Effects of curtain treatment on reverberation time of a classroom

Abstract

We report findings of how the reverberation time (RT) of an unfurnished, unoccupied classroom is affected by treating the walls with curtain. A Brüel and Kjær sound analyzer was used for the measurement of RT. With the treated surface area A_t (area of the wall covered by curtains) of the room kept constant, a non linear trend in the decrease of RT was observed while increasing the area of the curtain A_c (curtain's total undraped surface). Results revealed that there is a certain maximum value of A_c (for a given A_t) at which the treatment is still very effective. Greater than such value does not result to a further decrease in RT. Furthermore, the effect of varying A_t for a given A_c showed a significant decrease in RT at larger A_t.