An increase in fundamental frequency (F₀) and in sound pressure level (SPL) has been reported both after vocal loading tests and after a teacher’s working day. This increase has been found to be greater among teachers with fewer voice complaints. The present study investigated speech changes during a teacher’s working day (a) in ordinary conditions and (b) when using electric sound amplification while teaching. Five Icelandic teachers (mean age 51 years) volunteered as subjects. Classroom speech was recorded with a portable DAT recorder and a head-mounted microphone first in ordinary conditions, and the next week while using electrical sound amplification. Recordings were made during the first and the last lesson of the hardest working day of the week. F₀ and SPL were analyzed. The subjects’ comments were gathered by questionnaire. An increase in F₀ and SPL was found during the working day in both teaching conditions but the change was larger and for F₀ statistically significant when amplification was used. All 5 teachers reported less tiredness of the vocal mechanism when using amplification. The results support the suggestion that a vocal loading-related increase in F₀ and SPL is not merely a sign of vocal fatigue but may even reflect an adequate adaptation to loading. Situational factors cannot be ignored, however.

The present study investigated changes in the voice quality of teachers during a working day (a) in ordinary conditions and (b) when using electrical sound amplification while teaching. Classroom speech of 5 teachers was recorded with a portable DAT recorder and a head-mounted microphone during the first and the last lesson of a hard working day first in ordinary conditions and the following week using amplification. Long-term average spectrum and sound pressure level (SPL) analyses were made. The subjects’ comments were gathered by questionnaire. Voice quality was evaluated by 2 speech trainers. With amplification, SPL was lower and the spectrum more tilted. Voice quality was evaluated to be better. The subjects reported less fatigue in the vocal mechanism. Spectral tilt decreased and SPL increased during the day. There was a tendency for perceived asthenia to decrease. No significant changes were observed in ordinary conditions. The acoustic changes seem to reflect a positive adaptation to vocal loading. Their absence may be a sign of vocal fatigue.

This study investigated one possible method to diminish teachers' vocal loading and, consequently, voice problems. Thirty-three teachers used electric sound amplification in teaching for at least 1 week. Both the teachers (33) and the students (791) reported their opinions of the amplification in a questionnaire. Ninety-seven percent of the teachers reported easier voice production, 82% found improved vocal endurance. The need for repetition also diminished. Eighty-four percent of the students found listening easier and 63% concentration better when amplification was used. The negative points reported both by teachers and students were technical problems (e.g. incorrect sound level or placement of the amplifier). Electrical amplification, thus, can be recommended in classroom use provided that the technical problems have been solved.

Research suggests that teaching activities involve a high risk of developing voice disorders. The aim of this study is to examine the possible difference in the occurrence and nature of vocal symptoms in two groups of teachers-head teachers (N = 43), including both principals and assistant head teachers, and teachers of physical education (N = 43)--and to investigate the possible role of gender. The questionnaire results indicate that demands on the voice for P.E. teachers and head teachers are different. The findings suggest that (i) demands influence the occurrence and nature of reported vocal symptoms, (ii) that teachers of physical education are at a greater risk of developing voice problems, and (iii) that female P.E. teachers are at particular risk.

Voice problems are common among teachers. This is most likely due to the heavy vocal load of their profession. The present study investigated one possible method to decrease the vocal load. The effects of amplification on classroom speech were studied on five Icelandic teachers (three females, two males, mean age 51 years). Classroom speech was recorded with a portable DAT recorder and a head-mounted microphone, first under ordinary conditions and in the next week while using electrical sound amplification. The average fundamental frequency (F0), sound pressure level (SPL) and phonation time were measured. According to the results, amplification significantly lowered both F0 (average 8.6 Hz for the females and 11.3 Hz for the males, p = 0.002 and 0.0001, respectively) and SPL (about 1 dB for both genders, p < 0.05), while phonation time was not significantly affected. The results suggest that electric amplification is likely to reduce vocal load.