ABSTRACT
The evaluation of acoustic conditions in four high schools showed that acoustic climate in high schools is more favourable than in elementary schools. During breaks the noise in corridors is about 77 dB (about 9 dB lower than in elementary schools). During lessons these differences are lower. In comparison to the elementary schools the noise level both in the corridors and in the classrooms is about 5 dB lower (60 i 62 dB respectively). During lessons the noise level depends mainly on number of pupils, manner of teaching, a type of task performed by schoolchildren and the day of the week. The work in groups is noisiest (average more 5 - 7 dB than during lectures). The more favourable acoustic conditions are in classes below 25 pupils but in classes above 30 pupils the noise level during lessons increases about 3dB. The noise in classroom depends also on period of duration of the lesson and the day of the week. However it was not observed significant differences in daily distribution of the noise level, subject of the lesson or year of schooling. Resultant daily noise exposure of schoolchildren in high schools during their school time is 73 dB and is about 7 dB lower than in elementary schools.