Contribution
Validation of Sound Absorption Coefficients for Tyre-Road Noise Prediction
* Presenting author
Abstract:
The TyreRoadNoise project was launched to deepen our understanding of the parameters influencing tyre-road noise and to develop a robust prediction model using physical, data-driven, and hybrid approaches. An important model parameter in characterizing road surfaces is the sound absorption coefficient. Various methods exist for measuring sound absorption: In laboratory settings, material samples are typically measured using an impedance tube following (EN) ISO 10534-2 standards. However, in-situ measurements are often preferred to evaluate actual surface conditions. For noise barriers, EN 1793-5 outlines the method for determining sound absorption via the reflection index, whereas for road surfaces, the extended surface method and the spot method, as per ISO 13472-1 and -2 respectively, are commonly applied. This contribution addresses two key questions: (1) How comparable are the sound absorption coefficients obtained from different measurement techniques? and (2) How can lab-based measurements of material samples be correlated with in-situ results? Both theoretical and experimental analyses will be conducted to address these questions, eventually assessing the validity and reliability of sound absorption measurements across various methods.