The design of an impedance tube and testing of sound absorption coefficient of selected materials

Abstract

Abstract The paper describes a design, building and testing a low-cost impedance tube for measuring the acoustic parameters of small testing samples. The measurement of sound absorption coefficient is based on transfer function and the two microphone method in accordance with ISO 10534-2 and ASTM E 1050 standards. With small configuration updates and after installation of additional microphones on measuring apparatus testing of complex acoustic material properties can be performed. The impedance tube has been used also as a teaching tool.