What I built was a little power grid detection system that alerted me if biters broke the grid on my defense perimeter, with a speaker every few poles apart so I could find the exact location the grid was down. Removing the polyphony since a single beep was enough.

The problem was, when many poles or the entire grid went down, my ears were in for a hell of a shock when the system went off all at once. I knew the grid stopped getting power, but my heart also stopped getting power too.
It would be nice if the client determined if the exact sound is already playing so it doesn't stack. My ears are still ringing and my volume was low at the time, so I'd thought I'd advise you of the risk before someone actually blows out their speakers or suffers a heart attack by accident.
Thank you for your time.