Global acoustic sensitivity refers to a technique allowing to define the optimal modifications to a structure in order to improve its acoustic performance. The methodology is based on a structural finite element model for providing the structural sensitivities and an acoustic boundary element model selected to evaluate the acoustic sensitivities. Both models are combined within a design optimization algorithm, leading to the prediction of the optimal changes of the design parameters. Numerical implementation aspects are discussed, showing how the methodology is designed to handle real-life models. The developed technology is applied for reducing the acoustic radiation of vehicle components such as engine oilpan or gear housing and for improving the acoustic characteristics of car passenger compartments.