In this study, music teachers' exposure to sound was tested by measuring the A-weighted equivalent sound pressure level (SPL), the A-weighted maximum SPL and the C-weighted peak SPL. Measurements were taken prior to and after acoustic treatment in four rooms during classes of trumpet, saxophone, French horn, trombone and percussion instruments. Results showed that acoustic treatment affects the exposure of music teachers to sound. Daily noise exposure levels (LEX, 8 h) for all teachers exceeded a limit of 85 dB while teaching music lessons prior to room treatment. It was found that the LEX, 8 h values ranged from 85.8 to 91.6 dB. The highest A-weighted maximum SPL and C-weighted peak SPL that music teachers were exposed to were observed with percussion instruments (LAmax = 110.4 dB and LCpeak = 138.0 dB). After the treatments, daily noise exposure level decreased by an average of 5.8, 3.2, 3.0, 4.2 and 4.5 dB, respectively, for the classes of trumpet, saxophone, French horn, trombone and drums, and did not exceed 85 dB in any case.

The results of long-term continuous noise measurements in two selected schools are presented in the paper. Noise characteristics were measured continuously there for approximately 16 months. Measurements started eight months prior to the acoustic treatment of the school corridors of both schools. An evaluation of the acoustic climates in both schools, before and after the acoustic treatment, was performed based on comparison of these two periods of continuous measurements. The autonomous noise monitoring stations, engineered at the Multimedia Systems Department of the Gdańsk University of Technology were used for this purpose. Investigations of measured noise, especially its influence on hearing sense, assessed on ground of spectral analyses in critical bands, is discussed. Effects of occupational noise exposure, including the Temporary Threshold Shift simulation, are determined. The correlation of the above said measurement results with respective instantaneous noise levels is discussed, and concluding remarks are presented. Some additional indicators such as air pollution or video analysis aiming at the analysis of corridor occupancy are also measured. It should be remembered that excessive noise, or air pollution may be evidence of a dangerous event and may pose health risks.

The paper presents the latest research results concerning the correlation between changes in the room acoustics of school spaces and noticeable changes in the communication and functioning of students and teachers at school.

The primary school covered by the research is the second largest school of this type in Poland. The large number of students and hard interior finishing made the acoustic conditions in the school building very unfavourable. The measurements showed that school rooms were very noisy and reverberant. The measured values of reverberation time T were in many rooms 3–4 times higher than the acceptable values specified in the mandatory Polish acoustic standard PN-B-02151-4:2015-06. Also the speech intelligibility measured by the speech transmission index was very poor, in the extreme case STI = 0:31. This situation (very characteristic for most of Polish schools) became the basis for the first such comprehensive acoustic treatment of the whole school building in Poland. This intervention allowed to meet PN-B-02151-4:2015-06 demands almost in every room accessible for students. This case gave an excellent opportunity to assess the influence of improved room acoustics on teachers’ and students’ performance and wellbeing.

Measurements of the equivalent sound level LAeq, reverberation time T and STI speech transmission index were made before and after acoustic treatment. The questionnaire survey used the Acoustic Change Feelings Scale (ACFS-S, ACFS-T) for teachers and students. 378 students, and 44 teachers were included in the study. Both students’ and teachers’ answers show significant improvement of their performance and wellbeing. Positive changes were noticed in students’ level of concentration, short memory capacity and pace of work. After acoustic treatment students (both in teachers’ and their own opinion) can better hear and understand teachers’ instructions and are much more capable of task fulfilling. Both teachers and students observed clear reduction of aggression level. Teachers reported considerable drop in students’ fatigue and their own voice effort.