Which teachers are most at risk for voice disorders? Individual factors predicting vocal acoustic parameters monitored in situ during a workweek.

PURPOSE

To identify the factors affecting teachers' vocal acoustic parameters, with the aim of detecting individuals at risk of phonotrauma.

METHOD

The voicing time, voice sound pressure level [SPL] and fundamental frequency [f] of 87 teachers were measured during one workweek using a voice dosimeter. We retrospectively investigated the impact of 10 factors (gender, age, teaching experience, teaching level, tobacco, gastro-esophageal problems, nonoccupational voice activity, voice education, past voice problems, and biopsychosocial impact of voice problems measured using the Voice Handicap Index [VHI]) on each voice parameter.

RESULTS

None of the above factors affected voicing time or SPL. f depended significantly on gender, teaching level, nonoccupational voice activity and VHI score. Specifically, f was higher in women (Δ = 69 Hz), in individuals without nonoccupational voice activities (Δ = 11 Hz), and in individuals with a lower VHI score (increase of 0.7 Hz for each additional point). For females, post hoc comparisons revealed a substantial impact of teaching level on f: university instructors had deeper voices than kindergarten (Δ = 66 Hz), elementary (Δ = 52 Hz), or secondary teachers (Δ = 41 Hz).

CONCLUSIONS

Since higher f increases the mechanical stress related to vocal fold vibration, the screening and prevention of phonotrauma should focus primarily on women, particularly those who teach at lower levels, and teachers with more self-rated voice problems. The lower f of teachers who engage in nonprofessional voice activities may suggest acute inflammation or muscle fatigue due to voice overload.