ASSOCIATION BETWEEN TEACHING EXPERIENCE AND VOICE SELF-ASSESSMENT AMONG PROFESSORS : A CROSS-SECTIONAL OBSERVATIONAL STUDY Associação entre o tempo de magistério e a autoavaliação vocal em professores universitários : estudo observacional transversal

Conflict of interest: non-existent Researches4-6 have revealed that these risk factors are harmful to teachers’ health, leading to musculoskeletal, vocal, and respiratory issues that negatively impact their quality of life, i.e., their voice is vulnerable to time and inappropriate use7. According to the 3rd National Council on Professional Voice, diseases related to the vocal tract either deriving from or detrimental to work have effects at the social, economic, professional, and personal levels. Therefore, besides leading to voice sensations/symptoms, vocal disorders may negatively impact teachers’ performance and quality of life8. Researches on teachers’ health have been carried out mostly in kindergarten, elementary school, and high school given the prevalence and risk factors to which these professionals are exposed1. On the other hand, few studies are carried out with professors since they enjoy good work organizational and environmental conditions. However, changes over the past 20 years in work  INTRODUCTION


INTRODUCTION
Considered a relevant factor in human socialization, voice impacts people's quality of life, especially of those who use it professionally. For this reason, research on the professional use of voice has received increasing attention in recent years 1 .
Teachers are the voice workers with the greatest predisposition to develop voice disorders 2 . This occurs due to inappropriate working conditions and to the prolonged, intense use of the voice 3 .
The protocol contains five sections: selfassessment of vocal issue severity, effects on work, effects on daily communication, effects on social communication, and effects on expressing emotions. The tool uses a 10 cm analog visual scale (AVS) ranging from "regular" to "intense" in the first question and from "never" to "always" in the others. The maximum score for a question is 10 and the maximum total score is 280, which reflects the greatest negative impact of a vocal issue. Two additional scores were calculated: The Activity Limitation Score, by adding up the scores of the ten even-numbered questions of the aspects "work," "daily communication," and "social communication" (questions 2, 4, 6, 8, 10, 12, 14, 16, 18, and 20), and the Participation Restriction Score, by adding up the scores of the ten odd-numbered questions of those same aspects (questions 3,5,7,9,11,13,15,17,19, and 21).

Statistical analysis
Data normality was verified through Shapiro-Wilk test, which showed no Gaussian curve. Thus, the data were expressed as median, interquartile range (25-75), and minimum and maximum to describe the sample in the present study. Teaching experience and the VAPP scores were associated through Spearman's coefficient of correlation. Correlation was considered higher the closer to 1 or -1 it was for positive/direct or negative/inverse correlations, respectively. All analyses used the software Statistical Package for Social Sciences (SPSS) version 19.0 at a 5% significance level (p≤0.05). Table 1 shows the sample's characteristics with age, teaching experience, and gender.

RESULTS
The most commonly reported vocal symptoms when the questionnaire was applied were throat dryness (66.6%) and hoarseness (40.4%). Table 3 shows a grouping every 5 years indicating the number of professors who work at given periods, expressed as absolute and relative frequencies. Table 4 shows the results of the domains and total VAPP score as reported by the participants. Table 5 shows Spearman's coefficient of correlation for the association among the domains and between the total VAPP score and teaching experience, which showed no significant correlation. The effects of domains on daily communication and on social communication, participation restriction score, and total score were negatively, or inversely, correlated. organization in universities have caused greater psychological strain with various working demands, both those pertinent to teaching itself and the ones related to competitiveness and recognition in the academy 9 .
Some instruments have been developed aiming to verify the impact of voice changes on quality of life. In Brazil, there currently are three important instruments that have been translated, adapted, and validated: the Voice-Related Quality of Life (V-RQOL) questionnaire, the Vocal Activity and Participation Profile (VAPP) protocol, and the Voice Handicap Index (VHI). V-RQOL is considered a self-assessment protocol that is easily and quickly applied, VAPP can be used to map areas more affected by dysphonia on quality of life; while VHI assesses the handicap a dysphonic person experiences 10, 11 .
Taking into account how complex the subject of quality of life and voice issues is, this study aimed to assess the association between teaching experience and voice-related quality of life among professors.

METHODS
The present observational cross-sectional study was approved by the Research Ethics Committee of the Federal University of Healthcare Sciences of Porto Alegre under protocol 075/05 in July 23 rd , 2011.
The sample consisted of 42 professors of the Federal University of Healthcare Sciences of Porto Alegre, who received an e-mail inviting them to take part in the research. Those who fit the inclusion criteria joined the sample. The following inclusion criteria were considered to select the subjects: Working as a professor for 40 weekly hours, having complains related to professional voice use, and signing the term of free and informed consent.
Regarding hearing loss information, the subjects were asked about their last hearing assessment and only one participant was excluded. Those who either had undergone or were undergoing any treatment for vocal disorder or voice enhancement were excluded.
First, the researcher applied a questionnaire to characterize the sample and identify voice sensations/symptoms. Next, the subjects answered the 28 items of the Vocal Activity and Participation Profile (VAPP) protocol 12 , which assesses the perception of a voice issue regarding the limitation in activities and restriction in participation based on the concept of the International Classification of Functioning, Disability, and Health (ICF) of the World Health Organization (WHO).    The VAPP protocol was chosen for being easily understood and applied, besides being comprehensive and covering several aspects not approached by other tools such as effects on work, which is the focus of this study.
The total VAPP score shows that the total score and the domains are below the values found in other researches 1,11 . Although the subjects did report voice complaints, these have not limited their work-related and daily activities. However, the authors highlight the importance of offering voice-health programs for the reduction of vocal symptoms and of training teachers for the appropriate use of their work tool. Teaching experience and the domains and total VAPP score were not significantly correlated. These results indicate that, in the sample studied, the time during which the subjects have been using their voices professionally has not compromised voicerelated quality of life yet. On the other hand, studies carried out with elementary school teachers 18,19 using quality of life and voice protocols showed that the longer the teaching experience, the more negative the individual's perception is regarding their physical, psychological, and social status.
It must be pointed out that the sample studied is heterogeneous with a broad variation in data, which partially justifies the lack of correlation between teaching experience and vocal self-assessment. Nevertheless, there was no intention of reducing or limiting the sample in order to show the reality of the staff of the university at hand.
T h e authors highlight how important it is to use protocols that enable the individuals to reflect on their own voices, since, besides contributing to a better vocal assessment dimension, the patients' opinion on their own well-being must be taken into account to understand the actual perspective of the impact of a disease.

DISCUSSION
Women made up the majority of the sample in this study, as is the case with voice-related national and international researches 13-15 on teachers, which that also show that most teachers are female. Moreover, women have a higher prevalence of voice problems due to the requirements of using their voices professionally 13,14 .
The age variable deserves due attention since vocal efficiency decreases as age advances. According to the literature, the age group between 25 and 45 years old is expected to have the best vocal efficiency, i.e., after this period a series of structural changes take place in the larynx that can impact voice quality 15 . In the sample studied, age ranged from 26 to 59 years and few subjects were above 45 years old, the point at which age-related voice changes may begin 4,16 .
Regarding teaching experience, most professors were young both in age and career, with a median of 8.5 years. The authors did not set a minimum limit for inclusion in the research. According to the literature, both teachers beginning their careers and those with more experience require voice health counseling, which should begin at their undergraduate courses 2 . In this study, the professors showed great interest in taking part in the research, which is important because it suggests they are aware of how important their voices are for work.
Among the voice complaints reported, the most common were throat dryness and hoarseness. The same was found in other researches 11,17 at similar rates as the ones in this study. This finding is explained by the unfavorable work conditions such as strong competitive noise, classrooms with inappropriate acoustics, tension when speaking, lack of knowledge of appropriate vocal techniques, and lack of vocal hydration. activities yet. Moreover, no association was found between teaching experience and the domains and total VAPP score, i.e., the time using the voice professionally does not compromise voice-related quality of life in this sample of professors.