Underwater noise, radiated from pile driving at offshore wind farm construction sites, has become a major issue in the course of the recent reorganization of the energy supply in Germany. To predict the sound pressure levels (SPLs) of planned wind farms and to optimize the according noise insulation systems, the need for a numerical simulation tool has arisen. In this contribution, an envisaged global model, consisting of the detailed simulation of the pile/soil-interaction, the properties of insulation measures, and the prediction of SPL in large distances from the pile, is introduced. A basic finite element (FE) model is presented which models the pile itself and the surrounding water up to a distance of 50m around the pile. This model is used to extract the acoustic source properties that are needed to couple the presented wavenumber integration (WI) code, which is utilized as a propagation method. The pile as an acoustic source is investigated in detail and feasible simplifications of the extracted output signals are suggested. Finally, the results of the WI model are compared to the FE results and an outlook on future research activities is given.