Research of acoustic parameters characterizing the room for verbal communication in terms of improvement of working conditions at workplaces.

The aim of the project was to develop tools for monitoring acoustic parameters specifying the status of working conditions in the rooms which the precise use is verbal communication. Since most of the rooms of this type are classrooms research completed with a focus on these rooms. It was assumed that if the acoustics of the classroom could be considered appropriate for verbal communication , a room reverberation time for frequencies of 125 and 400 Hz should be in the ranges: -from 0.35 to 0.65 s,while speech transmission index STI should be equal to or greater than 0.62 (in the classrooms for teaching younger children and teaching foreign languages, speech transmission index (STI).is proposed to be equal to or greater than 0.7). Based on surveys conducted in 100 primary schools in Warsaw selected 5 schools, in which in 88 classrooms (none of the rooms was adapted acoustically)performed the initial parameters by a simplified preliminary measurements. It has been found that only one room meets the requirements. Developed two new parameters similar in character to the reverberation time and speech transmission index STI determined by computational methods, and developed methods for measure these parameters. These parameters can be used to estimate the acoustic conditions in the newly designed rooms. Also performed the impact studies of acoustic adaptation to reduce the level of the teacher`s voice.