Four-microphone Method of Sound Transmission in the Standing Wave Tube

A new method, fourmicrophone method that is used to measure sound transmission loss in the standing wave tube, has been studied in this paper. The method separated the transmission wave from the reflected wave in the absorbent ending. We conducted the formula and made an experiment on the wave tube. The results turn out:that the new method can raise the precision of the measurement, especially in the low frequency range.