Voice Problems in Teachers: Prevalence, Risk Factors, and Vocal Loading

Abstract

Aims: This research determined: a) prevalence of voice problems in New Zealand teachers; b) factors associated with voice problems and voice related quality of life in teachers; c) whether there are differences in vocal load and environmental noise levels and acoustic parameters of classrooms between primary and secondary teachers with and without selfreported voice problems; d) changes in voice use over the teaching day; and e) correlations between vocal load, voice self-assessment, and environmental measures. Methods: The first two studies were cross-sectional online surveys. In study 1, participants were 1879 primary and secondary teachers (72.5% females). Three time-frames were used to determine prevalence of self-reported voice problems (day of survey, previous teaching year, career). Severity of voice problems, recovery time, days away from work, symptoms, health assistance, and voice education were also investigated. Study 2 used multivariate analyses to identify factors associated with voice-related quality of life and voice problems in 572 teachers (74% females). A range of potential antecedent factors including demographic, teaching related, voice related, environmental, psychosocial, health, and lifestyle factors were explored. Regression models were determined for frequency and severity of voice problems, V-RQOL scores, voice symptoms, and voice quality. Study 3 used vocal and noise dosimetry over two teaching days in 16 teachers with voice problems and 14 controls. Results: Study 1: Prevalence of self-reported vocal problems was 33.2% over teaching careers, 24.7% over the year, and 13.2% on the day of the survey. Voice problems were more prevalent in primary teachers (p<.001; OR=1.74; CI=1.33-2.40), females (p=.008; OR=1.63; CI=1.13-2.37), and those aged 51-60 years (p=0.010; OR=1.45; CI=1.11-3.00). Among teachers reporting voice problems during the year, 47% were moderate/severe and 30% took more than 1 week to recover. Approximately 28% of teachers stayed away from work 1-3 days due to a vocal problem and 9% stayed away > 3 days. Symptoms associated with voice problems (p<.001) were voice quality alteration (OR=4.35; CI=3.40-5.57), vocal effort (OR=1.15; CI=0.96-1.37), voice breaks (OR=1.55; CI=1.30-1.84), projection difficulty (OR=1.25; CI=1.04-1.50), and throat discomfort (OR=1.22; CI=1.02-1.47). Only 22.5% with voice problems consulted health practitioners. More voice training/education was associated with fewer voice problems. Study 2: Multivariate analyses revealed associations between teaching demographics, voice use, environmental and psychosocial factors, health and voice problems and voice-related quality of life; significant factors included harmful voice use, reflux symptoms, classroom noise, stress, lower hours of voice education/training and voice rest, upper respiratory tract infections, exposure to chemicals, extraversion, self-efficacy, job satisfaction, openness to experience, agreeableness, and avoidance coping behavior. Study 3: The voice problem group had higher phonation time, and spoke more quietly than controls. Peak classroom noise levels were greater for controls. All teachers showed increased F0, decreased phonation time, and decreased LAeq median noise levels over the day and positive correlations between F0 and voice SPL, environmental noise levels and voice SPL. Several vocal load parameters correlated with voice self-ratings. Conclusions: Voice problems are prevalent for teachers in New Zealand, as is the case in other countries. Teachers with voice problems spoke for longer periods and more quietly, and had more frequent and more severe symptoms than teachers without voice problems. There is limited awareness among teachers about vocal health, potential risks, and health services for voice problems. This research highlighted the need for voice education and training programmes and provides evidence for their development through identification of vocal behaviors and other voice risk factors for teachers.