A practical method is proposed for determining noise contribution from a large extruded panel to the sound pressure level inside an enclosure based on acoustic measurements and numerical simulations. A finite element model is constructed for a rigid enclosure with one surface replaced with an extruded, curved panel. The interior sound pressure field is optimized using experimentally obtained reverberation time. The vibratory responses and sound intensity of the extruded panel under mechanical excitation are measured and the interior sound pressure levels are recorded. The structural-acoustic sensitivity term of the interior point is determined and used to update the vibroacoustic responses of the finite element model. The optimized numerical model can be used to predict panel noise contribution for any given excitation source.

In acoustic studies of musical string instruments, it is a common practice to identify vibration modes of the instrument resonance box. Usually, when a finite element method is employed, typical shell elements instead of solid elements are used for modelling the box, and its viscous properties are typically not taken into account. Although previous researches have indicated that this does not have much impact on the calculation of vibration modes, questions arise when the characteristics of a tonal signal are to be investigated. The problem with such modelling practice is that when shell elements are used and viscous properties are excluded, can we still effectively distinguish the subtle differences of tonal characteristics among those fine instruments. In this work we examine the effects of using different types of finite elements as well as applying viscoelastic properties of wooden materials on the tonal characteristics of sound radiation. By conducting this research for a simply structured wooden resonance box, we are attempting to answer questions such as whether we can afford to exclude either viscous properties or the use of solid elements or both in the study of tonal characteristics. If this is not permissible, then in what way these properties will affect the tonal characteristics.

In the past few years, extensive experiments have been carried out to investigate the interior noise and vibration characteristics of modern Chinese high speed trains. The relationships between the vehicle noise and vibration sources and their contributions to the interior environment are discussed. Possible airborne and structural borne sound transmission paths are identified. The vibration responses of, and sound radiation from, the roof, the floor and the sidewalls of a typical power car are presented. The noise contribution from each of these components to the overall interior sound pressure levels is examined and results are discussed.