Two-Microphone Impedance Tube Method를 이용한 차음재의 음향투과손실 측정

A new two-microphone impedance tube method to practically measure the sound transmission loss of sound isolation materials having small flexural rigidity has been proposed and validated in the previous research[4]. In this study, the influences of the size and the physical property of several sound isolation materials on the measured sound transmission loss are discussed. From the experimental results, it is found that the two-microphone impedance tube method is no longer valid to measure the sound transmission loss of sound isolation materials having large flexural rigidity because the regions of resonance and mass law are moved into the ranges in high frequency. In addition, in order to accurately measure the sound transmission loss of sound isolation materials, their size should be decided based on the consideration of the effect of acoustic excitation on their vibration response.