Measured values of acoustic absorption obtained from standard reverberation chamber measurements often differ from theoretical random incidence absorption coefficients. These discrepancies mostly arise due to non-isotropic sound incidence on the absorbing specimen and diffraction at the sample edges. This study examines an experimental method for characterizing the distribution of sound incidence on the specimen under test conditions. The methodology relies on estimating the wavenumber spectrum to determine the magnitude of the sound waves arriving from definite directions onto the absorbing plane. The method is examined experimentally, based on measurements with a programmable robotic arm in a reverberant room in two damping conditions. The corresponding spatial distribution of the active sound intensity field can also be inferred, making it possible to benchmark the proposed methodology with observations of the incident energy flows.
|Title of host publication||Euronoise 2018 - Conference Proceedings|
|Publisher||European Acoustics Association|
|Publication status||Published - 2018|
|Event||Euronoise 2018 - Convention Center Creta Maris, Hersonissos, Crete, Greece|
Duration: 27 May 2018 → 31 May 2018
|Location||Convention Center Creta Maris|
|Period||27/05/2018 → 31/05/2018|
Nolan, M., Verburg, S. A., Jeong, C-H., Brunskog, J., & Fernandez Grande, E. (2018). A wavenumber approach to quantifying nonuniform sound incidence in measurements of sound absorption in the reverberation chamber. In Euronoise 2018 - Conference Proceedings (pp. 2031-2038). European Acoustics Association.