Updates the audio engine. This should be called several times per frame if irrKlang was started in single thread mode. This updates the 3d positions of the sounds as well as their volumes, effects streams and other stuff. Call this several times per frame (the more the better) if you specified irrKlang to run single threaded. Otherwise it is not necessary to use this method. This method is being called by the scene manager automaticly if you are using one, so you might want to ignore this.