Contribution
Experimental in situ estimation of the acoustic boundary impedance
* Presenting author
Abstract:
Accurate interior acoustic simulations require precise knowledge of the boundary properties of all interacting surfaces. Typically, the boundary impedance, which fully characterizes the acoustic properties of a surface, is determined under laboratory conditions such as the impedance tube. However, this method has limitations, as it does not account for real-world mounting conditions, motivating the need for in situ characterization techniques. In this study, measurements were taken at a limited number of measurement points near the walls of a vocal practice room. A simulation-based inference approach is used to determine the boundary impedance in situ, where a neural network is trained to approximate the posterior probability distributions of the unknown impedances. The core of this approach is a finite element model, which serves as the forward model during inference. This makes the approach particularly well-suited for applications with pre-existing models, such as digital twin applications or model updating.