Introduction & Objective: Noise is one of the most important harmful agents in work environment. In spit of industrial improvements, exposure with over permissible limit of noise is counted as one of the health complication of workers. In Iran, do not exact information of the absorption coefficient of acoustic materials. Iranian manufacturer have not laboratory for measured of sound absorbanc...

Introduction: Noise pollution cause mental fatigue, concentration disturbance and learning loss in students during the training activities. This study aims to evaluate Noise pollution and the level of acoustical comfort in typical classrooms, and present treatment methods for improving acoustic comfort. Method: In cross sectional study, twenty classrooms in the seven faculty of Hamadan Univers...