Impact of the use of curtains on the spatial distribution of early decay time in Brazilian classrooms

A single value of acoustic descriptors is generally adopted for the entire classroom, in order to characterize the acoustic conditions of this environment. In existing Brazilian schools, the use of curtains is a low cost mechanism generally used for solar protection, but their use could correct reverberation values by bringing these parameters to acceptable ranges. The present research focused on the spatial distribution of the parameter early decay time in classrooms with open and closed curtains. The tool used to estimate the sound behaviour was computational simulation. The classroom models were adjusted using early decay times measured in the simulated rooms. For the classrooms, it was studied the configurations of closed windows and open curtains; and closed windows and closed curtains. The use of curtains does not improve significantly the homogeneity of the early decay time distribution in this environment. Although its use has decreased the values of early decay time, for stricter criteria, they do not reach the recommended values.