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Vocal Fatigue Symptoms and Laryngeal Status in Relation to Vocal Activity Limitation and Participation Restriction
Vocal Fatigue Symptoms and Laryngeal Status in Relation to Vocal Activity Limitation and Participation Restriction *Irma Ilomäki, *,†Elina Kankare, *Jaana Tyrmi, †Leenamaija Kleemola, and ‡Ahmed Geneid, *†‡Tampere, Finland Summary: Objectives. The study aims to investigate the vocal fatigue symptoms and laryngeal status in relation to vocal activity limitations and vocal participation restrictions. Study Design. This is a case-control study. Methods. Two hundred six teachers were divided into two groups based on the frequency of their self-reported vocal symptoms being more or less than the mean of reported frequency. The study compared odds for activity limitation and participation restriction in relation to frequency of vocal symptoms, number of vocal symptoms recurring weekly, and organic laryngeal changes. Activity limitation and participation restriction were studied using the Voice Activity and Participation Profile questionnaire. Results. Increased odds were found for teachers with frequent vocal symptoms and especially those with one or more vocal symptom recurring weekly. Odds were found to be 2.6–8.5 times more likely in teachers with more frequent vocal symptoms. The odds increased dramatically with increase of the number of vocal symptoms recurring weekly. Laryngeal organic changes were found to increase the odds but insignificantly. Conclusions. Teachers with frequent vocal symptoms, especially those with vocal symptoms recurring weekly, have increased odds ratio for vocal activity limitation and vocal participation restrictions. High scores or frequent occurrence of self-reported vocal fatigue symptoms must be taken seriously in the evaluation of vocal working ability. Key Words: Evaluation of vocal working ability–Frequent vocal fatigue symptoms–VAPP–Laryngeal examination– Teacher’s voice.
INTRODUCTION High prevalence of symptoms of vocal fatigue and increased risk for voice disorders have been found in teachers.1–4 However, their potential effects on limiting the vocal activity and restricting the vocal participation are still to be investigated. The consequences of voice problems may be vocal, professional, or socioeconomic. Voice problems may lead to limitations in work and social life, absenteeism, and financial loss.5–7 Because voice is the primary tool of instruction in the classroom, it is essential that the pupils can hear and understand the teacher without difficulty. Pupils have shown weaker learning outcomes when listening to a teacher with dysfunctional voice8–10 as impaired vocal quality adds listeners’ processing load and processing time.11 Therefore, it is important to find out how vocal symptoms are associated with teachers’ ability to do their vocal work and to participate in work and daily life. Very frequently occurring vocal symptoms are considered to be a serious condition of vocal fatigue in teachers. Sala et al1 defined two or more self-reported weekly or more often occurring symptoms to be a borderline of significant voice disorder. The present study investigated this and also different numbers of frequent symptoms to find out how they contribute to teachers’ Accepted for publication July 26, 2016. From the *Speech and Voice Research Laboratory, School of Education, University of Tampere, Tampere, Finland; †Department of Otorhinolaryngology and Phoniatrics, Tampere University Hospital and School of Medicine, University of Tampere, Tampere, Finland; and the ‡Department of Otolaryngology and Phoniatrics—Head and Neck Surgery, Helsinki University Hospital and University of Helsinki, Tampere, Finland. Address correspondence and reprint requests to Irma Ilomäki, Speech and Voice Research Laboratory, School of Education, University of Tampere, Tampere 33014 Finland. E-mail: [email protected] Journal of Voice, Vol. 31, No. 2, pp. 248.e7–248.e10 0892-1997 © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.jvoice.2016.07.025
voice-related activity limitation (AL) or participation restriction (PR). AL and PR may deteriorate teachers’ vocal working ability and voice-related quality of life. Additionally, this might indirectly affect pupils’ possibilities of equal learning in those teachers’ classrooms. Based on World Health Organization’s ICIDH-2 International classification of impairment, disability and handicap-Beta1, with concepts “activity limitation” (instead of their previous term “disability”) and “participation restriction” (previously “handicap”) (ICIDH-2 Beta 1, WHO 199712), Ma and Yiu13,14 have developed an assessment tool, which is the Voice Activity and Participation Profile (VAPP), for evaluation of vocal functioning. The VAPP is a self-evaluation questionnaire about the effects of vocal symptoms on occupational and other daily activities and functioning,13 with a validated Finnish version.15,16 It provides information about the impact of voice on the life and working ability of the individual. The VAPP is composed of 28 questions, divided into five sections: self-perception of the vocal problem severity (one question, maximum score of 10) and the effects of voice problems at work (four questions, maximum score of 40), daily communication (12 questions, maximum score of 120), social communication (four questions, maximum score of 40), and expression of emotions (seven questions, maximum score of 70). Besides these, the sum scores of AL and PR are calculated. AL is calculated by the sum of all even questions of sections 2–4 (work, daily communication, and social communication) and PR by the sum of all uneven questions of these three sections. The AL questions consider, eg, voice user’s difficulties to become understood in conversations or heard in noisy situations due to voice problems. PR is assessed, eg, by questions about avoidance of speaking or unwillingness to take part in communication situations because of one’s voice problems. The maximum scores
Irma Ilomäki et al
Vocal Fatigue Symptoms and Laryngeal Status
on both AL and PR are 100; higher score means worse situation in voice use. Ma and Yiu13 define “activity limitation” as constraints imposed on voice activities, and “participation restriction” as reduction or avoidance of voice activities by an individual. The VAPP questionnaire was used in the present study because it presents the attempt to capture the effects of voice problems on occupational activities. Vocal symptom questionnaires have varied in previous studies.1–3,17,18 Most common questions for teachers have concerned, eg, hoarseness, increased effort, difficulty in being heard, voice breaks, aphonia, and feelings of physical discomfort such as feeling of lump or pain in the throat. The number of separate symptoms asked has varied from 6 to 16. For example, Sala et al1 asked about seven symptoms: throat clearing, voice tires easily, hoarseness, sore throat or globus, voice breaks, difficulty in being heard, or aphonia. The 4–6 point prevalence scales have varied from “no symptoms/hardly ever” to “very frequently occurring/weekly/daily” symptoms. In the present study, a symptom questionnaire of eight questions evaluated with 4-point scale (“hardly ever/occasionally/monthly/or weekly”) was developed on the basis of previous studies. The instructions given for filling the questionnaire were to think of a situation where a voice user has used his or her voice for a relatively long time, ie, to report the symptoms that could be the result of voice fatigue. METHODS The participants of the study were 206 female kindergarten and primary school teachers (116 kindergarten teachers, 90 primary school teachers). The mean age of the teachers was 42.4 ± SD 8.9 years, and the mean year in profession was 16.4 ± SD 9.4 years. Other aspects of the data have been reported earlier.19–21 Laryngeal status of the participants was assessed by experienced phoniatricians in schools and kindergartens through indirect laryngoscopy. Organic laryngeal changes showed in 45% of the subjects studied. Obvious organic laryngeal changes, such as vocal fold nodules, polyps, chronic laryngitis, or vocal fold atrophy, were found in 11%. Mild organic changes, such as mild vocal fold or arytenoid edema and mild closure incompetence, were observed in 34%. The rest, 55% of the teachers, were without organic laryngeal changes. The details of assessment of laryngeal status have been documented in earlier studies.19,21 In the self-evaluation questionnaire, the teachers were asked eight questions about the frequency of their possible vocal fatigue symptoms: strainedness, mucus in the throat, irritation in the throat, pain in the throat, hoarseness without infection, voice breaks, aphonia without infection, and vocal fatigue causing troubles in social life after a working day. They were instructed to think of a situation where they have used their voices for a relatively long time. The assessment scale was a 4-point scale with prevalence of symptoms being “hardly ever/ occasionally/monthly/or weekly.” The incidence of vocal symptoms was then scored in five of the questions (strainedness, mucus in the throat, irritation in the throat, pain in the throat, and hoarseness without infection), with scores of 0 “hardly ever,” 2 “occasionally,” 4 “monthly,” and 7 “weekly,” with a subscore of 35 in total. Three of the questions (voice breaks, aphonia without infection, and vocal fatigue causing troubles in social
248.e8
life) were scored using some emphasis on the statements which were considered to illustrate more serious voice problems (0 “hardly ever,” 3 “occasionally,” 5 “monthly,” and 8 “weekly,” with a subscore of 24). The combined total score was 59. The mean vocal symptom score of all teachers was 24.3 (41.2% of maximum score). This average was used to divide the teachers into two subgroups based on their scores of vocal symptoms mentioned before. The subjects with scores more than the mean of the whole group were regarded as cases of the study (group A), whereas the subjects with scores less than the mean were regarded as the control (group B). Accordingly, subgroup A serves as the group with subjects with many complaints, whereas subgroup B is the group with fewer complaints. Such dichotomized method was used to study the AL and PR correlates in addition to the differences between the two groups. In addition, the number of symptoms occurring weekly was also calculated by summing the number of symptoms per week, being one or more (1+), two or more (2+), three or more (3+), or four or more (4+) symptoms occurring weekly. The number of symptoms occurring weekly was studied in correlation with AL or PR derived from the VAPP. Statistical analyses were carried out using the IBM SPSS Statistics 21.0 software for Windows (SPSS Inc., Chicago, IL). Odds ratio (OR, ratio of the probabilities of an event happening to that of it not happening) was calculated with Risk Estimate in Crosstabs and statistical significance of group differences with binary logistic regression. OR was used to determine whether a particular exposure (in this study: higher score or more frequent symptoms) is associated with/is a risk factor for higher AL or PR, and to compare the magnitude of risk factors with that outcome. A significance level of 0.05 (5%) was considered for all the analyses, and all the reliability intervals were based on 95% confidence interval (CI). As to the interpretation of odds results, OR = 1 shows that exposure does not affect odds of outcome, OR > 1 exposure is associated with higher odds of outcome, and OR < 1 exposure is associated with lower odds of outcome. RESULTS The odds for AL and PR in teachers with or without organic laryngeal changes were OR = 1.3 (95% CI: 0.82–1.5) for AL, and OR = 1.1 (95% CI: 0.78–1.4) for PR. These results showed that organic changes are associated with higher odds of AL or PR, but this remained statistically insignificant. Subgroups A and B were compared in terms of AL and PR. Subgroup A, which had higher scores (frequency) of vocal symptoms, showed 3.7 times more likely activity limitation (OR: 3.7, 95% CI: 2.0–6.8, P < .0001) and 2.6 times more likely participation restriction (OR: 2.6, 95% CI: 1.5–4.7, P = 0.0012) than subgroup B. Both results were statistically significant. The number of vocal symptoms recurring weekly and reported by the teachers was studied. Of the 206 teachers, 73 (35%) reported one or more (1+) weekly symptoms, 50 (24%) two or more (2+), 35 (17%) three or more (3+), and 24 (12%) of the teachers reported four or more (4+) weekly symptoms. One hundred thirty-three (65%) of the teachers did not have weekly recurring symptoms. The details of odds for AL based on the
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Journal of Voice, Vol. 31, No. 2, 2017
TABLE 1. Odds for AL among Teachers Based on the Number of Weekly Recurring Vocal Symptoms Number of Weekly Recurring Symptoms
% of 206 Teachers
Odds Ratio for AL
95% CI
P-value
1+ weekly 2+ weekly 3+ weekly 4+ weekly
35 24 17 12
3.5 4.6 5.2 8.5
1.9–6.5 2.2–9.6 2.1–12.7 2.4–29.8
P = 0.0001 P < 0.0001 P = 0.0003 P = 0.0008
All odds ratios were statistically significant. Abbreviations: AL, activity limitation; CI, confidence interval.
TABLE 2. Odds for PR among Teachers Based on the Number of Weekly Recurring Vocal Symptoms Number of Weekly Recurring Symptoms
% of 206 Teachers
Odds Ratio for PR
95% CI
P-value
1+ weekly 2+ weekly 3+ weekly 4+ weekly
35 24 17 12
2.8 4.5 5.1 6.0
1.5–5.1 2.2–9.3 2.1–12.5 2.0–18.2
P = 0.0001 P < 0.0001 P = 0.0003 P = 0.0002
All odds ratios were statistically significant. Abbreviations: PR, participation restriction; CI, confidence interval.
number of weekly recurring vocal symptoms are shown in Table 1 and odds for PR in Table 2. DISCUSSION Higher scores or the number of weekly symptoms of vocal fatigue were associated with increased vocal AL and PR. Subgroup A teachers with higher symptom scores showed increased AL 3.7 times more likely and PR 2.6 times more likely than subgroup B teachers with lower scores. The odds for higher AL and PR also increase with the number of symptoms recurring weekly; these were 2.6–8.5 times more likely in teachers with one, two, three, or four weekly symptoms. Thus, the consequences of the higher number of vocal symptoms or increase in symptoms recurring weekly are clearly associated with limitation of vocal activities and restriction of participation that are based on World Health Organization’s International Classification of Functioning and Disability (ICIDH-2 Beta 1, WHO 1997). A study by Sala et al1 suggested that two or more weekly recurring vocal symptoms, regardless of the symptom, may be a borderline for diagnosis of significant voice disorder. Our results point to the fact that even one symptom recurring weekly increases the odds for limitation in vocal activities and participation. Such finding may indicate the situation of significant voice disorder and might be suspected as a threshold, which is less than the one reported by Sala et al.1
Laryngeal organic changes were quite common. Obvious or mild changes were found among 45% of our studied teachers in comparison to previous studies; for example, SliwinskaKowalska et al22 found voice disorders in 32.9% of the teachers and Sala et al1 in 29%. Odds ratios for AL or PR were higher among the teachers with organic changes but still remain statistically insignificant. It is possible that the teachers with such changes are to a certain extent aware of the problems with their voice and tend to use it in a controlled way21 that does not end in raising the odds significantly for vocal activity limitation and vocal participation restrictions. Sulica23 analyzes the selfevaluation of voice in relation to the clinical evaluation and points out that the voice user’s self-assessment may be linked to his or her vocal demands at work or in daily life. Sometimes even a mild vocal problem may cause avoidance of voice activities and experience of one’s serious vocal problem, eg for a singer or singing teacher, whose vocal demands may be extremely high. Sometimes even early minor symptoms of vocal fatigue may be registered by an attentive professional voice user as AL or PR, although laryngeal changes cannot yet be detected. In contrast, remarkable organic changes may be ignored by a voice user, if it does not have marked negative vocal consequences, eg deterioration of voice quality, audibility, or endurance. Yiu24 suggests that the impact of voice problems on an individual depends on how the individual perceives, responds, and adapts to the problem, and not merely on the severity of the disorder. This may not always be in line with the clinical-instrumental evaluation of laryngeal status. In this study, the vocal symptoms, AL, and PR were all selfreported. More studies with comprehensive methods are needed to find out how vocal symptoms, AL, and PR actually affect teachers’ performance and pupils’ learning in classroom situations. CONCLUSIONS Teachers with frequent vocal symptoms, especially those with vocal symptoms recurring weekly, have increased odds ratio for vocal activity limitation and vocal participation restrictions. In addition, the number of symptoms recurring weekly increases these odds in correspondence to the number of symptoms reported. High scores or frequent occurrence of self-reported vocal fatigue symptoms must be taken seriously in the evaluation of vocal working ability. More studies and effective educational and ergonomic interventions for teachers with frequent vocal symptoms are warranted. Acknowledgments This study has been supported by the Finnish Work Environment Fund (Grant No. 103309) and by the Academy of Finland (Grant No. 1128095). REFERENCES 1. Sala E, Laine A, Simberg S, et al. The prevalence of voice disorders among day care center teachers compared with nurses: a questionnaire and clinical study. J Voice. 2001;15:413–423.
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2. Simberg S, Sala E, Vehmas K, et al. Changes in the prevalence of vocal symptoms among teachers during a twelve-year period. J Voice. 2005;19:95– 102. 3. Roy N, Merril RM, Thibeault S, et al. Voice disorders in teachers and the general population: effects on work performance, attendance, and future career choices. J Speech Lang Hear Res. 2004;47:542–551. 4. Epstein R, Remacle A, Morsomme D. From reactive intervention to proactive prevention: the evolution of occupational dysphonia. Perspectives on Voice and Voice Disorders. 2011;21:48–55. 5. Titze IR, Lemke J, Montequin D. Populations in the U.S. workforce who rely on voice as a primary tool of trade: a preliminary report. J Voice. 1997; 11:254–259. 6. Verdolini K, Ramig L. Review: occupational risks for voice problems. Logop Phon Vocol. 2001;26:37–46. 7. Laukkanen A-M, Ilomäki I, Leppänen K, et al. Acoustic measures and self-reports of vocal fatigue by female teachers. J Voice. 2008;22:283–289. 8. Morton V, Watson DR. The impact of impaired vocal quality on children’s ability to process spoken language. Logop Phon Vocol. 2001;26:17–25. 9. Rogerson J, Dodd B. Is there an effect of dysphonic teachers’ voices on children’s processing of spoken language? J Voice. 2005;19:47–60. 10. Lyberg-Åhlander V, Haake M, Brännström J, et al. Does the speaker’s voice quality influence children’s performance on a language comprehension test? Int J Speech Lang Pathol. 2015;17:63–73. 11. Imhof M, Välikoski T-R, Laukkanen A-M, et al. Cognition and interpersonal communication: the effect of voice quality on information processing and person perception. Stud Comm Sci. 2014;14:37–44. 12. World Health Organization. ICIDH-2 International classification of impairment, disability and handicap-Beta-1: A manual of dimensions of disablement and participation. Geneva, Switzerland: Author; 1997. 13. Ma EP, Yiu EM. Voice Activity and Participation Profile: assessing the impact of voice disorders on daily activities. J Speech Lang Hear Res. 2001;44:511– 524.
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14. Ma EPM, Yiu EML. Voice activity limitation and participation restriction in the teaching profession: the need for preventive voice care. J Med Speech Lang Pathol. 2002;10:51–60. 15. Kleemola L, Helminen M, Rorarius E, et al. Voice Activity and Participation profile in assessing the effects of voice disorders on quality of life: estimation of the validity, reliability and responsiveness of the Finnish version. Folia Phoniatr Logop. 2011;63:113–121. 16. Sukanen O, Sihvo M, Rorarius E, et al. Voice Activity and Participation Profile (VAPP) in assessing the effects of voice disorders on patients’ quality of life: validity and reliability of the Finnish version of VAPP. Logop Phon Vocol. 2007;32:3–8. 17. Smith E, Gray S, Dove H, et al. Frequency and effect of teachers’ voice problems. J Voice. 1997;11:81–87. 18. Rantala L, Vilkman E. Relationship between subjective voice complaints and acoustic parameters in teachers’ voice. J Voice. 1999;13:484–495. 19. Ilomäki I, Leppänen K, Kleemola L, et al. Relationships between self-evaluations of voice and working conditions, background factors, and phoniatric findings in female teachers. Logop Phon Vocol. 2009;34: 20–31. 20. Leppänen K, Ilomäki I, Laukkanen AM. One-year follow-up study of self-evaluated effects of voice massage, voice training, and voice hygiene lecture in female teachers. Logop Phon Vocol. 2010;35:13–18. 21. Kankare E, Geneid A, Laukkanen AM, et al. Subjective evaluation of voice and working conditions and phoniatric examination in kindergarten teachers. Folia Phoniatr Logop. 2012;64:12–19. 22. Sliwinska-Kowalska M, Niebudek-Bogusz E, Fiszer M, et al. The prevalence and risk factors for occupational voice disorders in teachers. Folia Phoniatr Logop. 2006;58:85–101. 23. Sulica L. Laryngoscopy, stroboscopy and other tools for the evaluation of voice disorder. Otolaryngol Clin North Am. 2013;46:21–30. 24. Yiu EML. Impact and prevention of voice problems in the teaching profession: embracing the consumers’ view. J Voice. 2002;16:215–228.
INTRODUCTION High prevalence of symptoms of vocal fatigue and increased risk for voice disorders have been found in teachers.1–4 However, their potential effects on limiting the vocal activity and restricting the vocal participation are still to be investigated. The consequences of voice problems may be vocal, professional, or socioeconomic. Voice problems may lead to limitations in work and social life, absenteeism, and financial loss.5–7 Because voice is the primary tool of instruction in the classroom, it is essential that the pupils can hear and understand the teacher without difficulty. Pupils have shown weaker learning outcomes when listening to a teacher with dysfunctional voice8–10 as impaired vocal quality adds listeners’ processing load and processing time.11 Therefore, it is important to find out how vocal symptoms are associated with teachers’ ability to do their vocal work and to participate in work and daily life. Very frequently occurring vocal symptoms are considered to be a serious condition of vocal fatigue in teachers. Sala et al1 defined two or more self-reported weekly or more often occurring symptoms to be a borderline of significant voice disorder. The present study investigated this and also different numbers of frequent symptoms to find out how they contribute to teachers’ Accepted for publication July 26, 2016. From the *Speech and Voice Research Laboratory, School of Education, University of Tampere, Tampere, Finland; †Department of Otorhinolaryngology and Phoniatrics, Tampere University Hospital and School of Medicine, University of Tampere, Tampere, Finland; and the ‡Department of Otolaryngology and Phoniatrics—Head and Neck Surgery, Helsinki University Hospital and University of Helsinki, Tampere, Finland. Address correspondence and reprint requests to Irma Ilomäki, Speech and Voice Research Laboratory, School of Education, University of Tampere, Tampere 33014 Finland. E-mail: [email protected] Journal of Voice, Vol. 31, No. 2, pp. 248.e7–248.e10 0892-1997 © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.jvoice.2016.07.025
voice-related activity limitation (AL) or participation restriction (PR). AL and PR may deteriorate teachers’ vocal working ability and voice-related quality of life. Additionally, this might indirectly affect pupils’ possibilities of equal learning in those teachers’ classrooms. Based on World Health Organization’s ICIDH-2 International classification of impairment, disability and handicap-Beta1, with concepts “activity limitation” (instead of their previous term “disability”) and “participation restriction” (previously “handicap”) (ICIDH-2 Beta 1, WHO 199712), Ma and Yiu13,14 have developed an assessment tool, which is the Voice Activity and Participation Profile (VAPP), for evaluation of vocal functioning. The VAPP is a self-evaluation questionnaire about the effects of vocal symptoms on occupational and other daily activities and functioning,13 with a validated Finnish version.15,16 It provides information about the impact of voice on the life and working ability of the individual. The VAPP is composed of 28 questions, divided into five sections: self-perception of the vocal problem severity (one question, maximum score of 10) and the effects of voice problems at work (four questions, maximum score of 40), daily communication (12 questions, maximum score of 120), social communication (four questions, maximum score of 40), and expression of emotions (seven questions, maximum score of 70). Besides these, the sum scores of AL and PR are calculated. AL is calculated by the sum of all even questions of sections 2–4 (work, daily communication, and social communication) and PR by the sum of all uneven questions of these three sections. The AL questions consider, eg, voice user’s difficulties to become understood in conversations or heard in noisy situations due to voice problems. PR is assessed, eg, by questions about avoidance of speaking or unwillingness to take part in communication situations because of one’s voice problems. The maximum scores
Irma Ilomäki et al
Vocal Fatigue Symptoms and Laryngeal Status
on both AL and PR are 100; higher score means worse situation in voice use. Ma and Yiu13 define “activity limitation” as constraints imposed on voice activities, and “participation restriction” as reduction or avoidance of voice activities by an individual. The VAPP questionnaire was used in the present study because it presents the attempt to capture the effects of voice problems on occupational activities. Vocal symptom questionnaires have varied in previous studies.1–3,17,18 Most common questions for teachers have concerned, eg, hoarseness, increased effort, difficulty in being heard, voice breaks, aphonia, and feelings of physical discomfort such as feeling of lump or pain in the throat. The number of separate symptoms asked has varied from 6 to 16. For example, Sala et al1 asked about seven symptoms: throat clearing, voice tires easily, hoarseness, sore throat or globus, voice breaks, difficulty in being heard, or aphonia. The 4–6 point prevalence scales have varied from “no symptoms/hardly ever” to “very frequently occurring/weekly/daily” symptoms. In the present study, a symptom questionnaire of eight questions evaluated with 4-point scale (“hardly ever/occasionally/monthly/or weekly”) was developed on the basis of previous studies. The instructions given for filling the questionnaire were to think of a situation where a voice user has used his or her voice for a relatively long time, ie, to report the symptoms that could be the result of voice fatigue. METHODS The participants of the study were 206 female kindergarten and primary school teachers (116 kindergarten teachers, 90 primary school teachers). The mean age of the teachers was 42.4 ± SD 8.9 years, and the mean year in profession was 16.4 ± SD 9.4 years. Other aspects of the data have been reported earlier.19–21 Laryngeal status of the participants was assessed by experienced phoniatricians in schools and kindergartens through indirect laryngoscopy. Organic laryngeal changes showed in 45% of the subjects studied. Obvious organic laryngeal changes, such as vocal fold nodules, polyps, chronic laryngitis, or vocal fold atrophy, were found in 11%. Mild organic changes, such as mild vocal fold or arytenoid edema and mild closure incompetence, were observed in 34%. The rest, 55% of the teachers, were without organic laryngeal changes. The details of assessment of laryngeal status have been documented in earlier studies.19,21 In the self-evaluation questionnaire, the teachers were asked eight questions about the frequency of their possible vocal fatigue symptoms: strainedness, mucus in the throat, irritation in the throat, pain in the throat, hoarseness without infection, voice breaks, aphonia without infection, and vocal fatigue causing troubles in social life after a working day. They were instructed to think of a situation where they have used their voices for a relatively long time. The assessment scale was a 4-point scale with prevalence of symptoms being “hardly ever/ occasionally/monthly/or weekly.” The incidence of vocal symptoms was then scored in five of the questions (strainedness, mucus in the throat, irritation in the throat, pain in the throat, and hoarseness without infection), with scores of 0 “hardly ever,” 2 “occasionally,” 4 “monthly,” and 7 “weekly,” with a subscore of 35 in total. Three of the questions (voice breaks, aphonia without infection, and vocal fatigue causing troubles in social
248.e8
life) were scored using some emphasis on the statements which were considered to illustrate more serious voice problems (0 “hardly ever,” 3 “occasionally,” 5 “monthly,” and 8 “weekly,” with a subscore of 24). The combined total score was 59. The mean vocal symptom score of all teachers was 24.3 (41.2% of maximum score). This average was used to divide the teachers into two subgroups based on their scores of vocal symptoms mentioned before. The subjects with scores more than the mean of the whole group were regarded as cases of the study (group A), whereas the subjects with scores less than the mean were regarded as the control (group B). Accordingly, subgroup A serves as the group with subjects with many complaints, whereas subgroup B is the group with fewer complaints. Such dichotomized method was used to study the AL and PR correlates in addition to the differences between the two groups. In addition, the number of symptoms occurring weekly was also calculated by summing the number of symptoms per week, being one or more (1+), two or more (2+), three or more (3+), or four or more (4+) symptoms occurring weekly. The number of symptoms occurring weekly was studied in correlation with AL or PR derived from the VAPP. Statistical analyses were carried out using the IBM SPSS Statistics 21.0 software for Windows (SPSS Inc., Chicago, IL). Odds ratio (OR, ratio of the probabilities of an event happening to that of it not happening) was calculated with Risk Estimate in Crosstabs and statistical significance of group differences with binary logistic regression. OR was used to determine whether a particular exposure (in this study: higher score or more frequent symptoms) is associated with/is a risk factor for higher AL or PR, and to compare the magnitude of risk factors with that outcome. A significance level of 0.05 (5%) was considered for all the analyses, and all the reliability intervals were based on 95% confidence interval (CI). As to the interpretation of odds results, OR = 1 shows that exposure does not affect odds of outcome, OR > 1 exposure is associated with higher odds of outcome, and OR < 1 exposure is associated with lower odds of outcome. RESULTS The odds for AL and PR in teachers with or without organic laryngeal changes were OR = 1.3 (95% CI: 0.82–1.5) for AL, and OR = 1.1 (95% CI: 0.78–1.4) for PR. These results showed that organic changes are associated with higher odds of AL or PR, but this remained statistically insignificant. Subgroups A and B were compared in terms of AL and PR. Subgroup A, which had higher scores (frequency) of vocal symptoms, showed 3.7 times more likely activity limitation (OR: 3.7, 95% CI: 2.0–6.8, P < .0001) and 2.6 times more likely participation restriction (OR: 2.6, 95% CI: 1.5–4.7, P = 0.0012) than subgroup B. Both results were statistically significant. The number of vocal symptoms recurring weekly and reported by the teachers was studied. Of the 206 teachers, 73 (35%) reported one or more (1+) weekly symptoms, 50 (24%) two or more (2+), 35 (17%) three or more (3+), and 24 (12%) of the teachers reported four or more (4+) weekly symptoms. One hundred thirty-three (65%) of the teachers did not have weekly recurring symptoms. The details of odds for AL based on the
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Journal of Voice, Vol. 31, No. 2, 2017
TABLE 1. Odds for AL among Teachers Based on the Number of Weekly Recurring Vocal Symptoms Number of Weekly Recurring Symptoms
% of 206 Teachers
Odds Ratio for AL
95% CI
P-value
1+ weekly 2+ weekly 3+ weekly 4+ weekly
35 24 17 12
3.5 4.6 5.2 8.5
1.9–6.5 2.2–9.6 2.1–12.7 2.4–29.8
P = 0.0001 P < 0.0001 P = 0.0003 P = 0.0008
All odds ratios were statistically significant. Abbreviations: AL, activity limitation; CI, confidence interval.
TABLE 2. Odds for PR among Teachers Based on the Number of Weekly Recurring Vocal Symptoms Number of Weekly Recurring Symptoms
% of 206 Teachers
Odds Ratio for PR
95% CI
P-value
1+ weekly 2+ weekly 3+ weekly 4+ weekly
35 24 17 12
2.8 4.5 5.1 6.0
1.5–5.1 2.2–9.3 2.1–12.5 2.0–18.2
P = 0.0001 P < 0.0001 P = 0.0003 P = 0.0002
All odds ratios were statistically significant. Abbreviations: PR, participation restriction; CI, confidence interval.
number of weekly recurring vocal symptoms are shown in Table 1 and odds for PR in Table 2. DISCUSSION Higher scores or the number of weekly symptoms of vocal fatigue were associated with increased vocal AL and PR. Subgroup A teachers with higher symptom scores showed increased AL 3.7 times more likely and PR 2.6 times more likely than subgroup B teachers with lower scores. The odds for higher AL and PR also increase with the number of symptoms recurring weekly; these were 2.6–8.5 times more likely in teachers with one, two, three, or four weekly symptoms. Thus, the consequences of the higher number of vocal symptoms or increase in symptoms recurring weekly are clearly associated with limitation of vocal activities and restriction of participation that are based on World Health Organization’s International Classification of Functioning and Disability (ICIDH-2 Beta 1, WHO 1997). A study by Sala et al1 suggested that two or more weekly recurring vocal symptoms, regardless of the symptom, may be a borderline for diagnosis of significant voice disorder. Our results point to the fact that even one symptom recurring weekly increases the odds for limitation in vocal activities and participation. Such finding may indicate the situation of significant voice disorder and might be suspected as a threshold, which is less than the one reported by Sala et al.1
Laryngeal organic changes were quite common. Obvious or mild changes were found among 45% of our studied teachers in comparison to previous studies; for example, SliwinskaKowalska et al22 found voice disorders in 32.9% of the teachers and Sala et al1 in 29%. Odds ratios for AL or PR were higher among the teachers with organic changes but still remain statistically insignificant. It is possible that the teachers with such changes are to a certain extent aware of the problems with their voice and tend to use it in a controlled way21 that does not end in raising the odds significantly for vocal activity limitation and vocal participation restrictions. Sulica23 analyzes the selfevaluation of voice in relation to the clinical evaluation and points out that the voice user’s self-assessment may be linked to his or her vocal demands at work or in daily life. Sometimes even a mild vocal problem may cause avoidance of voice activities and experience of one’s serious vocal problem, eg for a singer or singing teacher, whose vocal demands may be extremely high. Sometimes even early minor symptoms of vocal fatigue may be registered by an attentive professional voice user as AL or PR, although laryngeal changes cannot yet be detected. In contrast, remarkable organic changes may be ignored by a voice user, if it does not have marked negative vocal consequences, eg deterioration of voice quality, audibility, or endurance. Yiu24 suggests that the impact of voice problems on an individual depends on how the individual perceives, responds, and adapts to the problem, and not merely on the severity of the disorder. This may not always be in line with the clinical-instrumental evaluation of laryngeal status. In this study, the vocal symptoms, AL, and PR were all selfreported. More studies with comprehensive methods are needed to find out how vocal symptoms, AL, and PR actually affect teachers’ performance and pupils’ learning in classroom situations. CONCLUSIONS Teachers with frequent vocal symptoms, especially those with vocal symptoms recurring weekly, have increased odds ratio for vocal activity limitation and vocal participation restrictions. In addition, the number of symptoms recurring weekly increases these odds in correspondence to the number of symptoms reported. High scores or frequent occurrence of self-reported vocal fatigue symptoms must be taken seriously in the evaluation of vocal working ability. More studies and effective educational and ergonomic interventions for teachers with frequent vocal symptoms are warranted. Acknowledgments This study has been supported by the Finnish Work Environment Fund (Grant No. 103309) and by the Academy of Finland (Grant No. 1128095). REFERENCES 1. Sala E, Laine A, Simberg S, et al. The prevalence of voice disorders among day care center teachers compared with nurses: a questionnaire and clinical study. J Voice. 2001;15:413–423.
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