The whole point of this post is to bump some of my suggestions:
Keybind To Reset Ambient Heat:
https://powdertoy.co.uk/Discussions/Thread/View.html?Thread=24086
Sound Effect Element:
https://powdertoy.co.uk/Discussions/Thread/View.html?Thread=24087
More Sign Types (VX/VY):
https://powdertoy.co.uk/Discussions/Thread/View.html?Thread=24071
NUCLEAR_FOX:
https://powdertoy.co.uk/Wiki/W/Previously_requested_elements.html#Sound
Yes, but in the actual suggestion, I provide sources for the sound, and a coding tutorial on how to play .WAV files in SDL2 with SDL_MIXER.
Also, the rejection text says this, "Perhaps the best that can be done is some element that plays a note sound when sparked. Entire realistic sounds for a few random reactions would not sound good though.".