Test apparatus and test method for impedance characteristic and capacity expansion performance of sound absorbing material

摘要

To provide a technical index for selecting a sound absorbing material and to reduce the manufacturing cost of an acoustic product.A closed cavity formed by communicating a first cavity (10) and a second cavity (20) in which a sound absorbing material (40) is placed via one slit passageway, a sealed cavity used for providing test sound pressure, An acoustic excitation source 50 whose sound surface is located in the first cavity 10 and a pickup surface are provided in the first cavity 10 and the second cavity 20, respectively, and the first cavity 10 and the second cavity 10 And two pickup sensors 60, 62 for detecting the sound pressure in the cavity 20 of the first cavity 10 and the second cavity 20, and both materials surrounding the first cavity 10 and the second cavity 20 are sound insulation materials.BACKGROUND OF THE INVENTION