Round robin study of a reference sample for PU in-situ sound absorption characterization

The determination of acoustic material properties plays a fundamental role in simulating and designing effective noise reduction treatments. Several standardized measurement techniques are available for characterizing sound absorption, such as Kundt’s tube and reverberant room methods. Yet, most traditional methods cannot be used in-situ and require undesirable experimental constraints. The PU in-situ method can be used in a broad frequency range while hardly being affected by background noise and reflections. Furthermore, the PU in-situ approach is suitable for testing complex materials in their target environments, without deforming or changing their mounting conditions. However, the absence of a controlled environment may introduce a significant bias in the experimental sound absorption estimation. A reference sample is hereby studied to have a better understanding of how different experimental factors affect the sound absorption estimation quality. A round robin study was conducted using a reference porous material in different measurement environments, with various measuring systems and several samples. With statistical analysis on the measurement data, a confidence interval of the sound absorption was extracted. This investigation provides a qualitative evaluation of the entire measuring system and environment to ensure the reliability of the PU in-situ sound absorption setup.