Study On Sound Quality Of Flexible Plate/Enclosure Coupled System

Due to the shape of most cabins are similar to that of rectangular box onengineering application, study on the interior acoustic field of flexible plate/enclosurecoupled system is crucial on the control for noise. With the development of industrialtechnology, the aim of noise control is transformed from the reduction of the signal’sA-weighted sound pressure level into improvement of sound quality based on low noiselevel. Therefore，sound quality of flexible plate/enclosure coupled system was studiedbased on two aspects including the calculation of objective psychological acousticalparameter and subject evaluation. Based on the integrated FEM/IBEM approach, thefrequency response results of the interior acoustic field for coupling system under noiseexcitation are obtained. Combined with the Zwicker’s loudness model, the loudness ofcoupling interior acoustic field is analyzed by Matlab program. Based on the bandrejectfiltering technology, the critical bands of sound signal in the enclosure which mostlyaffect the human ear’s subjective sensation are put forward by subjective experiment.The main works completed in the paper are as follows:The regularity of sound pressure frequency response function (FRF) for the pointsat variant location in the enclosed cavity is studied by using the coupled structure-acoustic method. The effects of thickness and boundary condition of coupling plate onthe sound pressure response of enclosure are also investigated. Vibration and noiseexperiment of aluminum plate/rectangular cavity coupling system is designed tovalidate the integrated FEM/IBEM is satisfactory for vibro-acoustic analysis.The variation of specific loudness for the points at variant location in the enclosureis presented based on the vibro-acoustic simulation results of flexible plate/enclosurecoupling system. The effects of thickness and boundary condition of coupling plate onthe special loudness of enclosure are also revealed.Included unfiltered signal, twenty five sound samples are obtained byfiltering the sound signal of the enclosure on the Bark scale. The subjectiveevaluation test of sound quality was carried out with the grouped pair comparisonmethod. Subjective preference scores of all sound signals were gained. The criticalbands which mostly affect the human ear’s subjective sensation are identified.