Sound field simulations for parameter predictions and for auralization are affected by several factors influencing the quality of the simulation. These factors can be combined into groups of (a) simulation input data (absorption, diffusion, directivities, etc.), (b) algorithm details (systematic and stochastic errors), (c) signal processing (filtering, HRTFs, phase generation), and (d) auralization setup (convolution hardware, sound field reproduction). The magnitude of the errors can be checked by experiments, by listening tests, and by intercomparisons. Particularly, intercomparisons gave interesting indications of error sources in the algorithms caused by simplifications and compromises between complexity and processing time. After a brief description of the software developed, the recent work on the relevant factors of auralization and the necessary efforts for obtaining reasonable results are discussed.