In the present study, the mean scores ranged between 75.6 and 92.5 in the control and experimental groups in the pre- educational program situation. In the study conducted by Spina et al. , when the quality of life and voice were correlated with levels of dysphonia and professional activity, scores from 71 to 100 points of the V-RQOL were found for individuals with better quality of life and from 0 to 35 points for the group with worse quality. In the V-RQOL validation study, used for dysphonic individuals, means of 53.5 for the total score, 55.9 for the socio-emotional domain and 51.9 for the physical domain were found, whereas for individuals with a normal voice all the scores were over 70 .
The mean scores of the present study suggest that the quality of life of the subjects was not being interfered with by dysphonia, since the V-RQOL scores were found to be relatively high and close to 100. Although subjects of this sample, both the control and experimental, have reported signs and symptoms for dysphonia, they do not associate these symptoms as negatively impacting on quality of life. The results corroborate the findings of Grillo and Penteado (2005) who studied the impact of voice on the quality of life of primary school teachers. This leads one to reflect on the need for self-perception of teachers as regards use of the voice in day-to-day routine, as well as the impact that vocal alterations and health problems may have on their quality of life.
Possibly there is greater need for these professionals to identify their respective voice problems, which may interfere in their day-to-day activities. Although the focus of the educational program did not contemplate training for auditory self perception of the voice and vocal psychodynamics, these aspects may be suggested for application in future vocal health programs for teachers.
After the educational activities, teachers showed significantly higher domain and overall V-RQOL scores after preventive intervention, in both control and experimental groups, showing that these activities had a positive impact on the participants’ lives. This shows that both the activities provided with guidance on vocal hygiene, and those including practice of the exercises reflected positively on the quality of life of subjects.
It is important to point out the importance of educational actions on teachers’ vocal health, reflecting on the individuals’ quality of life. It is known that instructions such as taking care of hydration and perceptive measures such as, for example, not shouting in the classroom and not speaking with strong intensity in the presence of noise may improve the teacher’s vocal quality . Hydration promotes and maintains healthy functioning of the larynx, especially in individuals that use the voice professionally . On the other hand, dehydration may increase phonatory effort, contributing to the manifestation of vocal fatigue, particularly for professionals who use the voice as an instrument for work . Instructions about the habit of drinking water during the professional routine were worked on in this study in both groups, by means of lectures, discussions on the subject among the participants, explanatory folders and a 30 ml bottle offered to each participant to use for drinking water during day-to-day work. Other educational measures were also transmitted, such as not shouting, but drawing the pupils attention by means of other resources such as clapping their hands or using a whistle. Emphasis on the practice of changing to healthy behaviors for the voice in both groups positively favored the quality of life of participants, observed in the global dominion score of the V-RQOL.
The present study differs from other educational programs in which they verified improvements in the quality of life of the participants in educational programs, but only evaluated in situations of vocal training exercises [7, 15, 21]. The fact that 2 lecture sessions were developed on vocal hygiene habits in the control group, in addition to the resource of offering a botttle of water, differs from the methodology of other studies. These studies approached the subject of vocal hygiene habits in a single session only for the control group [7, 9, 10].
Various authors have mentioned the biopsychosocial impact in the face of voice problems that affect teachers [6, 21]. Studies have shown that when evaluating the impact of educational programs for voice professionals by means of protocols with measurement of qualitative and quantitative measures, it was possible to observe a significant improvement with regard to physical and emotional aspects in general [7, 21]. These effects were better observed in intervention programs related to voice training exercises associated with vocal hygiene habits [7, 9, 22]. In the present study there was improvement in the aspects of vocal health, intensifying the improvement of physical and psychic well being both in the control and experimental groups.
Studies have shown that educational actions of a preventive nature, when developed in groups and in the work environment may improve the quality of life of workers, particularly in physical and psychic well being [4, 22–24]. Researchers have indicated that the fact of an individual participating in group educational activities with persons who have similar problems and difficulties favors improvement in psychic well being, providing a reduction in stress and anxiety at work and improvement in communication . A hypothesis for the findings of reduction in anxiety and frustration of individuals faced with voice difficulties, observed in the present study, may be that the dynamics of discussing the subjects raised in groups, provided a support network among the teachers. Timmermans et al. (2004)  observed significant chance in the emotional aspects of voice professionals who participated in an educational program with instructions about vocal hygiene and in situations of vocal training exercises, in addition to verifying an improvement after 18 months with regard to psycho-emotional aspects, both in the group given vocal hygiene instructions and the group with training exercises, concluding that this improvement, for both groups, reflected maturation as regards self perception and better control of feelings over the course of time.
In the present study, statistically significant difference was observed for the physical score of the V-RQOL for both the control and experimental group. The findings differ from those of the study of Duan et al. (2010), who evaluated the quality of life of subjects who participated in a vocal health program. There was a report of improvement in the physical and functional aspects of the voice only in the experimental group. These authors provided a lecture on vocal hygiene for the control and experimental groups, in addition to 4 sessions of training exercises for the latter group. Although the number of intervention sessions applied to the control and experimental group in the study of Duan et al. (2010) are compatible with those of the present study, the findings for the control and experimental groups obtained statistically significant results in the final evaluation of the physical score. It is suggested that in the present study, the physical improvement reported by the control group is due to the emphasis on healthy practices for the voice, reinforced in two lectures. The fact of instructing teachers about drinking water during the time they are giving lessons may result in beneficial effects when they are incorporated by the subjects, due to the reduction in friction between the vocal folds and in the reduction of the effort to speak. The same educational practices were discussed in the experimental group, and the teachers were encouraged to practice them together with the training exercises.It is suggested that the instructions transmitted were assimilated in good part by the teachers in both groups, which may result in positive effects on the improvement of the physical and functional aspects of the voice.
In general terms, although we found no difference intra and inter groups for each question of V-RQOL, we see a pattern of change to higher percentages for the categories never and hardly to the two groups, suggesting educations actions, can improve the quality of life of the subjects in relation to biopsychosocial aspects, such as improvement in psychological aspects, in communication and in the activities related to work.
One of the interesting points of this study was the randomization process. Initially, schools were randomly selected and then a general questionnaire, concerning socioeconomic and professional information, was applied to all teachers. Based on the results, we found no differences between the characteristics of teachers in different schools. Thus, there was the final draw of the schools, divided into experimental and control groups. This option was due to the fact that teachers have their workload too long (most with more than 32 hours/week) and they have only 2 hours/week available for meetings, part of this time in which the activities were carried out the study. In practical terms, it would be almost impossible to divide the sample into two study groups for ethical and logistical reasons. This form of randomization was similar to the study of Pasa et al. (2007), randomization of the sample of schools to compose groups, and different of other studieswhich the total sample of selected individuals was randomized between control and experimental group [7, 8, 21].
A limitation of this study is related to the number of male included in the experimental group (n = 7), and this is explained by low number of male teaching in public schools (less than 15% of the total) and low level of adhesion by male in the selected schools. However, due the fact men are less exposed to vocal problems than women due to the larynx and vocal folds conformation, this could exert a little impact on results. Another potential limitation was the limited number of vocal exercise sessions (4), possibly being a bias to identify gains in the voice quality longitudinal. The sessions of vocal health program was only possible to be realized in the form of separate schools, it was possible to gather all who were part of the same group at a single time and place.
Thus, it is important for future vocal health programs for teachers envisage the inclusion of both educational activities with vocal hygiene instructions and specific training exercises to obtain and improvement in the quality of life of subjects. This shows that there is a need for partnership between the public health area and the educational area, so that inter-sectorial actions promote quality of life at work, specifically for teachers.