PENENTUAN PENGURANGAN KEBISINGAN OLEH KARPET PADA RUANG TERTUTUP

It has been done a test of noise reduction using carpet by variating its thichness and its distance to noise source in a room (glass box). The thichnes of carpet was 0,246 cm, 0,492 cm and 0,738 cm. The noise reduction was measured at three different position of 30 cm, 50 cm and 70 cm from the noise source. The frequency of noise source used was 125, 250, 500, 1000, 2000, 4000 Hz. The measurement was performed at 95 cm to the nosie source by using sound level meter (SLM) SL 4112. The result showed that for a same thichness and variated measurement distance, the value of noise reduction was independent to the frequency. Noise reduction was getting smaller as increasing the thickness of the carpet. It’s value was maximum at the frequency of 2000 Hz and minimum at the frequency of 500 - 1000 Hz. The relation noise reduction to with frequency yielded a certain pattern, which was the larger carpet thichness the higher the nosie reduction would be. The lowest noise reduction was found at frequency of 500 - 1000 Hz, and the maximum noise reduction was accured at 2000 Hz.