In the automotive industry, sound-absorbing materials are used to control vehicle noise and improve the quality of the acoustic environment of a vehicle cabin. With the recent development of the automotive industry, engineers, designers, or material manufacturers are required to design vehicle interior systems that are suitable for new types of vehicles such as renewable energy vehicles or autonomous vehicles in a fast and inexpensive way. However, the existing methods have some disadvantages in evaluating the acoustic performance of sound-absorbing materials. The impedance tube can not measure 3D systems and the full-size reverberation room is enormous and costly. To address this issue, this paper presents a self-made reduced-size reverberation room, which is only 2.588 m3, and explores its measurement capabilities. The measured random incidence sound absorption coefficient (SAC) from the small-size reverberation room was compared to the results from a full-size reverberation room for ten different commercial samples. It is shown that the SAC measured in the small-size reverberation room is in reasonable agreement with the SAC measured in the full-size reverberation room in the frequency range above 400 Hz. This small-scale reverberation room can enable engineers, designers, or material manufacturers to conduct acoustic experiments in an efficient way at an early stage of the interior trim and accessories development design process, which can reduce overall development costs.

RMIT University: Yujun Zhao, Jinhui Xu, Mohammad Fard; Infrastructure Technologies, CSIRO: John Laurence Davy, John Watson