vocal plasticity, non-verbal communication, body and voice, in addition to addressing the importance of listening and the use of physical space in an appropriate way to favor the voice, including the concept of vocal well-being. Luchesi et al.16 also addressed phonation anatomy and physiology, as well as themes related to vocal health, involving habits and vocal care.

Thus, vocal health actions aimed at the teacher are considered essential practices for preventing vocal disorders since they assist and guide professionals on the use of voice in the workplace and provide understanding about voice care21.

The intensification of preventive actions is increasingly necessary and allows significant vocal behavior changes, favoring reflections and sensitization by teachers and managers and generating adaptations in the work environment14.

An important aspect in any process of caring for the teachers' vocal health, especially to assess the effects of an intervention, is to conduct an assessment at the beginning and end of actions aimed at this population. Silvério et al.14 highlighted each stage of their intervention, specifying as a first step the realization of a perceptual-auditory analysis interview, in addition to a laryngological assessment. Such a process allows a good knowledge of the participants' vocal condition at the beginning of the intervention and a good analysis of the effect of the experience at the end. The initial assessment process consists of the initial step in any speech therapy intervention process.

The auditory-perceptual evaluation of the voice is considered the gold standard in the vocal clinic, and in many cases it is accompanied by an acoustic evaluation, considered an objective evaluation. In addition to these, vocal self-assessment protocols to verify the impact of a vocal alteration on teachers' daily lives are used as auxiliary instruments in the vocal assessment process.

The evaluations of the results of the studies interventions included in this review were performed using various instruments, such as protocols and scales of perceptual analysis of the voice (using the GRBASI scale), acoustic analysis and auditory self-perception protocol, questionnaires, group conversations, registration in a specific protocol, VHI questionnaire and vocal assessment. However, in one of the studies16, the instrument used to measure the effectiveness of the intervention was not presented.

The auditory-perceptual assessment was mentioned in two studies14, 18 as the chosen instrument to assess the interventions' outcomes. Another study mentioned the use of acoustic evaluation and the Voice Handicap Index (VHI) questionnaire, indicated for assessing perception concerning the disadvantages that dysphonia can cause and serves as an instrument to monitor the effectiveness of treatment for vocal changes22. Simões-Zenari et al.15  and Xavier et al.17 used their own questionnaires, designed specifically for their research, without using existing validated instruments or protocols.

Assessments regarding the involvement of the voice in teaching activity and quality of life are important instruments for measuring the impact of the voice on the social, emotional, and personal aspects, which allows a better understanding of the impact of a vocal change on daily life subjects. Several studies call attention to look at the emotional aspects regarding vocal changes in teachers3, 5, 23, which can compromise their work activities' performance.

In a study developed to evaluate vocal quality, self-assessment, and quality of life in elementary school teachers' voices, the authors concluded that vocal well-being programs could facilitate understanding the vocal problem. It can also awaken to a more improved self-assessment, making it possible to minimize the installation of a vocal disorder that leads to removing the teacher from the classroom3. The lack of knowledge about the own voice and the difficulty of perception can increase vocal impact24.

As mentioned earlier, the approaches used in the prevention/promotion of teachers' vocal health programs should include theoretical and practical content. Among the practical contents addressed, the strategies involving relaxation, breathing, and vocal projection were highlighted15, 16, 18.

According to research in the professional voice area, especially those related to the teachers' voice, it is highlighted that teachers need vocal projection and resistance to conduct their activities12.

The practical contents consisted of postural exercises, relaxation exercises, breathing15, 16, 18, vocal resonance and projection15, 16, 18, speech articulation15, 16, speech modulation and speed16, vocal resistance15, vibration exercises15, cervical stretching15, verbal and non-verbal expressiveness16. Such sequence is considered crucial when planning work to promote vocal well-being, prevention, and vocal rehabilitation.

Relaxation, breathing, resonance, and vocal projection, mentioned as fundamental in work with teachers, promote the reduction of effort and relaxation of specific muscles involved with the phonation process, increased breathing capacity, in addition to resistance and voice projection.

The breathing in the vocal clinic is highlighted since this function is necessary to set the vocal folds in motion. However, when it comes to the teachers' voice, it is vital to work on the respiratory type and pneumophonoarticulatory coordination since upper or thoracic breathing promotes greater pharyngeal tension and insufficient air supply. This can cause tension in the cervical region and change the professional vocal performance, like in teachers8.

The work with resonance and vocal projection exercises allow a resonant and muscular balance, assist in glottal coaptation and promote the sensation of sound vibration on the face and vocal projection.

Besides these exercises, facilitating sounds, such as fricative sound techniques and vibrant sound techniques, favor a balanced vocal production. Exercises involving articulation of speech sounds are also essential to promote a more balanced vocal production, articulatory precision, and vocal projection. These exercises deserve to be highlighted as elected and described by the studies included in this review as strategies to integrate a program to promote and prevent the teachers' vocal health.

Orientations regarding vocal warm-up and cool-down programs are constant in the teachers' vocal health programs.Among the studies included, two15, 16 mention these strategies specifically.

In the case of vocal warm-up and cool-down, research was conducted with the objective of "identifying and describing methodological parameters and the effects of proposals for vocal warm-up and cool-down described in national and international literature". The authors concluded that such techniques allow a better vocal performance to the spoken voice professionals and that there is no agreement regarding the execution time and the exercises used25.

The variables time of sessions, exercises used, and execution time are wildly divergent between studies in the voice area.The analysis of the included studies shows that the number of meetings and the time used in the interventions are variable, characterizing the heterogeneity in the intervention, with different methodologies, impacting the summary analysis to evidence the results.

In the study developed by Chan18, the intervention continued for two months, not specifying the number of meetings, with sessions of 1 hour and 30 minutes each meeting. In another study14, 12 meetings were held 1 hour each. In the study by Simões-Zenari and Latorre15, 12 hours of total intervention were also spent, divided into five meetings, where the first 4 hours were used, and the remaining four were 2 hours each. One study16 held 12 meetings with 1 hour and 30 minutes each, reporting that the participants had reduced vocal symptoms at the end of the intervention. In another study17, the authors reported having conducted six workshops with biweekly meetings but did not specify the time spent in each one.

Among studies that specified the time spent per meeting and the number of meetings, an average of 14 hours was used with the interventions, which can be considered favorable results with the theoretical and practical activities to promote the teacher's vocal health. One study16 reported a total time of 18 hours, with meetings of 1 hour and 30 minutes each, session time also used by another researcher18, but it was not possible to total the workshop time in the latter.

Educational programs for promoting teachers' vocal health are the most repeated. These are important for greater participation by teachers. Through these interventions, there is an increase in the knowledge of speech therapy strategies to reduce vocal impact, decreasing the present symptoms related to the voice9, 26.

Vocal hygiene, breathing exercises, warm-up, and vocal cooling are mentioned in the interventions as a form of important practical activities for the teacher since it will favor vocal health and prevent the appearance of changes and laryngeal diseases due to bad vocal use and abuse27.

Thus, the strategies used in programs related to the teacher's vocal health are grouped into theoretical and practical intervention categories. As for the theoretical ones, the themes address subjects related to vocal physiology, etiological factors, vocal habits, breathing and voice, verbal and non-verbal expressiveness, vocal warm-up and cool-down. Among the practical approaches, straw phonation, strategies involving the semi-occluded vocal tract, breathing exercises, vocal projection, the articulation of speech sounds, vocal resistance, relaxation and CPFA, exercises that include strategies for warming up and working out and vocal cooling, are performed.

This study agrees to a similar one that concluded that the best, regarding the prevention and treatment of the teachers' voice, is to combine theory with practice in intervention programs11.

In the included studies, it was observed that the target audience still focuses on teachers of kindergarten and elementary education, with little or no participation of teachers from high school.

From the realization of this research, there is an undeniable need for more studies that, notably, bring more contributions about the topic at hand in the presentation of strategies to promote the vocal health of the teacher, setting the minimum time for effective application of the program, as well as strategies that allow for the effectiveness and adoption of instruments that enable the unsuspected evaluation of outcomes.

The present work may have limitations due to the number of studies included. This fact is mainly due to the selection strategies adopted in this review, which may have excluded some other important studies.

Conclusion

This study allowed us to identify a diversity of strategies used in vocal health programs/actions for teachers, besides heterogeneity in the number of sessions and variations in techniques, which resulted in improved vocal assessment scores at the end of the program. Some studies followed the teachers for a period after the program and found that satisfaction with the voice was maintained, showing a positive effect of the programs/actions. However, it would be essential to use objective instruments and subjective assessment or standardized protocols for measuring training results.

As for strategies, theoretical and practical approaches are part of the teachers' vocal health promotion program/actions with an emphasis on theoretical topics, such as anatomy and physiology of vocal production, vocal hygiene, and, for practical aspects, exercises involving the objectives of working relaxation, breathing, resonance, and vocal projection.Guidance on vocal warm-up and cool-down is also noteworthy. They are often present in programs and actions of guidance.

The results of the approaches presented and discussed here proved to be effective strategies for better vocal performance of teachers, who report vocal comfort and minimizing vocal effort during their work activities.

Additional information

Conflicts of interest: No conflicts of interest declared concerning the publication of this article.

Indications about the contributions of each author:

Conception and design of the study: EPGM, VFAP

Analysis and interpretation of data: EPGM, RMS, MSC, VFAP Data collection: RMS, MSC

Writing of the manuscript: RMS, EPGM

Critical revision of the article: VFAP

Final approval of the manuscript*: EPGM, RMS, MSC, VFAP

Statistical analysis: Not applicabe

Overall responsibility: EPGM

*All authors have read and approved of the final version of the article submitted to Rev Cienc Saúde.

Funding information: Not applicable.