posted by sandhu .
1.A wall between two rooms is 20 x 9 ft. The wall construction has Transmission Loss 50 dB at 1000 Hz. In the wall is a small window of size 4 x 2 ft. The window has a tested Transmission Loss of 20 dB at the same frequency. The receiving room has 200 ft^2 Sabine absorption. What is the Noise Reduction NR of the wall without the window?
2.Two identical offices are separated by a wall 15 x 8 ft. Sabine absorption in the offices is 150 ft2 . In one office the Sound Intensity Level is 72 dB. What transmission loss is required for the common wall if the SIL in the second office is to be 35 dB?