Investigation of structural response and noise reduction of an acoustical enclosure using SEA method

Noise reduction capability of acoustical enclosures has been extensively investigated and is commonly quantified by noise reduction. Although much work has been done in predicting the noise reduction by using statistical energy analysis (SEA) method, discrepancy often exists between the predicted and measured results, especially at the low and intermediate frequencies. This is largely due to the fact that some physical mechanisms which affect the prediction of noise reduction were not addressed in the available SEA models. In this paper, the sources of the discrepancy were identified by investigating the limitation of SEA for energy transfer in the entire frequency range and the effect of structural–structural coupling, acoustical–structural coupling on the prediction of noise reduction. An improved SEA model including the non-resonant response and more accurate transmission coefficient of finite panels is presented. Finally, the predicted structural response and noise reduction of an acoustical enclosure were compared with measured results, and the improved agreement between the prediction and experiment was observed.

► An improved SEA model is presented in the entire frequency range.
► The accuracy of prediction at the low and intermediate frequencies is improved.
► The prediction agrees well with the measured results.