Soul Slay, Enslave Mind and Mind Burn (the spells) probably can't be massed in high-enough numbers to cause an effect such as this. Sound 21 (a short sound used in spells, or maybe fire breaths or something).
Here is an example mod.
Code:
#modname "Save Thy Ears"
#selectweapon 86
#sound 21
#end
#selectweapon 311
#sound 21
#end
In case anyone else wants to use it, create a new text file into your Mods folder, add in the mod commands, then rename the file from e.g. newfile.txt to thisisamod.dm . You
have to change the filetype, so make sure you didn't rename it into just thisisamod.dm.txt.