Evaluation of the acoustic quality of the environment in a sound insulated school: A case study

In the last half century, the public and acoustic scientists' interest in sound and noise in educational buildings has been increasing. The negative conditions created by noise in learning environments affect a wide part of the society, especially students and teachers. For this reason, pedagogues, psychologists, acoustic consultants, educational institutions as well as insurance institutions are among those who are closely interested in the acoustic conditions of schools. Noise negatively affects the performance of students and teachers at school by masking speech and reducing intelligibility. In addition, noise negatively affects students and teachers in terms of auditory, mental and physical aspects, causing fatigue more quickly and a decrease in interest in the lesson. As a result, it emerges as an important factor that disrupts the school's climate. Research done reveals that students and teachers are heavily exposed to noise pollution at school. Intense noise exposure at school reveals that students' reading, reading comprehension, cognitive processing skills, attention span and transfer of information to long-term memory negatively affect. The acoustic environment of schools should be an environment where students can communicate comfortably and hear their teachers. Unfortunately, noise and acoustics in educational buildings in our country have not been a ix comfort parameter taken into consideration during the design phase. In this study, the sound level of a soundproofed school was tried to be evaluated based on the reverberation time, the opinions of the stakeholders in the school about the auditory comfort of the school, and the observations of the researcher. This research will be carried out within the framework of the holistic single case study design, which is one of the case study designs. Observation data will be supplemented by sound and reverberation measurements. In the study, a study group of six people consisting of four teachers, a principal and a deputy principal was determined. While determining the study group, typical case sample was chosen from qualitative research samples. In the data collection process of the research, semistructured observation and interview forms were used by the researcher. In order to reveal the views of the participants, the interviews were transcribed and analyzed thematically. As a result of the analysis of the research data, the background noise level, one of the acoustic comfort parameters, was found in the range of 33-36 dB(A). These findings are below the regulation limit value of 39 dB(A). The noise level measured while the school is being used actively by students, teachers, administrators and other personnel was measured in the range of 34-55 dB(A). These values measured while the building is in use are quite low noise levels when compared to the studies in the literature. The reverberation time was measured as 0.9 seconds in classrooms, 1.55 seconds in corridors, and 0.7 seconds in dining halls. These measured values are very close to the limit values of the regulation. From these results, it is seen that the selected school has the quality to set a good example in terms of acoustic comfort. In the interviews, it is understood that the administrators and teachers are very satisfied with the auditory comfort of the school. Comparing with the schools they have worked at before, one teacher described the acoustic environment of the school as x "unprecedented". The observations made by the researcher at the school are that there is a general atmosphere of calmness and calmness in the school. When entering the school building from the outside, a serious decrease is felt in the sound pressure level. It has been determined that no bells are used between lessons, and instead, soothing music is played in the background that does not negatively affect communication. In the observations made, it was seen that the entire school was covered with acoustic panels on the suspended ceiling and the floors were furnished with linoleum. From the observation and interview data, it was concluded that the auditory comfort of the school positively affects the sense of belonging to the school and the motivation of the teachers and administrators to work. Keywords: Auditory comfort, school acoustics, noise at school, learning environment, reverberation