Teachers' voice use in teaching environments: a field study using ambulatory phonation monitor.

OBJECTIVES This case-control designed field study examines the vocal behavior in teachers with self-estimated voice problems (VP) and their age- and school-matched voice healthy (VH) colleagues. It was hypothesized that teachers with and teachers without VP use their voices differently regarding fundamental frequency, sound pressure level (SPL), and in relation to the background noise. METHODS Teachers with self-estimated VP (n = 14; two males and 12 females) were age and gender matched to VH school colleagues (n = 14; two males and 12 females). The subjects, recruited from an earlier study, had been examined in laryngeal, vocal, hearing, and psychosocial aspects. The fundamental frequency, SPL, and phonation time were recorded with an Ambulatory Phonation Monitor during one representative workday. The teachers reported their activities in a structured diary. The SPL (including teachers' and students' activity and ambient noise) was recorded with a sound level meter; the room temperature and air quality were measured simultaneously. The acoustic properties of the empty classrooms were measured. RESULTS Teachers with VP behaved vocally different from their VH peers, in particular during teaching sessions. The phonation time was significantly higher in the group with VP, and the number of vibratory cycles differed between the female teachers. The F0 pattern, related to the vocal SPL and room acoustics, differed between the groups. CONCLUSION The results suggest a different vocal behavior in subjects with subjective VP and a higher vocal load with fewer possibilities for vocal recovery.