Study on Acoustic Transmission Loss in 4-channel Impedance Tube with Single-sensor

The principle of 4-channel impedance tube with single-sensor for testing transmission loss(TL) of acoustic materials is introduced,the math-formulas for calculating is also introduced.The influence to the results of different absorbent endings is studied and the best absorbent ending is determined.On this basis,the acoustic transmission losses of PVC polymer and laminated composite materials are tested.The results show that this method can ascertain the accurate transmission loss of small samples with normal incidence.