Noise pollution is a very serious problem that prevents learning in the school environment and affects human health physiologically and psychologically. The purpose of this study is to assess the noise level, with causes and effects, in a school that has been acoustically improved. The research was conducted in a middle school where acoustic improvement was made in the Antalya province center. To collect data, a sound level meter was used, a questionnaire was administered and interviews were conducted. Noise and resonance measurements were made with the Bruel & Kjaer 2250-A-D00 handheld analyzer in acoustically improved and non-acoustical classrooms. The questionnaire, answered by 19 teachers, was analyzed using SPSS. Interviews were conducted with the school principal and a teacher. Noise measurements reveal that both the noise level and the reverberation levels are lower than typical with acoustic improvements. According to the survey results, approximately 70% of the teachers think that the noise level of the school is generally low and moderate. As a result of acoustical improvements,, a teacher said his headache was gone, while the school principal said that his hearing and the intelligibility of speech increased. On the other hand, more than half of the teachers stated that the noise level was still too high during the break time. The results suggest that all schools should be required to measure noise and reverberation levels and provide noise awareness training to all their stakeholders.