The motivation behind Simile's visualization tools is to provide the modeller with a continuous, immediate understanding of what the model is doing. Sometimes the best way to do this is with sounds rather than graphics. With the addition of discrete events to the modelling language, we realized that their instantaneous nature does not lend itself to the kind of graphical displays that work for continuous values.
So we created an event logger that also produces a sound each time a selected event occurs. Add an instance of this tool in the standard way, selecting 'Event sounds' from the list of helper titles. Now after clicking '+' in the helper window's toolbar, you can select a discrete event component in your model, and a sound file to play each time the event occurs. The window will show a 'ticker bar' which will move across the screen right to left, with a vertical line added each time the event occurs. Hovering over the lines will pop up the exact time and magnitude of the occurrence they represent.
Also, the sound will be played each time the event occurs. If your event has a numeric magnitude, then the volume of the sound will be determined by where each event's magnitude falls between the min and max values given for the event. Sound files in WAV format will play on all platforms -- files in other formats (e.g., mp3) may play on your particular platform but are not guaranteed to play on all.
If the chosen event occurs very frequently, or if it is in a simple model that runs very fast, the sounds may overrun each other producing unpleasant noise. In this case you can use the 'limit updates/sec' feature to slow the model execution down to the point where the sounds can be heard separately.