T/JAMIA 003-2023 Active

Scope: This document specifies the method for measuring the sound absorption coefficient of samples with irregular shapes and complex geometries, or the sound absorption volume of spatial sound-absorbing bodies such as furniture, people, and automotive parts in a small reverberation chamber. This document is applicable to measuring the sound absorption coefficient of acoustic loads, allowing for timely feedback and optimization of products. Main technical content: The sound absorption coefficient of materials is an important indicator of material acoustic performance, which plays a guiding role in analyzing the application of materials in industrial production and daily life. Common methods for measuring the sound absorption coefficient of materials include the reverberation chamber method and the standing wave tube method. The reverberation chamber method is used to measure the sound absorption coefficient when sound is incident irregularly, while the standing wave tube method is used to measure the sound absorption coefficient when sound is incident directly (with an incident angle of 90°). Since most sounds in engineering and architectural applications are irregularly incident, the reverberation chamber method is commonly used to measure the sound absorption coefficient of materials in actual engineering. However, the samples to be measured are often small irregular specimens, which do not meet the standard specimen size required for measurement by the standard reverberation chamber method. The small reverberation chamber is a professional experimental device in the field of acoustic measurement, with relatively uniform sound energy density in the chamber, forming a diffuse sound field, and is mainly used for measuring the sound absorption characteristics of small irregular components (such as automotive components). Compared with the standard reverberation chamber, it has the advantages of low cost, small floor area, and easy mobility. Based on these advantages,