Like when you strike a bell...the pitch (frequency) stays constant and the loudness decays. If this is going to be in a large venue...auditorium?...you may find that the Sonalert approach is not loud enough...unlike when it's sitting on your workbench.Hey Ken...just re-read yur post. Indeed the amplitude does change as the capacitor discharges through the piezo devices, but the frequency stays the same. Been so busy building the rest of the circuit and contestant boxes that I haven't had time to spend on the 'bell tone'. Not only do I have to build this to be customer proof, but also stagehand proof... will send pictures of the final product.
Connectors will be a big issue in making the system...bullet proof?
Keep us posted as you go.
Ken